Loneliness is a common experience in populations experiencing mental health problems. Associations with symptoms of psychopathology are prevalent, but little is known about the diversity of symptom profiles in people suffering from prolonged and distressing loneliness. The current study sought to investigate the existence of subgroups of loneliness and common forms of psychopathology in a sample of adults (n = 332) seeking treatment for their loneliness. Using latent profile analysis, five profiles were identified and differences in demographic factors were investigated. The profiles differed mainly in the severity of symptoms of depression, worry, and social anxiety, with the largest profile exhibiting minimal-to-mild symptoms (n = 109) across these indicators. The second largest group was characterized primarily by high ratings of social anxiety (n = 90). Overall, three of the five profiles, encompassing roughly half of the sample, scored at a clinical level on mental health symptom measures. Age was inversely related to symptom severity among the profiles, indicating that the older subgroups of the sample exhibited milder symptoms, particularly on social anxiety. The results provide insight into the heterogeneity of the clinical symptoms of people suffering from loneliness and add important knowledge that could help inform how to best intervene to help this population.

Loneliness has been described as a common source of discomfort based on a subjective discrepancy between the actual and desired social situation. For some people this feeling may become a sustained state that is associated with a wide range of psychiatric and psychosocial problems. While there are few existing treatment protocols, interventions based on cognitive behavioral therapy (CBT) have shown positive effects. The current study investigated the efficacy of an 8-week internet-based treatment containing CBT components aimed at reducing feelings of loneliness. Seventy-three participants were recruited from the general public and randomly allocated to treatment or a wait-list control condition. Participants were assessed with standardized self-report measures of loneliness, depression, social anxiety, worry, and quality of life at pretreatment and posttreatment. Robust linear regression analysis of all randomized participants showed significant treatment effects on the primary outcome measure of loneliness (between group Cohens d = 0.77), and on secondary outcomes measuring quality of life and social anxiety relative to control at postassessment. The results suggest the potential utility of internet-based CBT in alleviating loneliness but more research on the long-term effects and the mechanisms underlying the effects is needed.

The current study sought to investigate the long-term effects of an internet-administered programme based on CBT principles for which the initial efficacy has been reported in Kall, Jagholm, et al. (In press). Seventy-three participants who were recruited on the basis of experiencing frequent and prolonged loneliness were contacted to complete questionnaires measuring loneliness, quality of life, and symptoms of psychopathology two years after the conclusion of the initial treatment period. Additional items regarding use of the treatment techniques and strategies contained in the programme during the follow-up period was included. In total, 44 participants provided data for the loneliness measure at follow-up. The outcome data were analyzed with a piecewise mixed effects model to provide estimates of change for the continuous measures. Linear multiple regression analysis was used to investigate the relationship between use of treatment techniques and reliable change on the primary outcome measure. The results showed decreases in loneliness during the follow-up period for the sample as a whole. Additionally, an increase in quality of life and a decrease in social anxiety were noted, but no significant changes of depressive symptoms or generalized anxiety. Effect sizes for the observed changes from baseline to follow-up were in the moderate to large range for all measures. Reported use of the treatment techniques was not significantly related to reliable change in loneliness after the two-year period. In conclusion, the results of the study support the utility of internet-based CBT targeting loneliness and indicate that the benefits from the intervention can be enduring.

Introduction: Chronic loneliness has been linked to many adverse outcomes, including mental health problems. Psychological treatment of loneliness can be effective, but the evidence base is limited. Objective: To investigate the efficacy of 2 internet-based interventions based on cognitive behavioral therapy (ICBT) and interpersonal psychotherapy (IIPT) relative to a wait-list control group and each other. Methods: A total of 170 participants were recruited and randomized to either 9 weeks of ICBT (n = 68), IIPT (n = 68), or a wait-list condition (n = 34). The primary outcome was loneliness, measured using the UCLA Loneliness Scale before, during, and after treatment. Secondary measures of psychiatric disorders and quality of life were administered before and after treatment. Follow-up was conducted 4 months after the treatment had ended. Primary outcome data were analyzed using growth curve modeling. Secondary outcomes were analyzed using robust regression models. The trial was preregistered (ClinicalTrials.gov ID: NCT03807154). Results: The ICBT condition had a significantly greater impact on loneliness compared to the wait-list and IIPT conditions. Effect sizes were moderate to large (Cohen d = 0.71) compared to the wait-list and moderate (d = 0.53) compared to IIPT. The IIPT condition did not differ significantly from the wait-list. Both active treatments led to significant increases in quality of life. Only the ICBT group had significantly lower symptoms of depression and generalized anxiety compared to the wait-list group. Treatment gains were maintained but not improved at follow-up. Conclusions: ICBT can be an efficacious option for alleviating loneliness. The IIPT intervention was not as effective.