At the time of this study, interest in the role of the serotonin transporter gene regarding OCD was high. Research looking at the role of the gene showed mixed findings, potentially due to the presence of comorbid disorders.
This study by Dr. Joiner and his team aimed to investigate the role of the serotonin transporter gene by examining OCD compared to panic disorder and obsessive compulsive personality disorder (PTSD) to understand the scale of this gene’s role in the occurrence of OCD. A total of 153 participants took part in the study — 26 with OCD (some of whom also met criteria for OCPD), 19 with panic disorder, 36 with OCPD (some of whom also met criteria for OCD), and 89 healthy controls — whose cheek swabs were analyzed for the presence of serotonin transporter gene variants. People with OCD alone had higher frequencies of the s/s version (the homozygous short genotype) of the serotonin transporter gene than healthy controls, while the other groups had no difference in the amount of this version compared to the healthy controls. The results of this study provide evidence for an OCD marker that can contribute to the development of OCD; however, more research is needed, and the presence of this variant does not mean that this variant is a direct cause of OCD.
*Perez, M., Brown, J.S., Vrshek-Schallhorn, S., Johnson, F., & Joiner, T.E. (2006). Differentiation of obsessive-compulsive-, panic-, obsessive-compulsive personality-, and non-disordered individuals by variation in the promoter region of the serotonin transporter gene. Journal of Anxiety Disorders, 20, 794-806. doi:10.1016/j.janxdis.2005.09.001