AMSTERDAM, Netherlands, Feb. 1 (UPI) -- A Dutch study on the effects of marijuana use on teenagers suggests a connection with aggressive behavior.
The BBC reports researchers at the Trimbos Institute in the Netherlands found 17 percent of the 5,551 12 to 16-year-olds questioned had used marijuana within the past year. The study found the higher the frequency and amount of marijuana use, the more aggressive behavior the teenager showed.
A recent study by the British Journal of Psychiatry found similar results.
A 2005 report by the Schools Health Education Unit in Britain found 25 percent of 14- and 15-year-olds smoked pot.
The studies found no evidence backing up claims made in past research linking marijuana use to emotional problems like depression.
Harald Wychgel, author of the Dutch study, said aggressive behavior and poor school grades are exacerbated in countries with more stringent drug laws.
Marijuana is regulated but not illegal in the Netherlands.
Paul Corry, spokesman for Rethink, a mental health group, said there isn't enough data to know whether marijuana leads to aggression, or if kids living in environments that promote aggression are more prone to smoke marijuana.