The typical onset for MDD (82), panic disorder (89), and SUDs (90) is around early adulthood. We found the same when they were comorbid with OCD. It is possible that the detrimental psychological impact of a chronic and disabling OCD manifests around the stressful period of transition to adulthood in the form of depressive and panic disorders or as maladaptive coping with substance use. Personality disorders may reflect another vulnerability profile wherein OCD is triggered during a stressful transition to adulthood. In contrast, anxiety related comorbidities (GAD, PTSD, agoraphobia) decrease with a later AOO. As discussed earlier, these seem to emerge from shared developmental/temperamental vulnerabilities between OCD and anxiety disorders in youth. The interactive influences of childhood traumatic experiences, dissociative experiences, and vulnerabilities to anxiety are interesting in this regard (91, 92). Consistent with their emergence in young childhood and adolescence, comorbidity rates for ODD and BDD also fell with later AOO.
