Professor Sir Robin Murray, from King's Institute of Psychiatry, Psychology and Neuroscience, examines the evidence of links between cannabis use and psychosis.

The best-established risk factors for psychosis are obstetric events, childhood adversity, migration, being brought up in a city, adverse life events and cannabis use. Some are proxies for an unknown causal factor (e.g. urbanicity), while preventing others (e.g. childhood adversity) is beyond our powers. Cannabis use is the environmental component cause for which the evidence is strongest, and recent reports indicate that more than 20% of cases of psychosis in London could be prevented if no-one smoked high potency cannabis. Is it not time to initiate public education about the risks of the heavy use of cannabis, especially of high potency varieties?

This seminar is free and open to all.