Serotonergic and dopaminergic system genes and their polymorphisms associated with suicidal behavior

Suicidal behavior is a complex, multifactorial phenomenon caused by the interaction of biological, psychological, social, and environmental factors. One of the key areas in the study of the biological basis of suicidal behavior is the study of genetic predisposition, which is confirmed by family, twin, and molecular genetic studies. A special role in the regulation of affective states and suicidal behavior is played by genes of the serotonergic (TPH1, TPH2, 5HTR2A, 5-HT1A, SLC6A4, 5-HT2C, MAOA) and dopaminergic (ANKK1, DRD2, COMT) systems. Serotonin is the main neurotransmitter involved in the regulation of mood, impulsivity, and stress response, and its imbalance is associated with depression and an increased risk of suicidal behavior. The dopaminergic system, in turn, affects motivation, cognitive processes, and stress response, and its dysfunction can contribute to the development of impulsivity and emotional instability, which also increases the risk of suicidal actions. Despite a significant number of studies aimed at studying the genetic predictors of suicidal behavior, their results remain contradictory. Differences in the sample, genotyping methods, and statistical processing of data, as well as the possible influence of epigenetic mechanisms, require a comprehensive analysis of the available data and further research into the molecular basis of suicide risk. The purpose of this review is to systematize data on genetic factors associated with suicidal behavior, based on an analysis of scientific publications over the past 12 years (2013–2024). The study of associations of gene polymorphisms can contribute to early diagnosis and the development of effective preventive intervention strategies.