Cannabis Use Causes Almost a Third of Schizophrenia Cases in Young Men: Study

Published: 5/6/2023, 3:59:41 PM EDT

A new study suggests that young men with cannabis addiction are more subject to the risk of developing schizophrenia.

The study, led by Danish researchers and published in the Psychological Medicine journal, found a strong link between schizophrenia and cannabis use disorder through analyzing health records of over 6 million people over 50 years. Experts estimate that nearly a third of schizophrenia cases in 21- to 30-year-old males were triggered by cannabis use disorder.

According to a 2021 National Institutes of Health survey, about 16.3 million Americans are estimated to have cannabis use disorder, also known as marijuana addiction.

The Danish study estimated that 30 percent of schizophrenia cases among men aged 21 to 30, and 15 percent of cases in 16- to 49-year-olds, could have been prevented by curbing cannabis addiction.

Schizophrenia is a serious mental illness where people appear to lose touch with reality. Symptoms can include delusions, hallucinations, slurred speech, trouble with thinking, and lack of motivation.

Dr. Nora Volkow, director of the National Institute on Drug Abuse, said, “The entanglement of substance use disorders and mental illnesses is a major public health issue, requiring urgent action and support for people who need it,”

“As access to potent cannabis products continues to expand, it is crucial that we also expand prevention, screening, and treatment for people who may experience mental illnesses associated with cannabis use.

As many countries and U.S. states have legalized cannabis in recent years, experts are warning that serious psychotic conditions could also increase.

“Increases in the legalisation of cannabis over the past few decades have made it one of the most frequently-used psychoactive substances in the world, while also decreasing the public’s perception of its harm,” said Dr. Carsten Hjorthøj, lead author of the study at the University of Copenhagen.

“This study adds to our growing understanding that cannabis use is not harmless, and that risks are not fixed at one point in time.”

The authors of the study have called for more research to understand why young men appeared more vulnerable to schizophrenia from heavy cannabis use compared with women.