Each year, one million people die of suicide. Among the different identified risk factors, genetic factors seem to be part of a multidimensional behavior, including psychiatric, psychosocial, biological factors and physical illness.

Family studies have provided evidence for familial transmission in suicide, confirmed in twin and adoption studies. At a molecular level, serotonin seems to be one of the key neurotransmitters implicated in suicidal behavior.

Therefore, genes coding for proteins involved in serotonergic neurotransmission have been extensively studied in case-control association studies on suicide. Major findings concern Tryptophan hydroxylase (TPH) gene, particularly in violent suicidal behavior.

Though they may seem contradictory, studies on Serotonin transporter (5-HTT), Monaomine oxidase (MAOA), Serotonin 2A and 2C receptors (5-HT2A and 5-HT2C) and Tyrosine hydroxylase (TH) genes are promising. In spite of those observations having some limitations,

it appears that genetic factors are a serious risk factor, besides environmental aspects of suicidal behavior.

About the Authors

Souery D, Oswald P, Linkowski P, Mendlewicz J. (2003) Molecular genetics in the analysis of suicide. Ann Med. 2003;35(3):191-6. Department of Psychiatry, University Clinics of Brussels, Erasme Hospital, Université Libre de Bruxelles, Belgium.