Posted on December 9, 2009

One in five Australian young people experience a cannabis use disorder, according to a University of Queensland (UQ) and Mater Hospital study published today in the American Journal of Drug and Alcohol Abuse. The findings also reveal the characteristics of those who are more likely to experience a cannabis use disorder.

Half of the 21-year-olds in the study reported having used cannabis in their lifetime, and 21 percent were classified as having a cannabis use disorder. Males were much more likely than females to have experienced cannabis abuse or dependence.

Children whose mothers frequently changed their marital status or who experienced sexual abuse at childhood were more likely to develop a cannabis use disorder by 21 years.

Those who showed aggressive or delinquent behavior at 14 years were more than twice as likely as other children to develop a cannabis use disorder by 21 years. Young adults who reported poor academic performance or had smoked a cigarette or consumed alcohol by 14 years were more likely to use and develop a cannabis disorder than others who had not.

Dr. Reza Hayatbakhsh, a researcher at the Queensland Alcohol Drug Research and Education Centre at UQ’s School of Population Health and lead author of the paper, believes that the study is a breakthrough for policy makers and health professionals.

“The majority of those who experience a cannabis disorder by 21 years of age are at moderate to high risk, based upon our data,” Dr. Hayatbakhsh said. “Policy makers could focus on addressing the health needs of young persons with aggressive or delinquent behavior, to limit the tobacco use of young people, and to the prevention of childhood sexual abuse.”

“Clinicians and health workers treating cannabis-related problems should consider the individual’s background as a possible contributor not only to their use of cannabis, but factors which may continue to limit the effectiveness of a treatment program,” Dr. Hayatbakhsh continued.

The study is based on the Mater-University Study of Pregnancy, Australia’s largest longitudinal study, which has tracked more than 8,000 mothers and their children over a 21-year period.