Effects of MAOA-genotype, alcohol consumption, and aging on violent behavior.
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.
Tikkanen
Roope
R
Institute of Clinical Medicine, Department of Psychiatry, University of Helsinki, Helsinki, Finland. roope.tikkanen@helsinki.fi
Sjöberg
Rickard L
RL
Ducci
Francesca
F
Goldman
David
D
Holi
Matti
M
Tiihonen
Jari
J
Virkkunen
Matti
M
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
D008995:Monoamine Oxidase