Differentiation of Obsessive-Compulsive, Anxiety Disordered and Non-Disordered Individuals by Variation in the Promoter Region of the Serotonin Transporter Gene

Obsessive-Compulsive Disorder (OCD) is a severe and debilitating anxiety disorder with relatively little known about its etiology. The serotonin-transporter gene is one likely place to start investigating the genotypes associated with OCD, given the efficacy of serotonin re-uptake inhibitors for treating OCD. It was predicted that individuals with OCD would have higher frequencies of the s/s allele when compared to non-disordered individuals. The allelic frequency of the OCD group was also compared to an anxiety group consisting of mostly panic disordered individuals. As an exploratory analysis, individuals were also assessed for Obsessive-Compulsive Personality Disorder (OCPD) and their allelic frequencies were also compared to non-disordered individuals. In total there were 198 individuals genotyped, of which 30 had OCD with no other comorbidity, 26 had an anxiety disorder other than OCD, and 17 had OCPD. Consistent with the hypothesis, analyses revealed that there were higher frequencies of the s/s allele among OCD individuals when compared to non-disordered controls. There were no differences in allelic frequencies between the OCD group and the Anxiety disordered group. Finally, there were no differences in allelic frequencies on the serotonin transporter gene between the OCPD group and the non-disordered control group.