Teenagers who use cannabis could face an increased risk of psychosis in later life, according to experts.
Researchers studied data for more than 1900 people who were aged 14 to 24 at the start of the study.
The link between cannabis and psychotic symptoms was analysed by assessing the group of people three years later and then eight years later.
The study found that people who used cannabis at the start of the study and continued to do so faced an increased risk in psychotic symptoms.
Meanwhile, those who weren’t cannabis users at first but went on to become so also had a higher risk of psychotic experiences later in life.
Cannabis Christmas tree found in Germany
The findings, published in the British Medical Journal (BMJ), revealed: “Cannabis use is a risk factor for the development of incident psychotic symptoms.
“Continued cannabis use might increase the risk for psychotic disorder by impacting on the persistence of symptoms.”
Professor of psychiatric research at the Institute of Psychiatry Sir Robin Murray said: “This study adds incremental information to the already fairly solid evidence that continued use of cannabis increases risk of psychotic symptoms and psychotic illness.
“The study is one of 10 prospective studies all pointing in this same direction.
“It adds new information by showing that it is those who show psychotic symptoms within a few years of initiating cannabis use who are especially likely to develop persistent psychotic symptoms if they persist in their use of cannabis.
“In short, this study adds a further brick to the wall of evidence showing that use of traditional cannabis is a contributory cause of psychoses like schizophrenia.”
