OBJECTIVES: We examined the associations of lifetime and current histories of psychiatric disorders and of suicidal thoughts and behaviors with childhood-onset epilepsies in a community-based cohort of young adults. METHODS: Cases were neurotypical (normal neurologic, cognitive, and imaging examinations and no evidence of a brain insult responsible for the epilepsy) young adults with childhood-onset epilepsy followed since the onset of their epilepsy approximately 15 years earlier and recruited as part of a community-based study. They were compared to two different control groups: siblings and external controls from the National Comorbidity Survey-Replication (NCS-R). The Diagnostic Interview Survey assessed lifetime and current Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) diagnoses of mood disorders and anxiety disorders. Suicidal thoughts and suicide attempt were assessed using the Diagnostic Interview Survey for Children-IV and the Diagnostic Interview Survey (DIS-IV). RESULTS: Two hundred fifty-seven cases and 134 sibling controls participated in the DIS-IV portion of the young adult assessment. Comparing cases both to their sibling controls and to the controls drawn from the NCS-R, we did not find any evidence to suggest a higher prevalence of lifetime and current mood or anxiety disorders, suicidal thoughts, and suicide attempt in young adults with childhood-onset epilepsies. SIGNIFICANCE: Our findings from a community-based sample of neurotypical young adults do not suggest a substantial or lasting association between childhood epilepsy and psychiatric disorders and suicidal behavior.