Family and twin studies point towards a partial heritability of suicidal behavior.
We investigated the role of a comprehensive set of serotonergic candidate genes in
this behavior. Their selection was driven by results from post mortem and genetic
studies. 150 suicide attempters with various psychiatric disorders were compared with
volunteers which were randomly selected from the general population. 320 healthy control
subjects without relevant somatic and with no psychiatric disorder were included.
All subjects were administered standard psychiatric interviews including SCID as well
as self-report questionnaires for anger-related traits. The distribution of genetic
polymorphisms in the ABCG1, TPH, 5-HT1B, 5-HT2A, SERT, and MAOB genes was examined.
For anger-related traits, a multivariate effect of the A218 SNP in the TPH gene and
an interaction effect for genotype and diagnosis was observed in healthy volunteers
and suicide attempters after controlling for age and educational level. A meta-analysis
provides strong evidence for an association of suicide-related behavior with the A218
SNP in the TPH gene in Caucasians.