Cannabis use triples teens’ psychosis risk

SMOKING cannabis just five times as a teenager can triple the risk of psychosis in later life.

Those who took the drug at a young age were more likely to develop schizophrenia and major depression with psychotic symptoms, a study found.

Researchers questioned more than 6,500 teenagers aged 15 and 16 on their cannabis use. They were monitored until the age of 30 and asked if they experienced symptoms of psychosis such as feeling like they were being followed or struggling to control their thoughts.

The results show teenagers who had tried cannabis five or more times in their youth were three times as likely to develop psychosis. This was the case even taking into account other substance use and the history of mental health problems in their parents.

Lead author Antti Mustonen said: ‘Our findings are in line with current views of heavy cannabis use, particularly when begun at an early age, being linked to an increased risk of psychosis.’

The Academy of Finland study was published in the British Journal of Psychiatry. The team included researchers from the University of Cambridge.