TUESDAY, Jan. 26, 2010 (HealthDay News) -- Cigarette smoking, but not behavioral problems, independently and consistently predicted the use of marijuana by adolescents in a new study.
The finding came from a study of more than 1,600 Dutch youngsters who were assessed at ages 10 to 12 and again at ages 12 to 15 and 15 to 18.
The results showed that the association between what the researchers called externalizing behavior problems -- conduct, attention deficit/hyperactivity and opposition -- and marijuana use was inconsistent. However, cigarette smoking at an early age was found to predict future marijuana use.
The findings, published in the January issue of the Journal of the American Academy of Child and Adolescent Psychiatry, challenge the widespread view that behavioral problems directly predict marijuana use.
"Early onset of cigarette smoking is a powerful predictor of later cannabis initiation, independent of preceding externalizing behavior problems," the researchers wrote. "Although externalizing behavior problems are important as a starting point for substance use trajectories, early onset smoking should be identified as an important marker of cannabis use risk."
The U.S. National Institute on Drug Abuse has more about marijuana.