BACKGROUND: Suicide is a major public health concern globally. Accurately predicting suicidal behavior remains challenging. This study aimed to use machine learning approaches to examine the potential of the Swedish national registry data for prediction of suicidal behavior.

METHODS AND FINDINGS: The study sample consisted of 541,300 inpatient and outpatient visits by 126,205 Sweden-born patients (54% female and 46% male) aged 18 to 39 (mean age at the visit: 27.3) years to psychiatric specialty care in Sweden between January 1, 2011 and December 31, 2012. The most common psychiatric diagnoses at the visit were anxiety disorders (20.0%), major depressive disorder (16.9%), and substance use disorders (13.6%). A total of 425 candidate predictors covering demographic characteristics, socioeconomic status (SES), electronic medical records, criminality, as well as family history of disease and crime were extracted from the Swedish registry data. The sample was randomly split into an 80% training set containing 433,024 visits and a 20% test set containing 108,276 visits. Models were trained separately for suicide attempt/death within 90 and 30 days following a visit using multiple machine learning algorithms. Model discrimination and calibration were both evaluated. Among all eligible visits, 3.5% (18,682) were followed by a suicide attempt/death within 90 days and 1.7% (9,099) within 30 days. The final models were based on ensemble learning that combined predictions from elastic net penalized logistic regression, random forest, gradient boosting, and a neural network. The area under the receiver operating characteristic (ROC) curves (AUCs) on the test set were 0.88 (95% confidence interval [CI] = 0.87-0.89) and 0.89 (95% CI = 0.88-0.90) for the outcome within 90 days and 30 days, respectively, both being significantly better than chance (i.e., AUC = 0.50) (p < 0.01). Sensitivity, specificity, and predictive values were reported at different risk thresholds. A limitation of our study is that our models have not yet been externally validated, and thus, the generalizability of the models to other populations remains unknown.

CONCLUSIONS: By combining the ensemble method of multiple machine learning algorithms and high-quality data solely from the Swedish registers, we developed prognostic models to predict short-term suicide attempt/death with good discrimination and calibration. Whether novel predictors can improve predictive performance requires further investigation.

Several twin studies have investigated the overlap between attention deficit hyperactivity disorder (ADHD) and externalizing problems; however, limited information is known regarding the genetic and environmental contribution to the overlap between ADHD and internalizing problems. This study examined the genetic and environmental influences on the variation in and covariation between ADHD symptoms and internalizing problems by using the Child Behavior Checklist (CBCL). We investigated 1,316 child and adolescent twins, including 780 monozygotic twins and 536 dizygotic twins, aged 6 years to 18 years from the Chinese Child and Adolescent Twin Registry. ADHD symptoms and internalizing problems were quantified through parent rating by using the Attention Problems Scale and other three scales, which include Anxious/Depressed, Withdrawn, and Somatic Complaints of CBCL. Genetic and environmental susceptibilities common to ADHD symptoms and internalizing problems were examined through bivariate twin modeling. Results showed that genetic factors substantially influenced the ADHD symptoms with a heritability of 72%. Modest genetic influences and substantial shared environmental influences (20-77%) were observed in the three internalizing problem scales. Common genetic and shared environmental influences were essential for the overlap between ADHD and the three internalizing problems respectively. Approximately one-fifth of the genetic variance of ADHD symptoms was shared with anxiety/depression. In conclusion, substantial genetic and shared environmental influences on ADHD symptoms and internalizing problems were observed in Chinese children and adolescents. Our finding supports a common etiology between ADHD and internalizing problems. This finding can also help explain the co-existence of these behavior problems. © 2015 Wiley Periodicals, Inc.

IMPORTANCE: Traumatic events have been associated with elevated risks of psychiatric disorders, while the contributions of familial factors to these associations remain less clear.

OBJECTIVE: To determine the contribution of familial factors to long-term incidence trajectories of psychiatric disorders following potentially traumatic events.

DESIGN, SETTING, AND PARTICIPANTS: This cohort study evaluated 3 separate cohorts of individuals residing in Sweden who were free of previous diagnosed psychiatric disorders when first exposed to assault (n = 49 957), injury (n = 555 314), or bereavement (n = 321 263) from January 1987 to December 2013, together with their unexposed full siblings, and 10 age-, sex-, and birthplace-matched unexposed individuals (per exposed individual). Cohorts were created from the Swedish Total Population Register linked to health and population registers. Data were analyzed from March 2022 to April 2023.

EXPOSURES: Potentially traumatic events, including various types of assault, injuries, and bereavement (death of a child or of a spouse or partner), were ascertained from the Swedish national registers.

MAIN OUTCOMES AND MEASURES: Incident psychiatric disorders were ascertained from the Swedish Patient Register. Flexible parametric and Cox models were used to estimate associations of potentially traumatic events with incident psychiatric disorders after multivariable adjustment.

RESULTS: The median (IQR) age at exposure to assault, injury, and bereavement was 22 (18-31), 19 (8-40), and 60 (51-68) years, respectively. During a median (IQR) follow-up of 4.9 (2.2-8.2), 9.1 (4.1-15.6), and 8.1 (3.4-14.8) years, the incidence rates of any psychiatric disorder were 38.1, 13.9, and 9.0 per 1000 person-years for the exposed groups of the 3 cohorts, respectively. Elevated risk of any psychiatric disorder was observed during the first year after exposure to any assault (hazard ratio [HR], 4.55; 95% CI, 4.34-4.77), injury (HR, 3.31; 95% CI,3.23-3.38), or bereavement (HR, 2.81; 95% CI, 2.72-2.91) and thereafter (assault HR, 2.50; 95% CI, 2.43-2.56; injury HR, 1.69; 95% CI, 1.68-1.70; bereavement HR, 1.42; 95% CI, 1.40-1.44). Comparable associations were obtained in sibling comparison (first year: assault HR, 3.70; 95% CI, 3.37-4.05; injury HR, 2.98; 95% CI, 2.85-3.12; bereavement HR, 2.72; 95% CI, 2.54-2.91; thereafter: assault HR, 1.93; 95% CI, 1.84-2.02; injury HR, 1.51; 95% CI, 1.48-1.53; bereavement HR, 1.35; 95% CI, 1.31-1.38). The risk elevation varied somewhat by type of traumatic events and psychiatric disorders, with the greatest HR noted for posttraumatic stress disorder after sexual assault (sibling comparison HR, 4.52; 95% CI, 3.56-5.73 during entire follow-up period).

CONCLUSIONS AND RELEVANCE: In this study, the long-term risk elevation of psychiatric disorders after potentially traumatic events was largely independent of familial factors. The risk elevation observed immediately after these events motivates early clinical surveillance and mental health services for these vulnerable populations.

Importance Traumatic events have been associated with elevated risks of psychiatric disorders, while the contributions of familial factors to these associations remain less clear.Objective To determine the contribution of familial factors to long-term incidence trajectories of psychiatric disorders following potentially traumatic events.Design, Setting, and Participants This cohort study evaluated 3 separate cohorts of individuals residing in Sweden who were free of previous diagnosed psychiatric disorders when first exposed to assault (n = 49 957), injury (n = 555 314), or bereavement (n = 321 263) from January 1987 to December 2013, together with their unexposed full siblings, and 10 age-, sex-, and birthplace-matched unexposed individuals (per exposed individual). Cohorts were created from the Swedish Total Population Register linked to health and population registers. Data were analyzed from March 2022 to April 2023.Exposures Potentially traumatic events, including various types of assault, injuries, and bereavement (death of a child or of a spouse or partner), were ascertained from the Swedish national registers.Main Outcomes and Measures Incident psychiatric disorders were ascertained from the Swedish Patient Register. Flexible parametric and Cox models were used to estimate associations of potentially traumatic events with incident psychiatric disorders after multivariable adjustment.Results The median (IQR) age at exposure to assault, injury, and bereavement was 22 (18-31), 19 (8-40), and 60 (51-68) years, respectively. During a median (IQR) follow-up of 4.9 (2.2-8.2), 9.1 (4.1-15.6), and 8.1 (3.4-14.8) years, the incidence rates of any psychiatric disorder were 38.1, 13.9, and 9.0 per 1000 person-years for the exposed groups of the 3 cohorts, respectively. Elevated risk of any psychiatric disorder was observed during the first year after exposure to any assault (hazard ratio [HR], 4.55; 95% CI, 4.34-4.77), injury (HR, 3.31; 95% CI,3.23-3.38), or bereavement (HR, 2.81; 95% CI, 2.72-2.91) and thereafter (assault HR, 2.50; 95% CI, 2.43-2.56; injury HR, 1.69; 95% CI, 1.68-1.70; bereavement HR, 1.42; 95% CI, 1.40-1.44). Comparable associations were obtained in sibling comparison (first year: assault HR, 3.70; 95% CI, 3.37-4.05; injury HR, 2.98; 95% CI, 2.85-3.12; bereavement HR, 2.72; 95% CI, 2.54-2.91; thereafter: assault HR, 1.93; 95% CI, 1.84-2.02; injury HR, 1.51; 95% CI, 1.48-1.53; bereavement HR, 1.35; 95% CI, 1.31-1.38). The risk elevation varied somewhat by type of traumatic events and psychiatric disorders, with the greatest HR noted for posttraumatic stress disorder after sexual assault (sibling comparison HR, 4.52; 95% CI, 3.56-5.73 during entire follow-up period).Conclusions and Relevance In this study, the long-term risk elevation of psychiatric disorders after potentially traumatic events was largely independent of familial factors. The risk elevation observed immediately after these events motivates early clinical surveillance and mental health services for these vulnerable populations.

