Evidence suggests that the symptoms of obsessive-compulsive disorder (OCD) arise from dysfunction of both the serotonergic and dopaminergic neurotransmitter systems. These two neurotransmitter systems are presumed to play a key modulatory role at the limbic-motor interface of the fronto-subcortical circuitry. However, in vivo knowledge linking the serotonergic and dopaminergic systems to OCD and OCD-related disorders is limited. In the current protocol, we plan to use PET to image the serotonin transporter (SERT) within the new radioligand \[11C\]DASB, in order to delineate regional abnormalities in SERT binding in drug-naive or drug-free OCD patients in comparison to healthy volunteers. In addition, we plan to examine the relationship between the regional PET measures of SERT and clinical severity measures of OCD. The goal of the present study is, thus, to further our understanding of the role of the serotonergic system in the pathophysiology of OCD.
* INCLUSION CRITERIA: Patients and Controls: Age: 18-65. Patients- DSM-IV criteria for OCD. Controls- not required Patients and Controls: Good health, with absence of serious medical illnesses, such as congestive heart failure, diabetes, kidney failure, epilepsy or cancer. EXCLUSION CRITERIA: Healthy Subjects: History or current DSM-IV Axis I diagnostic criteria. Patients and Controls: Current diagnosis of major depressive disorder. Patients and Controls: Psychotropic medications, including SSRIs and antipsychotic medications. Drug free period must be greater than 4 weeks. Patients and Controls: Claustrophobia Patients and Controls: Pregnancy. Women with child bearing potential. Patients and Controls: Prior participation in other research protocols within the past year such that a radiation exposure together with the present study would exceed the annual limits. Patients and Controls: Any condition that increases risk for MRI (e.g., pacemaker, metallic foreign body in the eye, etc.)