The Serotonin Transporter in Psychiatric Disorders

Abstract

<p>The neurotransmitter serotonin has been widely studied in psychiatric disorders. Indeed, the serotonergic hypothesis for mood disorders is the most widely accepted hypothesis. Most psychotropic medications, including SSRI antidepressants and atypical antipsychotics, act on the serotonergic system. The serotonergic system consists of serotonin, serotonin receptors, and the serotonin transporter. Within the serotonergic system, the serotonin transporter protein has been a focus of intense research. Researchers have tried to investigate the role of the serotonin transporter protein in a range of psychiatric disorders, from affective disorders to posttraumatic stress disorder (PTSD) to schizophrenia. The serotonin transporter protein has also been the focus of researchers trying to explore its role in variations in drug response. In this article, we review the existing evidence involving the serotonin transporter protein in the genesis of psychiatric disorders, variations in symptom presentation, and variations in drug response. We also briefly discuss some of the peculiarities of genetic research in psychiatric disorders and how they affect the outcome of research studies. </p> <h4>ABOUT THE AUTHORS</h4><p>Mohd A. Shamsi, MD, MSc, is Final-year Resident, Department of Psychiatry University of Missouri-Columbia. Sultana Jahan, MD, is Assistant Professor, Department of Psychiatry, University of Missouri-Columbia.</p> <p>Address correspondence to: Mohd A. Shamsi, MD; e-mail <a href="mailto:shamsim@health.missouri.edu">shamsim@health.missouri.edu</a>.</p> <p>Dr. Shamsi and Dr. Jahan have disclosed no relevant financial relationships.</p> <h4>EDUCATIONAL OBJECTIVES</h4> <ol><li>Describe the location of the serotonin transporter within the serotonin system and its role in the mechanism of antidepressant action.</li> <li>Demonstrate the basic terminology of genetics relevant to advances in psychiatry. </li><li>List the effects of a good study design and the importance of large sample sizes. </li></ol>