Background: Preconception, prenatal and postnatal maternal stress is associated with increased offspring psychopathology, but findings are inconsistent and need replication. We estimated associations between maternal bereavement stress and offspring autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), bipolar disorder, schizophrenia, suicide attempt and completed suicide.

Method: Using Swedish registers, we conducted the largest population-based study to date examining associations between stress exposure in 738,144 offspring born 1992-2000 for childhood outcomes and 2,155,221 offspring born 1973-1997 for adult outcomes with follow-up to 2009. Maternal stress was defined as death of a first-degree relative during (a) the 6 months before conception, (b) pregnancy or (c) the first two postnatal years. Cox proportional survival analyses were used to obtain hazard ratios (HRs) in unadjusted and adjusted analyses.

Results: Marginal increased risk of bipolar disorder and schizophrenia following preconception bereavement stress was not significant. Third-trimester prenatal stress increased the risk of ASD [adjusted HR (aHR) 1.58, 95% confidence interval (CI) 1.15-2.17] and ADHD (aHR 1.31, 95% CI 1.04-1.66). First postnatal year stress increased the risk of offspring suicide attempt (aHR 1.13, 95% CI 1.02-1.25) and completed suicide (aHR 1.51, 95% CI 1.08-2.11). Bereavement stress during the second postnatal year increased the risk of ASD (aHR 1.30, 95% CI 1.09-1.55).

Conclusions: Further research is needed regarding associations between preconception stress and psychopathological outcomes. Prenatal bereavement stress increases the risk of offspring ASD and ADHD. Postnatal bereavement stress moderately increases the risk of offspring suicide attempt, completed suicide and ASD. Smaller previous studies may have overestimated associations between early stress and psychopathological outcomes.

Background: It is unclear whether associations between fetal growth and psychiatric and socioeconomic problems are consistent with causal mechanisms.

Aims: To estimate the extent to which associations are a result of unmeasured confounding factors using a sibling-comparison approach.

Method: We predicted outcomes from continuously measured birth weight in a Swedish population cohort (n = 3 291 773), while controlling for measured and unmeasured confounding.

Results: In the population, lower birth weight (⩽ 2500 g) increased the risk of all outcomes. Sibling-comparison models indicated that lower birth weight independently predicted increased risk for autism spectrum disorder (hazard ratio for low birth weight = 2.44, 95% CI 1.99-2.97) and attention-deficit hyperactivity disorder. Although attenuated, associations remained for psychotic or bipolar disorder and educational problems. Associations with suicide attempt, substance use problems and social welfare receipt, however, were fully attenuated in sibling comparisons.

Conclusions: Results suggest that fetal growth, and factors that influence it, contribute to psychiatric and socioeconomic problems.

Background: Causal interpretation of associations between short interpregnancy interval (the duration from the preceeding birth to the conception of the next-born index child) and the offspring's psychological and educational problems may be influenced by a failure to account for unmeasured confounding.

Methods: Using population-based Swedish data from 1973-2009, we estimated the association between interpregnancy interval and outcomes [autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), severe mental illness, suicide attempt, criminality, substance-use problem and failing grades] while controlling for measured covariates. We then used cousin comparisons, post-birth intervals (the interval between the second-and third-born siblings to predict second-born outcomes) and sibling comparisons to assess the influence of unmeasured confounding. We included an exploratory analysis of long interpregnancy interval.

Results: Interpregnancy intervals of 0-5 and 6-11 months were associated with higher odds of outcomes in cohort analyses. Magnitudes of association were attenuated following adjustment for measured covariates. Associations were eliminated for ADHD, severe mental illness and failing grades, but maintained magnitude for ASD, suicide attempt, criminality and substance-use problem in cousin comparisons. Post-birth interpregnancy interval and sibling comparisons suggested some familial confounding. Associations did not persist across models of long interpregnancy interval.

Conclusions: Attenuation of the association in cousin comparisons and comparable post-birth interval associations suggests that familial genetic or environmental confounding accounts for a majority of the association for ADHD, severe mental illness and failing grades. Modest associations appear independently of covariates for ASD, suicide attempt, criminality and substance-use problem. Post-birth analyses and sibling comparisons, however, show some confounding in these associations.

The aim was to further test the reliability and validity of a newly developed instrument designed to assess psychopathic personality traits in children, the Child Problematic Traits Inventory (CPTI). Data from the Preschool Twin Study in Sweden were used, a national general population study of 5-year-old twins (n = 1,188, 50.3% girls). Both preschool teachers and parents were used as informants. Confirmatory factor analysis replicated the intended three-factorial structure of the 28 items of the CPTI. Overall, our findings demonstrated good internal consistency and convergent validity, with all the teacher-rated CPTI scores being associated with teacher and parent ratings of externalizing psychopathology, aggressive behavior, fearlessness, and prosocial peer involvement. In conclusion, the CPTI hold promise as a teacher-rated tool for assessing psychopathic traits in childhood, though more research is needed to see if these findings can be generalized to other countries, settings, and older children.

INTRODUCTION: Sleep disorders represent an important comorbidity in individuals with ADHD. While the links between ADHD and sleep disturbances have been extensively investigated, research on the management of sleep disorders in individuals with ADHD is relatively limited, albeit expanding.

AREAS COVERED: The authors searched PubMed, Medline, PsycInfo, Embase+Embase Classic, Web of Sciences databases, and clinicaltrials.gov up to 4 January 2024, for randomized controlled trials (RCTs) of any intervention for sleep disorders associated with ADHD. They retained 16 RCTs (eight on pharmacological and eight on non-pharmacological interventions), supporting behavioral intervention and melatonin, and nine ongoing RCTs registered on clinicaltrials.gov.

EXPERT OPINION: The pool of RCTs testing interventions for sleep disorders in individuals with ADHD is expanding. However, to inform clinical guidelines, there is a need for additional research in several areas, including 1) RCTs based on a precise phenotyping of sleep disorders; 2) pragmatic RCTs recruiting neurodevelopmental populations representative of those seen in clinical services; 3) trials testing alternative interventions (e.g. suvorexant or light therapy) or ways to deliver them (e.g. online); 4) sequential and longer-term RCTs; 5) studies testing the impact of sleep interventions on outcomes other than sleep; 6) and implementation of advanced evidence synthesis and precision medicine approaches.

INTRODUCTION: Although several systematic reviews (SRs)/meta-analyses (MAs) on the association between specific mental disorders and specific somatic conditions are available, an overarching evidence synthesis across mental disorders and somatic conditions is currently lacking. We will conduct an umbrella review of SRs/MAs to test: 1) the strength of the association between individual mental disorders and individual somatic conditions in children/adolescents and adults; 2) to which extent associations are specific to individual mental and somatic conditions .

METHODS AND ANALYSIS: We will search a broad set of electronic databases and contact study authors. We will include SRs with MA or SRs reporting the effect size from individual studies on the association between a number of somatic and mental conditions (as per the International Classification of Diseases, 11th Revision). We will follow an algorithm to select only one SR or MA when more than one are available on the same association. We will rate the quality of included SRs/MAs using the AMSTAR-2 tool. We will assess to which extent mental disorders are selectively associated with specific somatic conditions or if there are transdiagnostic, across-spectra or diagnostic spectrum-specific associations between mental disorders and somatic conditions based on the Transparent, Reporting, Appraising, Numerating, Showing (TRANSD) recommendations.

DISCUSSION: The present umbrella review will shed light on the association between mental health disorders and somatic conditions, providing useful data for the care of patients with mental health disorders, in particular for early detection and intervention. This work might also add insight to the pathophysiology of mental health conditions, and contribute to the current debate on the value of a transdiagnostic approach in psychiatry.

Data on incidence, prevalence and burden of ADHD are crucial for clinicians, patients, and stakeholders. We present the incidence, prevalence, and burden of ADHD globally and across countries from 1990 to 2019 from the Global Burden of Disease (GBD) study. We also: (1) calculated the ADHD prevalence based on data actually collected as opposed to the prevalence estimated by the GBD with data imputation for countries without prevalence data; (2) discussed the GBD estimated ADHD burden in the light of recent meta-analytic evidence on ADHD-related mortality. In 2019, GBD estimated global age-standardized incidence and prevalence of ADHD across the lifespan at 0.061% (95%UI = 0.040-0.087) and 1.13% (95%UI = 0.831-1.494), respectively. ADHD accounted for 0.8% of the global mental disorder DALYs, with mortality set at zero by the GBD. From 1990 to 2019 there was a decrease of -8.75% in the global age-standardized prevalence and of -4.77% in the global age-standardized incidence. The largest increase in incidence, prevalence, and burden from 1990 to 2019 was observed in the USA; the largest decrease occurred in Finland. Incidence, prevalence, and DALYs remained approximately 2.5 times higher in males than females from 1990 to 2019. Incidence peaked at age 5-9 years, and prevalence and DALYs at age 10-14 years. Our re-analysis of data prior to 2013 showed a prevalence in children/adolescents two-fold higher (5.41%, 95% CI: 4.67-6.15%) compared to the corresponding GBD estimated prevalence (2.68%, 1.83-3.72%), with no significant differences between low- and middle- and high-income countries. We also found meta-analytic evidence of significantly increased ADHD-related mortality due to unnatural causes. While it provides the most detailed evidence on temporal trends, as well as on geographic and sex variations in incidence, prevalence, and burden of ADHD, the GBD may have underestimated the ADHD prevalence and burden. Given the influence of the GBD on research and policies, methodological issues should be addressed in its future editions.

