Background – Congenital heart disease (CHD) is a known risk factor for cardiac events, but its role in recurrent events among patients receiving psychotropic medications remains unclear. This study examines the impact of CHD on the risk of recurrent cardiac events in patients treated with psychotropic medications.

Methods – This nationwide nested case–control study used Swedish register data from 2006 to 2018 and included individuals aged 5–30 years who were treated with psychotropic medications (attention-deficit hyperactivity disorder medications, antihistamines, antidepressants, anxiolytics, antipsychotics, and hypnotics) and experienced at least one cardiac event (e.g., cardiac arrest, arrhythmia, or syncope). Cases were individuals with recurrent cardiac events (≥2), while controls had a single event. The association between CHD and recurrent cardiac events was assessed by estimating adjusted odds ratios (AORs), controlling for sex, age, and psychotropic polypharmacy (≥2 medications).

Results – A total of 23, 504 individuals receiving psychotropic medical treatment experienced at least one cardiac event, of whom 2, 409 (10.25%) had recurrent events. The median age was 20 years (IQR 17–24) for cases and 22 years (IQR 18–26) for controls. Most cases were female (70%). Both overall CHD and severe CHD were associated with a higher risk of recurrent cardiac events compared with patients without CHD (AOR 1.82; 95% CI 1.35–2.47 and AOR 1.77; 95% CI 1.29–2.42, respectively). Among patients with CHD, male sex, age 15–30 years, and absence of psychotropic polypharmacy were associated with a lower risk of recurrence.

Conclusion – CHD is an independent risk factor for recurrent cardiac events among individuals treated with psychotropic medicines. Lower-risk factors included male sex, older age group, and absence of psychotropic polypharmacy.