Study published in BMJ: Cannabis increases risks of psychotic symptoms

Tracy Parish

03 March, 2011

The editorial by Professor Degenhardt, Principal of Adolescent Health at Burnet, and Professor Wayne Hall from the University of Queensland was based on findings in prospective studies in Australia, Germany, the Netherlands, New Zealand and Sweden.

Professor Degenhardt said the evidence suggests that cannabis precipitates schizophrenia in vulnerable people and an increased risk of psychotic symptoms and disorders in the general population.

“It’s important we communicate this potential risk to the broader population and especially to cannabis users,” she said.

“We also know that extended cannabis use in adolescence predicts poorer educational outcomes, an increased risk of using other illicit drugs, an increased risk of depression and also poorer social relationships in early adulthood.”

The major challenge is to deter enough young people from using cannabis so that the prevalence of psychosis is reduced.

According to the Hall/Degenhardt editorial, the evidence on cannabis and psychosis has influenced the decision in the United Kingdom to retain criminal penalties for cannabis use, despite evidence that removing such penalties has little or no detectable effect on rates of use.

“An informed cannabis policy should be based not only on the harms caused by cannabis use, but also on the harms caused by social policies that attempt to discourage its use, such as criminal penalties for possession and use,” Professor Degenhardt observed.

Read the editorial on the British Medical Journal website.


Health Issue

Contact Details

For more information in relation to this news article, please contact:

Tracy Parish

Executive General Manager, Marketing and Communications




Subscribe to News

Subscribe to receive our latest news: