Researchers have discovered a genetic mutation which increases aggression and impulsiveness in drinkers

Dr Roope Tikkanen, one of the researchers from Helsinki University Central Hospital in Finland, said that alcoholism, alcohol consumption and violence were closely related. 'People react quite differently to acute alcohol exposure,' he said. 'Most individuals become relaxed and talkative, while some - particularly persons who are introverted while sober - become expansively extroverted and aggressive.' Alcohol was found to increase the risk of impulsive violence among men born with a highly active version of a gene which produces the substance monoamine oxidase A, the researchers found. Unusually high levels of this chemical are linked to depression and hyperactivity. The mutation is less likely to trigger violence as people get older, the scientists said. The findings, which come from a study of 174 men with histories of violence and alcohol abuse, could pave the way for new drugs to stop drinkers becoming abusive.