Background: Family studies of Obsessive-Compulsive (OCD) indicate there is substantial heterogeneity in the familiality of the disorder. This study was done to determine whether there are differences between familial and sporadic probands with early-onset OCD in obsessive-compulsive (OC) symptom categories and comorbid psychiatric diagnoses.
Methods: We ascertained 50 OCD probands ranging in age from 10 to 19 years with an onset of OC symptoms before age 15 years. All probands were directly assessed with semistructured diagnostic interviews; their first-degree and second-degree relatives were directly or indirectly assessed with similar diagnostic instruments. Descriptive data were compared in 33 familial and 17 sporadic OCD probands using logistic regression to control for age, gender, and age at onset of OC symptoms.
Results: Ordering compulsions were significantly more common in the familial OCD probands. Aberrant grooming behaviors were significantly more frequent in the familial subgroup with skin picking contributing significantly to that difference. Anxiety disorders other than OCD were also significantly more frequent in the familial subgroup with phobic disorders contributing significantly to that difference.
Conclusions: The results indicate that familial and sporadic forms of early-onset OCD may be differentiated by ordering compulsions, aberrant grooming behaviors, and anxiety disorders other than OCD.