Serotonin transporter gene may be involved in short-term risk of subsequent suicide attempts.

Background: In the first year following a suicide attempt, patients are at high risk for reattempt and for completed suicide. We aim to determine the predictive value of two serotonin-related genes, the tryptophan hydroxylase (TPH) and serotonin transporter (5-HTTLPR) genes that have been involved in the susceptibility to suicidal behavior.

Methods: After a one-year follow-up study of 103 patients hospitalized after a suicide attempt, patients have been genotyped for both the A218C TPH and the functional S/L 5-HTTLPR polymorphisms.

Results: Patients who reattempted suicide during the follow-up period had significantly higher frequencies of the S allele and the SS genotype. The odds ratio for the SS genotype vs. the LL genotype was 6.5 (95% CI [1.18-35.84]). No difference was observed for TPH gene. Patients carrying the SS genotype were more impulsive. However, multivariate analysis suggested an independent effect of both the SS genotype and impulsivity on the risk of repeated suicide attempts.

Conclusions: These results suggest that the 5-HTTLPR SS genotype is associated with further suicide attempts among patients who have previously attempted suicide.