Background: Several studies have assessed the possible association between attention deficit hyperactivity disorder (ADHD) and asthma. However, existing evidence is inconclusive as to whether this association remains after controlling for possible important confounders. To fill this knowledge gap, we did a systematic review and meta-analysis, followed by a population-based study.

Methods: For the systematic review and meta-analysis, we searched PubMed, PsycINFO, Embase, Embase Classic, Ovid MEDLINE, and Web of Knowledge databases up to Oct 31, 2017, for observational studies allowing estimation of the association between asthma and ADHD. No restrictions to date, language, or article type were applied. Unpublished data were collected from authors of the identified studies. We extracted unadjusted and adjusted odds ratios (ORs) from the identified studies and calculated ORs when they were not reported. We assessed study quality using the Newcastle-Ottawa Scale and study heterogeneity using I (2) statistics. A random-effects model was used to calculate pooled ORs. The systematic review is registered with PROSPERO (CRD42017073368). To address the fact that the ORs obtained in the meta-analysis were adjusted for confounders that inevitably varied across studies, we did a population-based study of individuals in multiple national registers in Sweden. We calculated an unadjusted OR and an OR that was simultaneously adjusted for all confounders identified in a directed acyclic graph based on the studies of asthma and ADHD identified in our systematic review.

Findings: We identified 2649 potentially eligible citations, from which we obtained 49 datasets including a total of 210 363 participants with ADHD and 3 115 168 without. The pooled unadjusted OR was 1.66 (95% CI 1.22-2.26; I-2 = 99.47) and the pooled adjusted OR was 1.53 (1.41-1.65; I-2 = 50.76), indicating a significant association between asthma and ADHD. Possible lack of representativeness of the study population was detected with the Newcastle-Ottawa Scale in 42 of 49 datasets. In the population-based study, we included 1 575 377 individuals born between Jan 1, 1992, and Dec 31, 2006, of whom 259 253 (16.5%) had asthma and 57 957 (3.7%) had ADHD. Asthma was significantly associated with ADHD (OR 1.60, 95% CI 1.57-1.63) in the crude model adjusting for sex and year of birth, and this association remained significant after simultaneous adjustment for all covariates (1.45, 1.41-10.48).

Interpretation: The combined results of the meta-analysis and the population-based study support a significant association between asthma and ADHD, which remained even after simultaneously controlling for several possible confounders in the population-based study. Awareness of this association might help to reduce delay in the diagnosis of both ADHD and asthma.

Objective: To assess the associations of 43 autoimmune diseases with the subsequent risk of ALS and further evaluate the contribution of familial confounding to these associations.

Methods: We conducted a nationwide register-based nested case-control study including 3561 ALS patients diagnosed during 1990-2013 in Sweden and 35,610 controls that were randomly selected from the general population and individually matched to the cases on age, sex, and county of birth. To evaluate the contribution of familial factors on the studied association, we additionally studied the first-degree relatives (siblings and children) of ALS patients and their controls.

Results: Patients with ALS had a 47% higher risk of being previously diagnosed with autoimmune disease (OR 1.47, 95% confidence interval [CI] 1.31-1.64), compared with controls. A positive association was noted for several autoimmune diseases, including myasthenia gravis, polymyositis or dermatomyositis, Guillain-Barre syndrome, type 1 diabetes diagnosed younger than 30 years, multiple sclerosis, and hypothyreosis. The increased risk of any autoimmune disease was greatest during the year before ALS diagnosis, likely due to misdiagnosis. A statistically significantly increased risk was also noted during 2-5 years, but not earlier, before ALS diagnosis. First-degree relatives of ALS patients had however no increased risk of autoimmune diseases compared with first-degree relatives of controls.

Conclusions: Although it is difficult to completely remove the potential effects of misdiagnosis, there is likely a positive association between autoimmune disease (such as type 1 diabetes and multiple sclerosis) and ALS, which is not fully explained by shared familial confounding factors. 

Darier disease (DD) is a rare monogenetic skin disorder with limited data on its potential association with neurological disorders. This study aimed to investigate the association between DD and neurological disorders, specifically Parkinson's disease, dementias, and epilepsy. Using Swedish national registers in a period spanning between 1977 and 2013, 935 individuals with DD were compared with up to 100 comparison individuals each, randomly selected from the general population based on birth year, sex, and county of residence at the time of the first diagnosis of DD. Individuals with DD had increased risks of being diagnosed with Parkinson's disease (RR 2.1, CI 1.1; 4.4), vascular dementia (RR 2.1, CI 1.0; 4.2), and epilepsy, (RR 2.5, CI 1.8; 3.5). No association of DD with other dementias were detected. This study demonstrates a new association between DD and neurodegenerative disorders and epilepsy, underlining the need for increased awareness, interdisciplinary collaboration, and further research to understand the underlying mechanisms. Early identification and management of neurological complications in DD patients could improve treatment strategies and patient outcomes. The findings also highlight the role of SERCA2 in the pathophysiology of neurological disorders, offering new targets for future research and potentials for novel treatments.

Patients with Darier disease have an increased risk of depression and anxiety, which agrees with patterns of increased prescription of antidepressants and anxiolytics in people with the disease.

BACKGROUND: BIPCOM aims to (1) identify medical comorbidities in people with bipolar disorder (BD); (2) examine risk factors and clinical profiles of Medical Comorbidities (MC) in this clinical group, with a special focus on Metabolic Syndrome (MetS); (3) develop a Clinical Support Tool (CST) for the personalized management of BD and medical comorbidities.

METHODS: The BIPCOM project aims to investigate MC, specifically MetS, in individuals with BD using various approaches. Initially, prevalence rates, characteristics, genetic and non-genetic risk factors, and the natural progression of MetS among individuals with BD will be assessed by analysing Nordic registers, biobanks, and existing patient datasets from 11 European recruiting centres across 5 countries. Subsequently, a clinical study involving 400 participants from these sites will be conducted to examine the clinical profiles and incidence of specific MetS risk factors over 1 year. Baseline assessments, 1-year follow-ups, biomarker analyses, and physical activity measurements with wearable biosensors, and focus groups will be performed. Using this comprehensive data, a CST will be developed to enhance the prevention, early detection, and personalized treatment of MC in BD, by incorporating clinical, biological, sex and genetic information. This protocol will highlight the study's methodology.

DISCUSSION: BIPCOM's data collection will pave the way for tailored treatment and prevention approaches for individuals with BD. This approach has the potential to generate significant healthcare savings by preventing complications, hospitalizations, and emergency visits related to comorbidities and cardiovascular risks in BD. BIPCOM's data collection will enhance BD patient care through personalized strategies, resulting in improved quality of life and reduced costly interventions. The findings of the study will contribute to a better understanding of the relationship between medical comorbidities and BD, enabling accurate prediction and effective management of MetS and cardiovascular diseases.

TRIAL REGISTRATION: ISRCTN68010602 at https://www.isrctn.com/ISRCTN68010602 . Registration date: 18/04/2023.

BACKGROUND: Emerging evidence points at substantial comorbidity between adult attention deficit hyperactivity disorder (ADHD) and cardiometabolic diseases, but our understanding of the comorbidity and how to manage cardiometabolic disease in adults with ADHD is limited. The ADHD Remote Technology study of cardiometabolic risk factors and medication adherence (ART-CARMA) project uses remote measurement technology to obtain real-world data from daily life to assess the extent to which ADHD medication treatment and physical activity, individually and jointly, may influence cardiometabolic risks in adults with ADHD. Our second main aim is to obtain valuable real-world data on adherence to pharmacological treatment and its predictors and correlates during daily life from adults with ADHD.

METHODS: ART-CARMA is a multi-site prospective cohort study within the EU-funded collaboration 'TIMESPAN' (Management of chronic cardiometabolic disease and treatment discontinuity in adult ADHD patients) that will recruit 300 adults from adult ADHD waiting lists. The participants will be monitored remotely over a period of 12 months that starts from pre-treatment initiation. Passive monitoring, which involves the participants wearing a wrist-worn device (EmbracePlus) and downloading the RADAR-base Passive App and the Empatica Care App on their smartphone, provides ongoing data collection on a wide range of variables, such as physical activity, sleep, pulse rate (PR) and pulse rate variability (PRV), systolic peaks, electrodermal activity (EDA), oxygen saturation (SpO2), peripheral temperature, smartphone usage including social connectivity, and the environment (e.g. ambient noise, light levels, relative location). By combining data across these variables measured, processes such as physical activity, sleep, autonomic arousal, and indicators of cardiovascular health can be captured. Active remote monitoring involves the participant completing tasks using a smartphone app (such as completing clinical questionnaires or speech tasks), measuring their blood pressure and weight, or using a PC/laptop (cognitive tasks). The ART system is built on the RADAR-base mobile-health platform.

