Genetics of suicide, from genes to behaviour

Suicide “is the result of an act deliberately initiated and performed by a person in the full knowledge or expectation of its fatal outcome”, it is one of the leading causes of death among young adults, every year about 1000000 people in the world die for suicide. Suicidal behavior can be explained by 43% by genetics, and the remaining 57% by environmental factors. Suicide is a complex, multifactorial phenomenon, with specific biological, psychological, and environmental risk factors, including psychiatric disorders (primarily depression), previous suicide attempt, psychosocial factors (stressful life events), personality traits (impulsivity and aggression), history of trauma and/or abuse, family history of both psychiatric disorders and suicidal behavior, substance and alcohol abuse and general medical conditions. Genetic, biochemical and "neuroimaging" studies impute a key role at the serotonergic system in the pathophysiology of suicidal behavior, although with results not always consistent. In the recent years an alternative approach to the issue of genetic modulation of suicide has focused on those that are specific endophenotypes of suicidal behavior. In particular, our research team analyzed a sample of psychiatric patients with previous suicide attempt and patients with a diagnosis of mood disorder without previous suicide attempt. The results show no direct correlation between genetic polymorphisms and suicidal behavior, but suggest the genetic modulation of personality traits, which were found to be risk factors for suicidal behavior. This approach, based on the study of association between candidate genes and specific endophenotypes show encouraging results for a better understanding of suicidal behavior.