No association between non‐violent suicidal behavior and the serotonin transporter promoter polymorphism

Abstract
There is compelling evidence that suicidal behavior is associated with the dysfunction of the serotonin system. A functional polymorphism in the promoter region of the serotonin transporter gene (5‐HTTLPR) was recently identified and the presence of the short allele was associated with lower gene expression, lower 5‐HT uptake and violent suicidal behavior. Thus, we attempted to determine whether 5‐HTTLPR is also involved in the susceptibility to non‐violent suicidal behavior. We compared the genotype from 166 West European Caucasians who attempted suicide by a non‐violent mean with 139 controls with no history of suicidal behavior from the same ethnic origin. The frequencies of the S allele and the SS genotype in the sample who attempted non‐violent suicide were not statistically different to those in the controls. Thus, the genetically altered expression of the 5‐HT transporter might be associated with more severe or violent suicidal behavior, but not with non‐violent suicidal behavior.