Functional polymorphism in the serotonin transporter promoter at the SLC6A4 locus and mood disorders

Background: Heils et al found a functional polymorphism in the transcriptional control region upstream of the serotonin transporter gene at the SLC6A4 locus. The transcriptional promoter activity of the short (s) form was less than twice that of the long (I) form of the serotonin transporter promoter gene. In addition, they found individuals with the s form with associated neurotic characteristics (e.g., anxiety, anger hostility, and depression). The purpose of this study was to determine whether or not there is an association between this functional polymorphism and mood disorders. Methods: The l/s polymorphism was studied in 80 patients with mood disorders and 92 control subjects. Results: There was statistically no difference between mood disorders and healthy controls in either the genotype or the allele frequency. There was statistically no difference between the genotype and subdiagnosis, family history, single/recurrent episodes of depressive disorders, suicide attempts, or the mean age of onset. Conclusions: Our results suggest there is no association between the l/s polymorphism of the serotonin transporter gene and mood disorders. (C) 1998 Society of Biological Psychiatry.