Serotonin Transporters in Obsessive-Compulsive-Related Disorders

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.