Study: Little damage from marijuana

United Press International

New York - In a preliminary study, U.S. researchers failed to find damage to the developing adolescent brain had occurred in those who had used marijuana moderately.

Lynn DeLisi and colleagues from the Nathan S. Kline Institute for Psychiatric Research and New York University School of Medicine used diffusion tensor imaging to scan the brain of 10 young people who had smoked cannabis during adolescence.

The participants were between 17 and 30 years old, and they said they had smoked at least two to three times a week for one or more years during adolescence and had no personal or family history of mental-health problems.

The study subjects were matched for sex, age and social class of parents with 10 controls who had not smoked marijuana regularly as teenagers.

DeLisi and colleagues found no significant differences in brain integrity and brain volume between cannabis smokers and non-smokers, but the study authors warn more research is necessary, both in a larger group of people and to see the effects of heavier use.

The findings are published in Harm Reduction Journal.