Catechol-o-methyltransferase gene modulation on suicidal behavior and personality traits: review, meta-analysis and association study.

Suicide is one of the leading causes of death among young adults. Both genetic and personality factors plausibly have a role on suicidal behavior. We focused on the catechol-O-methyltransferase gene (COMT) and we performed: a review of studies investigating the association between COMT and both suicidal behavior and personality; a meta-analysis of studies investigating the association between suicidal behavior and COMT rs4680 polymorphism; an association study investigating the link between seven COMT polymorphisms (rs737865, rs5844402, rs5993883, rs4680, rs4633, rs165599 and rs9332377) and both personality traits and suicidal behavior. For the review and the meta-analysis we performed an electronic search to identify studies focused on the association between COMT and both suicidal behavior and personality. The sample of the association study was composed of three groups: 289 German healthy controls, 111 German suicide attempters and 70 Italian mood disorder patients. From the review, the meta-analysis and the association study no relationship emerged between COMT and suicidal behavior. Nevertheless, from both review and association study several links were found between COMT and personality traits. In particular, in the association study we found a significant correlation between rs4633 and Reward Dependence (Temperament and Character Inventory). As secondary results we found an association between rs737865 and Angry Reaction (State-Trait Anger Expression Inventory) and between rs9332377 and Irritability (Questionnaire for Measuring Factors of Aggression). Our findings suggested that COMT variants may not be directly implicated in suicidal behavior, however evidence of a COMT role in the modulation of personality traits has been found.