Link between Adolescent Pot Smoking and Psychosis Strengthens

Research presented at a Berlin psychiatric conference shows teenage cannabis use hastens onset of schizophrenia in vulnerable individuals

By R. Douglas Fields on October 20, 2017

•••••

Marijuana’s potentially detrimental impact on the developing brains of adolescents remains a key focus of research—particularly because of the possibility teenage users could go on to face a higher risk of psychosis.

New findings may fuel those worries. At the World Psychiatric Association’s World Congress in Berlin on October 9, Hannelore Ehrenreich of the Max Planck Institute of Experimental Medicine presented results of a study of 1,200 people with schizophrenia. The investigation analyzed a wide range of genetic and environmental risk factors for developing the debilitating mental illness. The results—being submitted for publication—show people who had consumed cannabis before age 18 developed schizophrenia approximately 10 years earlier than others. The higher the frequency of use, the data indicated, the earlier the age of schizophrenia onset. In her study neither alcohol use nor genetics predicted an earlier time of inception, but pot did. “Cannabis use during puberty is a major risk factor for schizophrenia,” Ehrenreich says.

Other studies, although not all, support the thrust of Ehrenreich’s findings. “There is no doubt,” concludes Robin Murray, a professor of psychiatry at King’s College London, that cannabis use in young people increases the risk of developing schizophrenia as an adult. Speaking at the Berlin conference, Murray—one of the first scientists to research pot’s link to the disorder—cited 10 studies that found a significant risk of young cannabis users developing psychosis. He also mentioned three other studies that identified a clear trend but had a sample size that was too small to reach statistical significance. “The more [cannabis] you take—and the higher the potency—the greater the risk,” he contends, warning this makes the increasingly potent new strains of marijuana especially concerning.

•••••


tags: drug abuse, drug use