Differentiation of obsessive-compulsive-, panic-, obsessive-compulsive personality-, and non-disordered individuals by variation in the promoter region of the serotonin transporter gene.

Past research investigating the role of the serotonin transporter gene in OCD has produced mixed findings. One possible reason for the mixed findings is comorbidity. In this study, non-comorbid OCD individuals were compared to non-disordered controls. A sample of panic disordered individuals was also compared to a non-disordered group. Finally, as an exploratory analysis, individuals were assessed for OCPD and their allelic frequencies were also compared to non-disordered individuals. Analyses revealed that there were higher frequencies of the s/s genotype among the OCD group when compared to non-disordered controls. There were no differences in allelic frequencies on the serotonin transporter gene between the panic disordered group, the OCPD group, and the non-disordered control group. This study found that non-comorbid OCD individuals tended to have a higher percentage of the homozygous short genotype than non-disordered individuals. The s/s genotype might serve as a contributory risk factor for OCD.