BACKGROUND Increasing use of cardiac implantable electronic devices (CIEDs) has raised concerns about psychological distress in young adults. We evaluated the risk of incident mental disorders after CIED implantation.

METHODS Using the Korean National Health Insurance database, we identified individuals aged 20 to 39 years who underwent health checkups in 2009 to 2012. Those receiving a new CIED within 4 years were included, and controls were selected by 1:5 matching for age, sex, and index year. The primary outcome was a composite of newly diagnosed mental disorders (mood disorders and anxiety/stress-related/somatoform disorders), and secondary outcomes were the individual components.

RESULTS There were 569 CIED recipients (209 pacemakers, 360 implantable cardioverter-defibrillators) and 2821 matched controls analyzed. Over a median follow-up of 5.3 years, both the pacemaker and implantable cardioverter-defibrillator implantations were associated with a significantly higher risk of the primary outcome compared with no device (hazard ratio [HR], 1.63 [95% CI, 1.20-2.21] and HR, 1.80 [95% CI, 1.39-2.35], respectively). In head-to-head analyses, the risk of the primary outcome did not differ significantly between implantable cardioverter-defibrillator and pacemaker recipients (adjusted HR, 1.09 [95% CI, 0.75-1.59]). Risks of secondary outcomes were also increased in both device groups. CIED recipients had a 1.95-fold higher risk of mental disorders within 2 years postimplantation (95% CI, 1.45-2.62), and this elevated risk persisted beyond 2 years (HR, 1.54 [95% CI, 1.13-2.11]).

CONCLUSIONS Among young individuals, both pacemaker and implantable cardioverter-defibrillator implantations were associated with increased risks of mental disorders, supporting proactive psychological screening and interventions.