A polymorphism in the promoter of the serotonin transporter gene is not associated with suicidal behavior

A 44 base pair deletion/insertion polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR) was examined in 124 German suicide attempters, who were consecutively hospitalized, and 185 German normal control subjects without a history of any DSM-IV axis I or II mental disorder. Both patients and control subjects were recruited from the same geographic area. There was no significant difference in allele or genotype frequency between patients and control subjects. There were also no differences when the patients were divided into several subgroups (suicide attempters with a violent method, and suicide attempters with a lifetime history of mood disorders, unipolar depression, personality disorders). These results suggest that the 5-HTTLPR polymorphism is unlikely to play a major role in the genetic susceptibility to suicide attempts. Conflicting results among the present and previous studies regarding an association between the polymorphism and suicidal behavior, however, suggest the possibility that there may be unidentified specific subtypes of suicidal behavior that are significantly associated with the polymorphism or, alternatively, simply reflect false-positive association results.