title: Effects of MAOA-genotype, alcohol consumption, and aging on violent behavior.
abstract: BACKGROUND
  Environmental factors appear to interact with a functional polymorphism (MAOA-LPR) in the promoter region of the monoamine oxidase A gene (MAOA) in determining some forms of antisocial behavior. However, how MAOA-LPR modulates the effects of other factors such as alcohol consumption related to antisocial behavior is not completely understood.
  
  
  METHODS
  This study examines the conjunct effect of MAOA-LPR, alcohol consumption, and aging on the risk for violent behavior. Recidivism in severe impulsive violent behavior was assessed after 7 to 15 years in a sample of 174 Finnish alcoholic offenders, the majority of whom exhibited antisocial or borderline personality disorder or both, and featured impulsive temperament traits.
  
  
  RESULTS
  The risk for committing new acts of violence increased by 2.3% for each kilogram of increase in yearly mean alcohol consumption (p = 0.004) and decreased by 7.3% for every year among offenders carrying the high activity MAOA genotype. In contrast, alcohol consumption and aging failed to affect violent behavior in the low activity MAOA genotyped offenders. MAOA-LPR showed no main effect on the risk for recidivistic violence.
  
  
  CONCLUSIONS
  Violent offenders carrying the high activity MAOA genotype differ in several ways from carriers with the low activity MAOA risk allele previously associated with antisocial behavior. Finnish high activity MAOA genotyped risk alcoholics exhibiting antisocial behavior, high alcohol consumption, and abnormal alcohol-related impulsive and uncontrolled violence might represent an etiologically distinct alcohol dependence subtype.
authors.affiliation: Institute of Clinical Medicine, Department of Psychiatry, University of Helsinki, Helsinki, Finland. roope.tikkanen@helsinki.fi
authors.forename: Roope
authors.initials: R
authors.lastname: Tikkanen
authors.forename: Rickard L
authors.initials: RL
authors.lastname: Sjöberg
authors.forename: Francesca
authors.initials: F
authors.lastname: Ducci
authors.forename: David
authors.initials: D
authors.lastname: Goldman
authors.forename: Matti
authors.initials: M
authors.lastname: Holi
authors.forename: Jari
authors.initials: J
authors.lastname: Tiihonen
authors.forename: Matti
authors.initials: M
authors.lastname: Virkkunen
mesh_terms: D000328:Adult; D000374:Aggression / Q000187:drug effects*; D000375:Aging / Q000523:psychology*; D000428:Alcohol Drinking / Q000235:genetics / Q000523:psychology*; D005500:Follow-Up Studies; D006801:Humans; D007175:Impulsive Behavior / Q000139:chemically induced / Q000235:genetics*; D008297:Male; D008995:Monoamine Oxidase / Q000235:genetics*; D011110:Polymorphism, Genetic; D014754:Violence; D055815:Young Adult
chemical_list: D008995:Monoamine Oxidase