ABCB1 gene polymorphisms and violent suicide attempt among survivors

Those suicide attempters that choose violent methods dramatically diminish the possibility of survival. Completed suicide using violent means, which is common among first-time suicide attempters, was recently found to be more likely among T allele carriers in the three most common ABCB1 SNPs, encoding for P-gp. Thus, this study examined, for the first time, whether these ABCB1 SNPs were associated with the use of violent means among survivors of a suicide attempt.

Suicide attempters (n = 578, 87.4% women; of whom 16.6% committed a violent intent) were genotyped for exonic SNPs in the ABCB1 (C1236T, G2677T/A, C3435T). The relations of the three genotypes and of the TTT haplotype with the use of a violent suicide method were evaluated separately. The impact of confounds on these variables was controlled.

A higher frequency (p = 0.02) of suicide attempters using violent methods was found among those carrying the ABCB1 haplotype (1236TT-2677TT-3435TT). Since gender and number of previous suicide attempts were identified as confounds, the relation was tested in the subset of women who were first-time attempters or second- and more-time attempters. The ABCB1 haplotype increased the risk more than three times in those women attempting a violent suicide for the first time (OR = 3.6; CI95%: 1.08-12.09; p = 0.04).

The ABCB1 haplotype (1236TT-2677TT-3435TT) was related to the use of a violent suicide attempt method. Genotyping for these three ABCB1 SNPs may be helpful to detect people at risk of first suicide intents using violent methods.