Marijuana Use Linked to Increase in Psychotic Disorders
Psychiatric Times CARDIFF, Wales, July 27 -- Marijuana users face a risk of psychotic illness that increases with the frequency of exposure, results of a systematic review suggest. Individuals who reported any use of cannabis had a 41% greater risk of psychotic illness than people who had never used it, investigators here reported in the July 28 issue of The Lancet. And risk increased with use -- the most frequent users had a psychosis risk double that of never-users. "We conclude that there is now sufficient evidence to warn young people that using cannabis could increase their risk of developing a psychotic illness later in life," concluded Stanley Zammit, Ph.D., of Cardiff University, and colleagues. Evidence of an adverse effect of cannabis on affect is less compelling, they added. Marijuana, or cannabis -- the parent plant -- is the most commonly used illegal substance in most countries, the authors noted. About 20% of young people report using the hallucinogen at least