Clinical and Genetic Risk Factors for Suicide under the Influence of Alcohol in a Polish Sample

Aims: Despite the large number of suicides that occur with intoxication, little is known about the unique predictors of suicide after alcohol consumption. The goal of this study was to examine clinical and genetic risk factors for alcohol-related suicide. Methods: Data on 162 suicide victims were obtained from post-mortem examinations, police and prosecution inquiries, autopsy protocols and available medical records. Four single nucleotide polymorphisms in the central serotonin system and the renin-angiotensin system related genes previously found to be associated with suicide, alcohol dependence or depression were genotyped. Results: The strongest predictor of suicide under the influence of alcohol was alcohol dependence (OR = 4.63). Those who did not drink alcohol before suicide were more likely to have a diagnosis of major depressive disorder in their medical record and more often had the TT genotype of the tryptophan hydroxylase 2 gene. Conclusions: Suicide under the influence of alcohol is strongly connected with alcohol dependence. The TPH2 gene may play an important role in suicide vulnerability especially in individuals who did not drink alcohol before suicide.