“Because cannabis use is a potentially modifiable risk factor that has an adverse influence on the risk of relapse of psychosis and hospitalization in a given individual, with limited efficacy of existing interventions, these results underscore the importance of developing novel intervention strategies and demand urgent attention from clinicians and health care policy makers,” the authors wrote.
Whether the study conclusively demonstrates that it is cannabis use – and not genetic liability or reverse causation – that drives relapse of psychosis is still not clear. By the investigators’ own admission, the effect of discontinuing cannabis use on patient outcomes has not been tested, leaving the question of a definite causal relationship between continual cannabis use and relapse of psychosis still open for debate.
Ms. Schoeler and the other investigators – with the exception of Dr. Murray – reported no conflicts of interest. Dr. Murray reported that he has received honoraria from Janssen, Sunovion, Otsuka, and Lundbeck. The study was funded in large part by the U.K.’s National Institute for Health Research and by King’s College London.
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