According to a new study pubished in the British Journal of Psychiatry, teenage cannabis users are more likely to suffer psychotic symptoms that raise the risk of full-blown mental illness in later life.
Dr Jouko Miettunen led the research at the University of Oulu in Finland. In the largest study of its kind more than 6,000 adolescent drug-takers aged 15 and 16 were interviewed and reported experiencing at least three symptoms indicating a risk of psychosis.
Symptoms indicating a risk of psychosis included:
Dr Miettunen said the findings were significant because they demonstrated a link with psychosis at a very early stage of cannabis use.
Parents and carers who are worried about a teenager's drug use can get help and advice from the website www.talktofrank.com or by calling the free helpline: 0800 776600