Obsessive-compulsive (OC) symptoms may begin at any point of the life span. Comorbid psychiatric disorders in OCD is more a rule than an exception and can contribute to the OCD-related burden.

The goal of this study is to understand the trajectory of comorbid disorders in OCD according to the first manifested psychiatric disorder and their impact in the clinical manifestation of OCD and.

1001 consecutive OCD outpatients from the Brazilian Obsessive-Compulsive Disorder Consortium were evaluated. Inclusion criterion: OCD as the main psychiatric diagnosis (DSM-IV). Exclusion criteria: comorbid schizophrenia and mental retardation. The instruments applied were: SCID-I; Y-BOCS; DY-BOCS, YGTSS (significant level =5%). To investigate the age at comorbidities onset Bayesian approach was performed. Those distributions contain all the information obtained by the data for the mean age at onset.

OCD patients that presented separation anxiety disorder (N=175, age of onset SAD 5.35) as first diagnosis had higher frequency of social phobia, simples phobia, generalized anxiety disorder and panic disorder (78.3%; p=0.05), somatoform disorders (13.1%; p=0.05) and post-traumatic stress disorder (30.3% p=0.003). OCD patients that presented ADHD (N=50, age of onset ADHD 6.42; age of onset OCD 13.08) as first diagnosis had higher frequency of substance abuse (16.0%; p=0.00001). OCD patients that presented tic disorders (N=44, age of onset tic disorder 6.86; age of onset OCD 16.18) as first diagnosis had higher frequency of OC spectrum disorders (50.0%; p=0.03).

First psychopathological manifestation in OCD patients is associated with distinct long-term trajectory of comorbid psychiatric disorders.