Adult ADHD is associated with increased risk for suicide attempts, as indicated by investigations of population- and community-based cohorts. However, there is little data regarding suicide attempts in a clinical setting. To address this, we used a comprehensively phenotyped clinical adult ADHD (aADHD) cohort to assess to which extent comorbidity, psychosocial adversity, personality, and ADHD symptoms contribute to suicidal behavior in ADHD. Furthermore, we investigated a triallelic variation in…