DISCUSSION: The long-term goal is to use these data to improve the management of cardiometabolic disease in adults with ADHD, and to improve ADHD medication treatment adherence and the personalisation of treatment.

OBJECTIVE: This study examined the prospective, potentially bidirectional association of aggressive behavior with BMI and body composition across childhood in three population-based cohorts.

METHODS: Repeated measures of aggression and BMI were available from the Generation R Study between ages 6 and 10 years (N = 3,974), the Netherlands Twin Register (NTR) between ages 7 and 10 years (N = 10,328), and the Swedish Twin Study of Child and Adolescent Development (TCHAD) between ages 9 and 14 years (N = 1,462). In all samples, aggression was assessed with the Child Behavior Checklist. Fat mass and fat-free mass were available in the Generation R Study. Associations were examined with cross-lagged modeling.

RESULTS: Aggressive behavior at baseline was associated with higher BMI at follow-up in the Generation R Study (β = 0.02, 95% CI: 0.00 to 0.04), in NTR (β = 0.04, 95% CI: 0.02 to 0.06), and in TCHAD (β = 0.03, 95% CI: -0.02 to 0.07). Aggressive behavior was prospectively associated with higher fat mass (β = 0.03, 95% CI: 0.01 to 0.05) but not fat-free mass. There was no evidence that BMI or body composition preceded aggressive behavior.

CONCLUSIONS: More aggressive behavior was prospectively associated with higher BMI and fat mass. This suggests that aggression contributes to the obesity problem, and future research should study whether these behavioral pathways to childhood obesity are modifiable.

Little is known about the etiology of avoidant/restrictive food intake disorder (ARFID) and no twin studies of ARFID exist yet. Validated screening instruments for ARFID are only starting to emerge and accordingly, few large-scale epidemiological studies specifically aimed at measuring ARFID are available. We leveraged the rich existing datasets of the Swedish Twin Registry to develop a proxy for the ARFID phenotype and determine its twin-based heritability. We extracted all data relevant to ARFID from the Child and Adolescent Twin Study in Sweden and national health registers, and identified children with avoidant/restrictive eating with clinically significant impact, but without body image concerns such as fear of weight gain and excluding major medical illnesses that could account for the eating behavior. Among 34,382 twins born 1992–2010, 678 children (2.0%, 39% female) were identified with the ARFID phenotype between age 6 and 12 years. In the best fitting model, variation in the liability to ARFID was largely explained by additive genetic factors (0.80, 95% confidence interval [CI] 0.71–0.86), with significant contributions from non-shared environmental factors (0.20, 95% CI 0.14–0.29) and sibling contrast effects (-0.11, 95% CI -0.16—-0.04). Prevalence and sex distribution of the ARFID phenotype were similar to previous studies, supporting the use of epidemiological data to identify ARFID. This first heritability estimate of ARFID suggests that ARFID is highly heritable, encouraging future twin and molecular genetic studies. In a next step we will use multivariate twinmodels to test whether, etiologically, ARFID is related to neurod-velopmental disorders.

IMPORTANCE: Avoidant restrictive food intake disorder (ARFID) is characterized by an extremely limited range and/or amount of food eaten, resulting in the persistent failure to meet nutritional and/or energy needs. Its etiology is poorly understood, and knowledge of genetic and environmental contributions to ARFID is needed to guide future research. OBJECTIVE: To estimate the extent to which genetic and environmental factors contribute to the liability to the broad ARFID phenotype.

DESIGN, SETTING, AND PARTICIPANTS: This nationwide Swedish twin study includes 16 951 twin pairs born between 1992 and 2010 whose parents participated in the Child and Adolescent Twin Study in Sweden (CATSS) at twin age 9 or 12 years. CATSS was linked to the National Patient Register (NPR) and the Prescribed Drug Register (PDR). Data were collected from July 2004 to April 2020, and data were analyzed from October 2021 to October 2022.

MAIN OUTCOMES AND MEASURES: From CATSS, NPR, and PDR, all parent reports, diagnoses, procedures, and prescribed drugs that were relevant to the DSM-5 ARFID criteria were extracted when twin pairs were aged 6 to 12 years and integrated into a composite measure for the ARFID phenotype (ie, avoidant/restrictive eating with clinically significant impact, such as low weight or nutritional deficiency, and with fear of weight gain as an exclusion). In sensitivity analyses, autism and medical conditions that could account for the eating disturbance were controlled for. Univariate liability threshold models were fitted to estimate the relative contribution of genetic and environmental variation to the liability to the ARFID phenotype.

RESULTS: Of 33 902 included children, 17 151 (50.6%) were male. A total of 682 children (2.0%) with the ARFID phenotype were identified. The heritability of ARFID was 0.79 (95% CI, 0.70-0.85), with significant contributions from nonshared environmental factors (0.21; 95% CI, 0.15-0.30). Heritability was very similar when excluding children with autism (0.77; 95% CI, 0.67-0.84) or medical illnesses that could account for the eating disturbance (0.79; 95% CI, 0.70-0.86).

CONCLUSIONS AND RELEVANCE: Prevalence and sex distribution of the broad ARFID phenotype were similar to previous studies, supporting the use of existing epidemiological data to identify children with ARFID. This study of the estimated genetic and environmental etiology of ARFID suggests that ARFID is highly heritable, encouraging future twin and molecular genetic studies.

Background: Available prediction models ofcardiovascular diseases (CVDs) may not accuratelypredict outcomes among individuals initiatingpharmacological treatment for attention-deficit/hyperactivity disorder (ADHD).

Objective: To improve the predictive accuracyof traditional CVD risk factors for adults initiatingpharmacological treatment of ADHD, by consideringnovel CVD risk factors associated with ADHD (comorbidpsychiatric disorders, sociodemographic factors andpsychotropic medication).

Methods: The cohort composed of 24 186 adultsresiding in Sweden without previous CVDs, born between1932 and 1990, who started pharmacological treatmentof ADHD between 2008 and 2011, and were followedfor up to 2 years. CVDs were identified using diagnosesaccording to the International Classification of Diseases,and dispended medication prescriptions from Swedishnational registers. Cox proportional hazards regressionwas employed to derive the prediction model.

Findings: The developed model included eighttraditional and four novel CVD risk factors. Themodel showed acceptable overall discrimination (Cindex=0.72, 95% CI 0.70 to 0.74) and calibration(Brier score=0.008). The Integrated DiscriminationImprovement index showed a significant improvementafter adding novel risk factors (0.003 (95% CI 0.001 to0.007), p<0.001).

Conclusions: The inclusion of the novel CVD riskfactors may provide a better prediction of CVDs in thispopulation compared with traditional CVD predictorsonly, when the model is used with a continuous riskscore. External validation studies and studies assessingclinical impact of the model are warranted.

Clinical implications: Individuals initiatingpharmacological treatment of ADHD at higher risk ofdeveloping CVDs should be more closely monitored.

BACKGROUND: Emerging research suggests that attention-deficit/hyperactivity disorder (ADHD) increases the risk for cardiovascular (CVDs) and metabolic disorders (i.e., cardiometabolic disorders) in adulthood. Yet, available studies are scarce and have mainly been focused on individuals receiving clinical ADHD diagnoses. We aimed to investigate the prospective associations of ADHD symptoms in young and mid-adulthood with subsequent cardiometabolic disorders and the underlying mechanisms.

METHODS: We studied 10,394 twins from the Swedish Twin Registry (STR), born between 1958 and 1985 without previous medical history of cardiometabolic disorders. They provided self-assessment of ADHD symptoms (score range 0-36) via a validated, DSM-IV-based scale in a web-based questionnaire/telephone interview within the Study of Twin Adults: Genes and Environment (STAGE), in 2005-2006 (aged 19-47 years), and were followed until the end of 2018 (33-59 years) to identify incident clinical diagnoses/medication prescriptions for cardiometabolic disorders acquired from Swedish national registers. We used Cox regression models to investigate the associations between ADHD symptoms score and cardiometabolic outcomes, with and without adjustment for relevant covariates, and a co-twin control design to study familial confounding.

RESULTS: A one-unit increase in the level of ADHD symptoms was associated with a 2% increase in the rate of CVDs (hazard ratio [HR] = 1.02, 95% confidence interval 1.01-1.04) and a 3% increase in the rate of metabolic disorders (HR = 1.03, 1.02-1.05), after adjusting for birth year and sex. The associations were no longer significant after adjusting for educational attainment, lifestyle factors, and comorbid psychiatric disorders. The associations remained significant after adjusting for familial factors shared by dizygotic twin pairs but became nonsignificant after adjusting for factors shared by monozygotic twin pairs. However, the strength of the associations attenuated significantly in monozygotic twins compared to dizygotic twins for CVDs only, suggesting genetic confounding.

