WEDNESDAY, Feb. 9 (HealthDay News) -- Cannabis use is related to the earlier onset of psychotic symptoms among users of the drug compared to nonusers, according to a review published online Feb. 7 in the Archives of General Psychiatry.
Matthew Large, M.B.B.S., from the Prince of Wales Hospital in Sydney, Australia, and colleagues examined 83 published studies that reported the age of psychotic illness onset in users and nonusers of various substances. The association of cannabis, alcohol, and other psychoactive substances with the age of psychosis onset was analyzed.
The investigators found that the age of psychosis onset was two years younger for substance users than nonusers, using a broad definition of substance use. The age of psychosis onset was 2.70 years younger for cannabis users, compared to nonusers. Alcohol was not significantly associated with the earlier onset of psychosis.
"Even if the onset of psychosis were inevitable, an extra two or three years of psychosis-free functioning could allow many patients to achieve the important developmental milestones of late adolescence and early adulthood that could lower the long-term disability arising from psychotic disorders," the authors write.