Heavy drinking and impulsivity a vicious circle

Bouts of heavy drinking can increase male teens' levels of impulsive behaviour over time, including their propensity for heavier drinking. Early use of alcohol can weaken impulse control, leading to more drinking.

Researchers studied 503 boys in America who were assessed each year from first-grade until they were 20 years old, with another follow-up four to five years later. When they were teens, it was found that boys with moderate levels of impulsive behaviour showed a significant increase in impulsivity if they had engaged in heavy drinking the previous year, as opposed to those with low or high levels of impulsive behaviour.

Heavy alcohol use in adolescence may lead to alterations in brain structure and function that reduce behavioural (impulse) control, which could, in turn, promote further heavy drinking. The researchers chose boys because they tend to drink heavier than girls during adolescence, and adolescent boys generally exhibit less impulse control than adolescent girls.

The findings emphasise the need for prevention. Decreasing heavy drinking during adolescence may decrease impulsivity by preventing damage to crucial brain areas. The above findings also suggest that adolescents who stopped heavy drinking later 'rebounded' to lower levels of impulsivity. Therefore, decreasing drinking during adolescence could result in improved self-control at later ages.