CONCLUSIONS: ADHD symptom score is associated with a higher risk for cardiometabolic disorders, which may be explained by lower educational attainment, adverse lifestyle factors, and psychiatric comorbidities. Moreover, the associations appear to be partly confounded by shared genetic factors, especially for CVDs. Further research is needed to investigate the identified associations at the level of individual cardiometabolic disorders and to follow-up participants until a more advanced older age.

INTRODUCTION: There is a striking knowledge gap on ADHD in older adults, and the diagnosis as well as treatment for ADHD in this age group.

AREAS COVERED: The authors first review the literature on the prevalence, functional impairment, and health comorbidities of ADHD across the lifespan. Next, they address the diagnostic criteria for ADHD in adults according to the DSM/ICD, available screening/diagnostic tools, differential diagnosis, and the validity of diagnostic criteria for ADHD in older adults. Finally, the authors focus on empirical evidence on the prevalence rates, medication response, and safety of pharmacological treatment of ADHD in older adults, and national and international clinical guidelines on the treatment of ADHD in this age group. E

XPERT OPINION: It is expected that future editions of the DSM and ICD will provide specifiers to the standard ADHD criteria, to better inform the diagnosis of ADHD in older adults. It is also expected that the increasing number of epidemiological studies will provide rigorous estimates on the prevalence, incidence, and burden of ADHD in older adults. One may expect an increasing number of RCTs assessing the efficacy/effectiveness and tolerability/safety of pharmacological as well as non-pharmacological interventions which will inform future guidelines on ADHD in older adults.

There is a significant knowledge gap in research on Attention-Deficit/Hyperactivity Disorder (ADHD) in older adults. Via a systematic review and meta-analysis, we aimed to investigate the prevalence of ADHD in older adults, considering different assessment methods. We searched five electronic databases up to June 26, 2020. We identified 20 relevant studies with 32 datasets providing a total sample size of 20,999,871 individuals (41,420 individuals with ADHD). The pooled prevalence estimates differed significantly across assessment methods: 2.18 % (95 % CI = 1.51, 3.16) based on research diagnosis via validated scales, 0.23 % (0.12, 0.43) relying on clinical ADHD diagnosis, and 0.09 % (0.06, 0.15) based on ADHD treatment rates. Heterogeneity was significant across studies for all assessment methods. There is a considerable number of older adults with elevated levels of ADHD symptoms as determined via validated scales, and the prevalence of treated ADHD is less than half of the prevalence of clinically diagnosed ADHD. This highlights the need for increased awareness of ADHD clinical diagnosis and treatment in older adults.

Background: Previous research has indicated that attention-deficit/hyperactivity disorder (ADHD) is associated with an increased risk for dementia, but studies are scarce and inconclusive. We aimed to investigate the association between ADHD, and dementia and mild cognitive impairment (MCI). Additionally, we aimed to investigate the impact of comorbid conditions, educational attainment, head injuries, other developmental disorders, and sex on the association.

Methods: The study population consisted of 3,591,689 individuals born between 1932 and 1963, identified from Swedish population-based registers. Cases of ADHD, dementia and MCI were defined according to ICD diagnostic codes and ATC codes for medication prescriptions. A Cox proportional hazards model was used to test the associations between ADHD, and dementia and MCI.

Results: Individuals with ADHD had an increased risk for dementia and MCI. After adjusting for sex and birth year, a hazard ratio (HR) was 2.92 (95% confidence interval 2.40-3.57) for dementia, and 6.21 (5.25-7.35) for MCI. Additional adjustment for psychiatric disorders (depression, anxiety, substance use disorder, and bipolar disorder) substantially attenuated the associations, HR = 1.62 (1.32-1.98) for dementia, and 2.54 (2.14-3.01) for MCI. Common metabolic disorders (hypertension, type 2 diabetes, and obesity), sleep disorders, head injuries, educational attainment, and other developmental disorders, had a limited impact on the association. The association between ADHD and dementia was stronger in men.

Conclusions: ADHD is a potential risk factor for dementia and MCI, although the risk significantly attenuates after controlling for psychiatric disorders. Further research is needed to confirm these findings and to explore underlying mechanisms of the associations.

BACKGROUND: Little is known about the impact of cumulative attention-deficit/hyperactivity disorder (ADHD) medication use on the risk of type 2 diabetes (T2D).

OBJECTIVE: The objective is to examine the association between cumulative use of ADHD medication and risk of incident T2D.

METHODS: A nested case-control study was conducted in a national cohort of individuals aged 18-70 years with incident ADHD (n=138 778) between 2007 and 2020 through Swedish registers. Individuals with incident T2D after ADHD were selected as cases (n=2355) and matched with up to five controls (n=11 681) on age at baseline, sex and birth year. Conditional logistic regression models examined the association between cumulative duration of ADHD medication use and T2D.

FINDINGS: Compared with no use, a decreased risk of T2D was observed for those on cumulative use of ADHD medications up to 3 years (ORs: 0<duration≤1 year, 0.79 (95% CI, 0.69 to 0.91); 1<duration≤3 years, 0.80 (95% CI, 0.69 to 0.92); duration>3 years, 0.97 (95% CI, 0.84 to 1.12)). When investigating medication types separately, methylphenidate showed results similar to main analyses, lisdexamfetamine showed no association with T2D, whereas long-term (>3 years) use of atomoxetine was associated with an increased risk of T2D (OR: 1.44 (95% CI, 1.01 to 2.04)).

CONCLUSION: Cumulative use of ADHD medication does not increase the risk for T2D, with the exception of long-term use of atomoxetine. CLINICAL IMPLICATIONS: Findings suggest that clinicians should be aware of the potential risk of T2D associated with the cumulative use of atomoxetine among patients with ADHD; however, further replication is strongly needed.

The Developmental Origin of Health and Disease (DOHaD) hypothesis is a broad theoretical framework that emphasizes how early risk factors have a causal influence on psychopathology. Researchers have raised concerns about the causal interpretation of statistical associations between early risk factors and later psychopathology because most existing studies have been unable to rule out the possibility of environmental and genetic confounding. In this paper we illustrate how family-based quasi-experimental designs can test the DOHaD hypothesis by ruling out alternative hypotheses. We review the logic underlying sibling-comparison, co-twin control, offspring of siblings/twins, adoption, and in vitro fertilization designs. We then present results from studies using these designs focused on broad indices of fetal development (low birth weight and gestational age) and a particular teratogen, smoking during pregnancy. The results provide mixed support for the DOHaD hypothesis for psychopathology, illustrating the critical need to use design features that rule out unmeasured confounding.

Importance: Preterm birth is associated with increased mortality and morbidity. However, previous studies have been unable to rigorously examine whether confounding factors cause these associations rather than the harmful effects of being born preterm.

Objective: To estimate the extent to which the associations between early gestational age and offspring mortality and morbidity are the result of confounding factors by using a quasi-experimental design, the sibling-comparison approach, and by controlling for statistical covariates that varied within families.

Design, setting and participants: A population-based cohort study, combining Swedish registries to identify all individuals born in Sweden from 1973 to 2008 (3,300,708 offspring of 1,736,735 mothers) and link them with multiple outcomes.

Main outcomes and measures: Offspring mortality (during infancy and throughout young adulthood) and psychiatric (psychotic or bipolar disorder, autism, attention-deficit/hyperactivity disorder, suicide attempts, substance use, and criminality), academic (failing grades and educational attainment), and social (partnering, parenthood, low income, and social welfare benefits) outcomes through 2009.

Results: In the population, there was a dose-response relationship between early gestation and the outcome measures. For example, extreme preterm birth (23-27 weeks of gestation) was associated with infant mortality (odds ratio, 288.1; 95% CI, 271.7-305.5), autism (hazard ratio [HR], 3.2; 95% CI, 2.6-4.0), low educational attainment (HR, 1.7; 1.5-2.0), and social welfare benefits (HR, 1.3; 1.2-1.5) compared with offspring born at term. The associations between early gestation and mortality and psychiatric morbidity generally were robust when comparing differentially exposed siblings and controlling for statistical covariates, whereas the associations with academic and some social problems were greatly or completely attenuated in the fixed-effects models.

Conclusions and relevance: The mechanisms responsible for the associations between preterm birth and mortality and morbidity are outcome-specific. Associations between preterm birth and mortality and psychiatric morbidity are largely independent of shared familial confounds and measured covariates, consistent with a causal inference. However, some associations, particularly predicting suicide attempt, educational attainment, and social welfare benefits, are the result of confounding factors. The findings emphasize the importance of both reducing preterm birth and providing wraparound services to all siblings in families with an offspring born preterm.

Prominent developmental theories posit a causal link between early-life exposures and later functioning. Yet, observed associations with early exposures may not reflect causal effects because of genetic and environmental confounding. The current manuscript describes how a systematic series of epidemiologic analyses that combine several genetically-informative designs and statistical approaches can help distinguish between competing theories. In particular, the manuscript details how combining the use of measured covariates with sibling-comparisons, cousin-comparisons, and additional designs can help elucidate the sources of covariation between early-life exposures and later outcomes, including the roles of (a) factors that are not shared in families, including a potential causal effect of the exposure; (b) carryover effects from the exposure of one child to the next; and (c) familial confounding. We also describe key assumptions and how they can be critically evaluated. Furthermore, we outline how subsequent analyses, including effect decomposition with respect to measured, plausible mediators, and quantitative genetic models can help further specify the underlying processes that account for the associations between early-life exposures and offspring outcomes.

