Serotonin-1D Hypothesis of Obsessive-Compulsive Disorder: An Update

Support for the serotonin-1D (5-HT_1D) hypothesis of obsessive-compulsive disorder (OCD) andrelated conditions comes from a variety of sources. Some pharmacologic challenges with the 5-HT_1D agonistsumatriptan, and case reports in which prolonged administration of 5-HT_1D agonists was associatedwith a therapeutic effect, suggest that 5-HT_1D may play a role in obsessive-compulsive symptoms. Geneticstudies have also found that polymorphism of the 5-HT_1D gene may be preferentially transmittedto those patients with OCD. However, taking into account that OCD is a heterogeneous syndrome, the5-HT_1D hypothesis requires further investigation in order to disentangle the role of the 5-HT_1D receptor inthis common and often severe disorder.