Objective: Obsessive-compulsive disorder (OCD) is a clinically heterogeneous disorder with a bimodal age at onset and range of treatment outcomes. This study attempted to ascertain the importance of the age at OCD symptom onset for a better phenotypic precision. Therefore, the authors compared adult OCD patients with an early symptom onset to OCD patients with a later symptom onset.
Method: Forty-two adult outpatients with OCD were evaluated with semistructured interviews: 21 with symptom onset before the age of 10 (early-onset group) and 21 with symptom onset after the age of 17 (late-onset group).
Results: Early onset was associated with higher scores on the Yale-Brown Obsessive Compulsive Scale, higher frequencies of tic-like compulsions, higher frequency of sensory phenomena, and a higher rate of comorbid tic disorders. The early-onset group also responded less well to treatment with clomipramine and selective serotonin reuptake inhibitors.
Conclusions: The results indicate that age at onset may be an important factor in subtyping OCD and that the phenotypic differences found were not restricted to childhood.