Importance: Advancing paternal age is associated with increased genetic mutations during spermatogenesis, which research suggests may cause psychiatric morbidity in the offspring. The effects of advancing paternal age at childbearing on offspring morbidity remain unclear, however, because of inconsistent epidemiologic findings and the inability of previous studies to rigorously rule out confounding factors.

Objective: To examine the associations between advancing paternal age at childbearing and numerous indexes of offspring morbidity.

Design, setting and participants: We performed a population-based cohort study of all individuals born in Sweden in 1973-2001 (N = 2,615,081), with subsets of the data used to predict childhood or adolescent morbidity. We estimated the risk of psychiatric and academic morbidity associated with advancing paternal age using several quasi-experimental designs, including the comparison of differentially exposed siblings, cousins, and first-born cousins.

Exposure: Paternal age at childbearing.

Main outcomes and measures: Psychiatric (autism, attention-deficit/hyperactivity disorder, psychosis, bipolar disorder, suicide attempt, and substance use problem) and academic (failing grades and low educational attainment) morbidity.

Results: In the study population, advancing paternal age was associated with increased risk of some psychiatric disorders (eg, autism, psychosis, and bipolar disorders) but decreased risk of the other indexes of morbidity. In contrast, the sibling-comparison analyses indicated that advancing paternal age had a dose-response relationship with every index of morbidity, with the magnitude of the associations being as large or larger than the estimates in the entire population. Compared with offspring born to fathers 20 to 24 years old, offspring of fathers 45 years and older were at heightened risk of autism (hazard ratio [HR] = 3.45; 95% CI, 1.62-7.33), attention-deficit/hyperactivity disorder (HR = 13.13; 95% CI, 6.85-25.16), psychosis (HR = 2.07; 95% CI, 1.35-3.20), bipolar disorder (HR = 24.70; 95% CI, 12.12-50.31), suicide attempts (HR = 2.72; 95% CI, 2.08-3.56), substance use problems (HR = 2.44; 95% CI, 1.98-2.99), failing a grade (odds ratio [OR] = 1.59; 95% CI, 1.37-1.85), and low educational attainment (OR = 1.70; 95% CI, 1.50-1.93) in within-sibling comparisons. Additional analyses using several quasi-experimental designs obtained commensurate results, further strengthening the internal and external validity of the findings.

Conclusions and relevance: Advancing paternal age is associated with increased risk of psychiatric and academic morbidity, with the magnitude of the risks being as large or larger than previous estimates. These findings are consistent with the hypothesis that new genetic mutations that occur during spermatogenesis are causally related to offspring morbidity.

Context: Previous epidemiological, animal, and human cognitive neuroscience research suggests that maternal smoking during pregnancy (SDP) causes increased risk of substance use/problems in offspring.

Objective: To determine the extent to which the association between SDP and offspring substance use/problems depends on confounded familial background factors by using a quasi-experimental design.

Design: We used 2 separate samples from the United States and Sweden. The analyses prospectively predicted multiple indices of substance use and problems while controlling for statistical covariates and comparing differentially exposed siblings to minimize confounding.

Setting: Offspring of a representative sample of women in the United States (sample 1) and the total Swedish population born during the period from January 1, 1983, to December 31, 1995 (sample 2).

Patients or Other Participants: Adolescent offspring of the women in the National Longitudinal Survey of Youth 1979 (n = 6904) and all offspring born in Sweden during the 13-year period (n = 1,187,360).

Main Outcome Measures: Self-reported adolescent alcohol, cigarette, and marijuana use and early onset (before 14 years of age) of each substance (sample 1) and substance-related convictions and hospitalizations for an alcohol- or other drug-related problem (sample 2).

Results: The same pattern emerged for each index of substance use/problems across the 2 samples. At the population level, maternal SDP predicted every measure of offspring substance use/problems in both samples, ranging from adolescent alcohol use (hazard ratio [HR](moderate), 1.32 [95% CI, 1.22-1.43]; HR(high), 1.33 [1.17-1.53]) to a narcotics-related conviction (HR(moderate), 2.23 [2.14-2.31]; HR(high), 2.97 [2.86-3.09]). When comparing differentially exposed siblings to minimize genetic and environmental confounds, however, the association between SDP and each measure of substance use/problems was minimal and not statistically significant.

Cocnlusions: The association between maternal SDP and offspring substance use/problems is likely due to familial background factors, not a causal influence, because siblings have similar rates of substance use and problems regardless of their specific exposure to SDP.

The Triarchic model of psychopathy characterizes this complex condition in terms of distinct phenotypic constructs of boldness, meanness, and disinhibition. The current study evaluated the coverage of these constructs provided by a well-established inventory for assessing psychopathy in adolescents, the Youth Psychopathic Traits Inventory (YPI). A consensus rating approach was used to identify YPI items relevant to each Triarchic model construct, and convergent and discriminant validity of the resulting YPI-Triarchic scales were examined in relation to criterion measures consisting of scores on other psychopathy measures and relevant personality trait variables (N = 618, M age = 18.8). The YPI-Triarchic scales showed good internal consistency and exhibited properties largely consistent with predictions based on the Triarchic model, aside from somewhat greater than expected covariance between boldness and other facet scales. Findings are discussed in terms of their implications for interpreting scores on the YPI and for investigating distinctive components of psychopathy in youth.

Only a limited number of medical disorders have been thoroughly studied in relation to ADHD, and knowledge is especially lacking for disorders that develop in older ages. This study aimed to map out the phenotypic and aetiologic associations between ADHD and a wide range of medical disorders across adulthood.

Full- and maternal half-siblings (N = 4,288,451 pairs), aged 18–81 years, were identified from Swedish Population Registers and linked to ICD-diagnoses from National Patient Registers. Logistic regression was used to estimate associations between ADHD and 35 medical disorders (8 disease groups) within-individuals, and across full- and half-siblings. Quantitative genetic modelling was performed to estimate genetic and environmental contributions to the associations with ADHD.

Adults with ADHD had increased risk for most medical disorders (34/35), showing the strongest associations with nervous system (OR = 3.27) and respiratory (OR = 2.49) disease groups. Significantly (P < 0.001) stronger associations were found between full-siblings than half-siblings for nervous system, respiratory, musculoskeletal and metabolic disease groups. Subsequent quantitative genetic modelling showed that these associations with ADHD were largely explained by shared genetic factors, with the exception for nervous system disorders.

Individuals with ADHD are at increased risk for a range of medical disorders, with long-term aspects into adult life. While numerous associations between ADHD and medical disorders were largely driven by genetic factors, others, such as nervous system and ageing disorders were mainly driven by individual-specific environmental factors. This mapping of aetiological sources of covariance can guide future research aiming to identify specific mechanisms that contribute to risk for medical disorders in ADHD

BACKGROUND: Emerging evidence suggests increased risk of several physical health conditions in people with ADHD. Only a few physical conditions have been thoroughly studied in relation to ADHD, and there is little knowledge on associations in older adults in particular. We aimed to investigate the phenotypic and aetiological associations between ADHD and a wide range of physical health conditions across adulthood.

METHODS: We did a register study in Sweden and identified full-sibling and maternal half-sibling pairs born between Jan 1, 1932, and Dec 31, 1995, through the Population and Multi-Generation Registers. We excluded individuals who died or emigrated before Jan 1, 2005, and included full-siblings who were not twins and did not have half-siblings. ICD diagnoses were obtained from the National Patient Register. We extracted ICD diagnoses for physical conditions, when participants were aged 18 years or older, from inpatient (recorded 1973-2013) and outpatient (recorded 2001-13) services. Diagnoses were regarded as lifetime presence or absence. Logistic regression models were used to estimate the associations between ADHD (exposure) and 35 physical conditions (outcomes) in individuals and across sibling pairs. Quantitative genetic modelling was used to estimate the extent to which genetic and environmental factors accounted for the associations with ADHD.

FINDINGS: 4 789 799 individuals were identified (2 449 146 [51%] men and 2 340 653 [49%] women), who formed 4 288 451 unique sibling pairs (3 819 207 full-sibling pairs and 469 244 maternal half-sibling pairs) and 1 841 303 family clusters (siblings, parents, cousins, spouses). The mean age at end of follow-up was 47 years (range 18-81; mean birth year 1966); ethnicity data were not available. Adults with ADHD had increased risk for most physical conditions (34 [97%] of 35) compared with adults without ADHD; the strongest associations were with nervous system disorders (eg, sleep disorders, epilepsy, dementia; odds ratios [ORs] 1·50-4·62) and respiratory diseases (eg, asthma, chronic obstructive pulmonary disease; ORs 2·42-3·24). Sex-stratified analyses showed similar patterns of results in men and women. Stronger cross-disorder associations were found between full-siblings than between half-siblings for nervous system, respiratory, musculoskeletal, and metabolic diseases (p<0·007). Quantitative genetic modelling showed that these associations were largely explained by shared genetic factors (60-69% of correlations), except for associations with nervous system disorders, which were mainly explained by non-shared environmental factors.

