All subjects were assessed using the Structured Clinical Interview for DSM Axis I Disorders (SCID-I) (35). Subjects with a diagnosis of schizophrenia, schizoaffective disorder, autistic disorder, pervasive developmental disorder not otherwise specified, or intellectual disability were excluded from the present study. Other diagnostic criteria included: onset of symptoms prior to age 18 years; no previously diagnosed neurological disorder or OCD occurring exclusively in the context of depression; no known history of OCD in first degree relatives. Final diagnostic status was assigned based on the consensus of an experienced interviewer and a psychiatrist or psychologist after independent review and administration of the SCID. We prioritized the study of simplex OCD trios to increase the likelihood of detecting de novo sequence and structural variants. Available phenotype information, including gender and parental age, is included in Table S1.
