Psychotic symptoms more likely with cannabis
Using marijuana in adolescence and early adulthood increases the likelihood of psychotic symptoms in later life, a new study suggests. The risk of developing these symptoms is “moderate”, say researchers, though is higher in people with a pre-disposition to psychosis.
A team led by Jim van Os of the University of Maastricht in the Netherlands followed 2437 people aged between 14 and 24. After four years, 21% of cannabis users had experienced psychotic symptoms compared with 15% of non-users. And the more a participant used cannabis, the more likely they were to develop symptoms.
Family history
The risk appears greatest for those with a predisposition to psychosis, as evidenced by mild signs of psychosis at the outset of the study.