INTERPRETATION: This mapping of aetiological sources of cross-disorder overlap can guide future research aiming to identify specific mechanisms contributing to risk of physical conditions in people with ADHD, which could ultimately inform preventive and lifestyle intervention efforts. Our findings highlight the importance of assessing the presence of physical conditions in patients with ADHD.

FUNDING: Swedish Research Council; Swedish Brain Foundation; Swedish Research Council for Health, Working Life, and Welfare; Stockholm County Council; StratNeuro; EU Horizon 2020 research and innovation programme; National Institute of Mental Health.

I denna artikel vill vi sammanfatta kunskapsläget om den senaste forskningen om kopplingen mellan ADHD, livsstilsfaktorer och somatisk sjuklighet i vuxen ålder.

Under senare år har kunskapen ökat om sambanden mellan ADHD och ett flertal somatiska sjukdomstillstånd.

Denna insikt belyser vikten av grundliga somatiska hälso­undersökningar av patienter vid utredning för ADHD.

ADHD is currently classified as a neurodevelopmental disorder (NDD) and clustered together with Autism Spectrum Disorder and intellectual disabilities in the recently updated diagnostic manuals (DSM-5/ICD-11). There is, however, evidence for strong genetic overlap of ADHD with not only NDDs but also with internalizing and externalizing disorders, as well as with a general psychopathology-factor. These genetic findings challenge the accuracy of the current nosology of ADHD. In this study we therefore aimed to compare the strength of phenotypic, genetic and environmental correlations of ADHD with NDDs, internalizing and externalizing disorders, to explore if ADHD is more closely linked to one of these disorder domains. We further aimed to determine the etiological overlap between ADHD and the domains after accounting for a general psychopathology-factor. We identified full and maternal half siblings in the Swedish population and linked diagnostic data from the National Patient Register. Through structural equation modeling we fitted a confirmatory factor model, where one general factor loaded onto all disorders, and disorder clusters (NDD, internalizing, externalizing) each had a factor loading onto the disorders. We allowed ADHD to have loading from each of the cluster factors and the general factor. Initial findings showed similar magnitudes of genetic overlap of ADHD with NDDs (rg= 0.52–0.70) and internalizing disorders (rg= 0.58–0.68). Further analyses will be extended to include externalizing disorders, and to estimate etiological overlap after accounting for a general psychopathology-factor. Our findings may be informative for the nosology of ADHD as well as for increasing our understanding of the etiology of psychiatric disorders.

Background: A better understanding of the trajectories and economic burden of psychiatric and somatic disorders (multimorbidity) in ADHD from childhood to adulthood is important for guiding more targeted areas for treatment of ADHD and prevention of multimorbidity, and for forecasting demands on the medical infrastructure. This study aimed to investigate patterns of healthcare utilization and costs of multimorbidity across young adulthood in individuals with a childhood ADHD diagnosis, and additionally in individuals who continue to have ADHD-related contact with health services (persisters) and those who do not (remitters).

Methods: We prospectively followed a cohort (N = 445,790) born 1987-1990 from the ages of 18 to 26 years. Data on healthcare utilization were obtained from the Swedish National Patient Register (inpatient and outpatient care) and the Prescribed Drug Register (medication prescriptions).

Results: Mean annual costs per capita from multimorbidity was euro890 ($1,223) in individuals with a childhood ADHD diagnosis (persisters/remitters: euro1,060[$1,456]/euro609[$837]) and euro304 ($418) in individuals without. Costs were largely driven by inpatient hospital admissions, mainly from drug abuse and injuries. Healthcare utilization and costs of psychiatric and somatic disorders at 18 years was significantly higher in individuals with childhood ADHD compared to those without. These group differences remained stable or increased across young adulthood for most outcomes and were generally larger in women than in men. ADHD remitters continued to show significantly greater healthcare utilization and costs compared to individuals without childhood ADHD, although their profiles were not as severe as ADHD persisters.

Conclusions: Childhood ADHD has long-term associations with both psychiatric and somatic disorders. Findings demonstrate the individual and societal burden of ADHD in adulthood and highlight the importance of continued support from childhood-adolescent to adult health services and early prevention of multimorbidity. Findings also point to specific targets for intervention that may be effective, such as drug abuse and injuries.

There is scarcity of research investigating the validity of self-report of attention deficit hyperactivity disorder (ADHD) symptoms compared to other informants, such as parents. This study aimed to compare the predictive associations of ADHD symptoms rated by parents and their children across adolescence on a range of adverse socioeconomic and health outcomes in early adulthood. Parent- and self-rated ADHD symptoms were assessed in 2960 individuals in early (13-14 years) and late adolescence (16-17 years). Logistic regression analyses were used to compare the associations between parent- and self-rated ADHD symptoms at both time points and adverse life outcomes in young adulthood obtained from Swedish national registries. Both parent- and self-ratings of ADHD symptoms were associated with increased risk for adverse outcomes, although associations of parent-ratings were more often statistically significant and were generally stronger (OR = 1.12-1.49, p < 0.05) than self-ratings (OR = 1.07-1.17, p < 0.05). After controlling for the other informant, parent-ratings of ADHD symptoms in both early and late adolescence significantly predicted academic and occupational failure, criminal convictions and traffic-related injuries, while self-ratings of ADHD symptoms only in late adolescence predicted substance use disorder and academic failure. Our findings suggest that both parent- and self-ratings of ADHD symptoms in adolescence provides valuable information on risk of future adverse socioeconomic and health outcomes, however, self-ratings are not valuable once parent-ratings have been taken into account in predicting most outcomes. Thus, clinicians and researchers should prioritize parent-ratings over self-ratings.

BACKGROUND: Although attention-deficit hyperactivity disorder (ADHD) is classified as a neurodevelopmental disorder in the latest diagnostic manuals, it shows phenotypic and genetic associations of similar magnitudes across neurodevelopmental, externalising and internalising disorders.

AIMS: To investigate if ADHD is aetiologically more closely related to neurodevelopmental than externalising or internalising disorder clusters, after accounting for a general psychopathology factor.

METHOD: Full and maternal half-sibling pairs (N = 774 416), born between 1980 and 1995, were identified from the Swedish Medical Birth and Multi-Generation Registers, and ICD diagnoses were obtained from the Swedish National Patient Register. A higher-order confirmatory factor analytic model was fitted to examine associations between ADHD and a general psychopathology factor, as well as a neurodevelopmental, externalising and internalising subfactor. Quantitative genetic modelling was performed to estimate the extent to which genetic, shared and non-shared environmental effects influenced the associations with ADHD.

RESULTS: ADHD was significantly and strongly associated with all three factors (r = 0.67-0.75). However, after controlling for a general psychopathology factor, only the association between ADHD and the neurodevelopmental-specific factor remained moderately strong (r = 0.43, 95% CI = 0.42-0.45) and was almost entirely influenced by genetic effects. In contrast, the association between ADHD and the externalising-specific factor was smaller (r = 0.25, 95% CI = 0.24-0.27), and largely influenced by non-shared environmental effects. There remained no internalising-specific factor after accounting for a general factor.

CONCLUSIONS: Findings suggest that ADHD comorbidity is largely explained by genetically influenced general psychopathology, but the strong link between ADHD and other neurodevelopmental disorders is also substantially driven by unique genetic influences.

Emerging evidence suggests that ADHD is associated with increased risk for metabolic and cardiovascular (cardiometabolic) diseases. However, an understanding of the mechanisms underlying these associations is still limited. In this study we estimated the associations of polygenic scores (PGS) for ADHD with several cardiometabolic diseases and biomarkers. Furthermore, we investigated to what extent the PGS effect was influenced by direct and indirect genetic effects (i.e., shared familial effects). We derived ADHD-PGS in 50,768 individuals aged 18-90 years from the Dutch Lifelines Cohort study. Using generalised estimating equations, we estimated the association of PGS with cardiometabolic diseases, derived from self-report and several biomarkers measured during a physical examination. We additionally ran within-sibling PGS analyses, using fixed effects models, to disentangle direct effects of individuals' own ADHD genetic risk from confounding due to indirect genetic effects of relatives, as well as population stratification. We found that higher ADHD-PGS were statistically significantly associated with several cardiometabolic diseases (R-squared [R²] range = 0.03-0.50%) and biomarkers (related to inflammation, blood pressure, lipid metabolism, amongst others) (R² range = 0.01-0.16%) (P < 0.05). Adjustment for shared familial factors attenuated the associations between ADHD-PGS and cardiometabolic outcomes (on average 56% effect size reduction), and significant associations only remained for metabolic disease. Overall our findings suggest that increased genetic liability for ADHD confers a small but significant risk increase for cardiometabolic health outcomes in adulthood. These associations were observable in the general population, even in individuals without ADHD diagnosis, and were partly explained by familial factors shared among siblings.

Aims: To study associations between intellectual disability (ID) and sexual and violent offending among individuals subject to pre-trial forensic psychiatric assessment. To investigate sentences following pre-trial forensic psychiatric assessment in offenders with and without ID.

