Serotonin-1D hypothesis of obsessive-compulsive disorder: An update

Support for the serotonin-1D (5-HT_1D) hypothesis of obsessive-compulsive disorder (OCD) and related conditions comes from a variety of sources. Some pharmacologic challenges with the 5-HT_1D agonist sumatriptan, and case reports in which prolonged administration of 5-HT _1D agonists was associated with a therapeutic effect, suggest that 5-HT_1D may play a role in obsessive-compulsive symptoms. Genetic studies have also found that polymorphism of the 5-HT_1D gene may be preferentially transmitted to those patients with OCD. However, taking into account that OCD is a heterogeneous syndrome, the 5-HT_1D hypothesis requires further investigation in order to disentangle the role of the 5-HT _1D receptor in this common and often severe disorder.