OBSESSIVE-COMPULSIVE DISORDER, RESPONSE TO SEROTONIN REUPTAKE INHIBITORS AND THE SEROTONIN TRANSPORTER GENE

Obsessive compulsive disorder (OCD) is a common illness, characterized by anxiety-provoking thoughts and the need to perform rituals. OCD is most commonly treated with a class of pharmacological agents known as serotonin reuptake inhibitors (SRIs), SRIs block the reuptake of sero tonin (5-HT) into the presynaptic neuron, a process mediated by the se rotonin transporter (5-HTT), The successful use of SRIs in OCD has led to the hypothesis that 5-HTT may play a pivotal role in the pathogene sis of OCD, We decided to study this hypothesis from a genetic perspec tive, because family and twin studies suggest that there is a strong g enetic component to OCD, In addition, the sequence of the gene for 5-H TT is available, and a 44-bp insertion/deletion polymorphism has been detected in the promoter region of the gene, There is evidence that th is polymorphism alters expression of the transporter protein, We typed 72 OCD patients and 72 matched controls, and found no statistically s ignificant difference between the two groups (chi(2) = 4.319, P= 0.115 , 2 d.f.), We observed however a trend towards increased homozygosity in the patient group, We also rated (retrospectively) the patients' cl inical responses to SRIs. No association was observed between these ra tings and the promoter region polymorphism in the serotonin transporte r gene. Given the pharmacological evidence favoring a role for 5-HTT i n OCD and SRI response, further genetic evaluation of the serotonin tr ansporter in OCD is indicated.