Methods: A population-based observational study using data from pre-trial forensic psychiatric assessments in Sweden (1997-2013), the Swedish National Crime Register and several other Swedish national registers. The study population consisted of 7450 offenders (87% men, 13% women) who were subject to forensic psychiatric assessment in 1997-2013, of whom 481 (6.5%) were clinically assessed as having ID.

Results: ID offenders were more likely than non-ID offenders to have a sexual crime as an index crime [26.2 v. 11.5%, adjusted odds ratio (OR) 2.7, 95% confidence interval (CI) 2.02-3.58] as well as previous convictions regarding sexual offending (10.4 v. 5.6%, adj OR 2.3, 95% CI 1.70-3.12). These associations were restricted to male offenders; sexual offending was uncommon among women. Comorbid attention-deficit hyperactivity disorder reduced the association between ID and sexual offending (adj OR 2.7 v. 3.1, p = 0.017), while comorbid autism spectrum disorder had no significant influence on the association (adj OR 2.7 v. 3.0, p = 0.059). Violent crime was equally common among ID and non-ID offenders. Offenders with ID were more likely than non-ID offenders to be sentenced to forensic psychiatric care or community sanctions and measures (such as probation, conditional sentences or fines) than to prison; however, 15% of individuals who received an ID diagnosis during the forensic psychiatric assessment were sentenced to prison. Previous criminal convictions, concurrent antisocial personality disorders and substance use disorders were associated with a higher probability of a prison sentence among offenders with ID.

Conclusions: Sexual crime is overrepresented among offenders with ID compared to offenders with other mental disorders than ID in forensic psychiatric contexts. ID offenders become subject to forensic psychiatric care and forensic psychiatric services need evidence-based treatment programmes for offenders with ID. In addition, there is a need for early intervention strategies suitable for disability services and special education schools, in order to address the complex needs of individuals with ID and prevent sexual and violent offending.

Background: Offenders with intellectual disability (ID) constitute a distinct subgroup of offenders with mental disorders. Regarding criminal recidivism, it is unclear whether or not offenders with ID in forensic psychiatric settings differ from offenders without ID. Factors associated with criminal recidivism among offenders with ID have been scarcely investigated.

Aim: To investigate the association between ID and criminal recidivism among offenders sentenced to forensic psychiatric care and to explore the impact of clinical, sociodemographic and offense variables.

Materials and methods: We conducted a retrospective cohort study based on Swedish nationwide registers. A total of 3,365 individuals being sentenced to forensic psychiatric care in Sweden in 1997-2013 were followed from the forensic psychiatric assessment until first reconviction, death, emigration, or 31 December 2013, whichever occurred first. Cox regression models compared rates of recidivism in individuals with and without ID. Impact of clinical, sociodemographic, and offense variables on risk of criminal recidivism was presented as hazard ratios (HRs) with 95% confidence intervals (CIs).

Results: Out of 3,365 offenders sentenced to forensic psychiatric care, 259 (7.7%) were diagnosed with ID. During follow-up (0-17 years, median 6 years), one third (n = 1,099) of the study population relapsed into criminality, giving a recidivism rate of 50.5 per 1,000 person-years. We observed an association between ID and a decreased risk of recidivism (HR 0.8, 95% CI 0.6-1.0, p = 0.063), although this reached statistical significance only for the subgroup of male offenders (HR 0.8, 95% CI 0.6-1.0, p = 0.040) and not females (HR 1.0, 95% CI 0.6-1.8). ID offenders with concurrent ADHD tended to have a higher rate of recidivism (73.9 per 1,000 person-years, HR 1.2, 95% CI 0.6-2.4) than ID offenders without ADHD (42.5 per 1,000 person-years, HR 0.8, 95% CI 0.6-1.1). Amongst ID offenders, concurrent autism spectrum disorder, young age or male sex were not associated with recidivism, while previous criminal convictions were strongly associated with recidivism.

Conclusion: A diagnosis of ID was associated with a lower risk of criminal recidivism among male offenders sentenced to forensic psychiatric care. The association between ADHD and recidivism among ID offenders highlights eligible focus areas in the management of offenders with ID.

Background: The current lack of knowledge about intellectual disability (ID) in forensic psychiatric contexts can compromise the legal certainty of these individuals during the medico-legal process. To address ambiguous results in previous literature, the aim of the current study was to estimate the prevalence of ID in a pre-trial forensic psychiatric settings. Moreover, as little is known about the characteristics of offenders with ID, we conducted a clinical characterization of individuals with and without ID being subject to forensic psychiatric assessment.

Methods: Using data from several Swedish national registers, we conducted a population-based retrospective observational study on 8,442 individuals being subject to pre-trial forensic psychiatric assessments in Sweden in 1997–2013. We performed univariate analyses to compare the characteristics of individuals with (n = 537) and without ID (n = 7,905).

Results: The prevalence of ID was 6.4% in the Swedish pre-trial forensic psychiatric context during the observational period. Compared with individuals without ID, individuals with ID were younger at the time of assessment, had a lower educational level, and had less frequently started families. ID was associated with lower frequency of diagnosed psychotic and bipolar disorders. However, a similar prescription rate of antipsychotics, and a comparable rate of previous inpatient care was observed among individuals with and without ID. Individuals with ID had more often been prescribed anti-libidinal treatments often used for treating sexual disorders, although did not present a higher prevalence of sexual disorder.

Conclusions: The prevalence of ID among pre-trial individuals being subject to forensic psychiatric assessment was more than twice as high as assumed in the general population. Our results suggest that individuals with ID received pharmacotherapy without clear indication. Remaining challenges in the clinical management of individuals with ID were indicated by the discrepancy between the occurrence of psychiatric diagnoses, pharmacological treatment patterns, and rates of inpatient care.

The association between alcohol use and internalizing symptoms during adolescence varies across studies, and the causes underlying this association remain unclear. The current study examines the relationship between symptoms of anxiety and depression and intoxication frequency in a sample of Swedish twins assessed longitudinally from ages 13-14 to 19-20. The objectives of the study were to assess the stability of genetic and environmental influences on each trait across adolescence; to investigate whether these traits share genetic and/or environmental liabilities; and to explore quantitative changes in the shared liability over time. We found that the magnitude of genetic influences on internalizing symptoms remained relatively stable across adolescence, while their impact on intoxication frequency was dynamic. Symptoms of anxiety and depression were influenced by unique environmental factors, while both shared and unique environmental factors influenced intoxication frequency. Genetic and environmental innovation and attenuation were observed for both traits. While no significant genetic correlation was observed between traits, unique environmental factors did contribute to a shared liability. This environmental correlation was positive and moderate (r(E)=0.41) in the early assessment, but decreased and changed direction at later waves (r(E)=-.04 to -.01). The genetic and environmental factors underlying internalizing symptoms and intoxication frequency appear to be developmentally dynamic. Early environmental factors contribute to the association between these traits, but this shared liability diminishes across adolescence.

A growing body of research has demonstrated the potential role for physical activity as an intervention across mental and other medical disorders. However, the association between physical activity and suicidal ideation, attempts, and deaths has not been systematically appraised in clinical samples. We conducted a PRISMA 2020-compliant systematic review searching MEDLINE, EMBASE, and PsycINFO for observational studies investigating the influence of physical activity on suicidal behaviour up to December 6, 2023. Of 116 eligible full-text studies, seven (n=141691) were included. Depression was the most frequently studied c mental condition (43%, k=3), followed by chronic pain as the most common other medical condition (29%, k=2). Two case-control studies examined suicide attempts and found an association between physical activity and a reduced frequency of such attempts. However, in studies examining suicidal ideation (k=3) or suicide deaths (k=2), no consistent associations with physical activity were observed. Overall, our systematic review found that physical activity may be linked to a lower frequency of suicide attempts in non-prospective studies involving individuals with mental disorders.

CONTEXT: It has been suggested that injuries and accidents are increased in females with congenital adrenal hyperplasia (CAH), but the prevalence is unclear.

OBJECTIVE: To study the prevalence of injuries and accidents in females and males with CAH.

DESIGN, SETTING, AND PARTICIPANTS: Patients with CAH (n = 714, all 21-hydroxylase deficiency) were compared with matched controls (n = 71,400). Data were derived by linking National Population-Based Registers.

MAIN OUTCOME MEASURES: Prevalence of injuries and accidents.

RESULTS: Mean age was 29.8 ± 18.4 years. Injuries were more prevalent in patients with CAH than in controls (RR 1.34, 95%CI 1.24-1.44), and this was found in both sexes (females: 1.43, 1.29-1.58; males: 1.25, 1.12-1.38). In the classical phenotype, the prevalence of injuries was higher, especially in females but not in the non-classic phenotype. In the genotype groups, injuries were mainly increased in females. Head injuries were increased in all patients with CAH and in the different phenotypes and were mainly driven by females. More patients with CAH born before the introduction of neonatal screening had had an injury compared to controls (1.48, 1.35-1.62), this was seen in both sexes. In patients with CAH born after the introduction of screening, the prevalence of injuries was overall increased (1.20, 1.07-1.35), and in females with CAH but not in males. Accidents showed a similar pattern to injuries in all comparisons.

CONCLUSIONS: Patients with CAH had an increased prevalence of both injuries and accidents, especially in females and in those born before the neonatal screening program. Patients with NC phenotype were hardly affected.