Este estudo avaliou 106 crianças e adolescents com TOC e 44 probandos controle. Estes probandos e seus 465 familiares de primeiro grau foram avaliados por entrevistadores treinados, usando entrevistas semi-estruturadas. Diagnósticos foram determinados pelo DSM-IV, pelo processo de estimativa de diagnóstico. Comparados aos "familiares controle", "familiares caso" tiveram risco significativamente aumentado para TOC (22.7% vs. 0.9%) e tiques (11.6% vs. 1.7%). Houve uma correlação significativa entre as idades de início do TOC nos probandos e seus familiares. Estes dados sugerem que o TOC de início precoce é um transtorno altamente familiar.

The current study examined 106 children and adolescents with OCD and 44 control probands. These probands and their 465 first-degree relatives were assessed by trained interviewers, using standardized semi-structured interviews. Diagnoses were assigned according to DSM-IV criteria, through the best-estimate process. Compared to control relatives, case relatives had higher age-corrected recurrence risks of OCD (22.7% vs. 0.9%) and tics (11.6% vs. 1.7%). There was a significant correlation between the ages of onset of OCD in probands and their affected relatives. These data suggest that childhood onset OCD is a highly familial disorder.