Association between violent suicidal behavior and the low activity allele of the serotonin transporter gene

There is compelling evidence that serotonin system dysfunction is associate d with certain behavioral disorders, such as suicidal behavior and impulsiv e aggression. A functional polymorphism in the promoter region of the serot onin transporter gene (5-HTTLPR) was recently identified and the presence o f the short allele found to be associated with a lower level of expression of the gene, lower levels of 5-HT uptake, suicidal behavior and anxiety-rel ated traits. We genotyped 51 West European Caucasians who had made violent suicide attempts and 139 controls of the same ethnic origin, with no histor y of suicidal behavior. The frequencies of the S allele and the SS genotype were significantly higher in the violent suicide attempters than in the co ntrols. The odds ratio for the SS genotype vs the LL genotype was 3.63 (95% CI (1.27-10.40)). This suggests that a change in expression of the gene en coding the 5-HT transporter may be involved in violent suicidal behavior.