Robin Murray

In other words, it's a highly nuanced and complex relationship with plenty of other factors at play.

As a clinician, I've seen how heavy cannabis users can be a factor in violence, said co-author and King's College London professor Martin DeFordy in a statement.

We've been cautious for a long time about how far we would go to describe this link, but the review of this size lets us speak with more confidence about the risks while being careful not to stigmatize people who use cannabis more broadly.

As cannabis becomes more commercialized and legalized around the world, the conversation about its risks is focused mostly on the person using it, added co-author and King's College London professor of psychiatric research Sir Robin Murray.

This review shows that violence, both committing it and experiencing it, needs to be part of that conversation too.

For their paper, the researchers examined 63 cannabis-related studies involving over 265,000 subjects.

This association was stronger among women than am- among men.

Professor Sir Robin Murray, senior author of the study from the Institute of Psychiatry, Psychology and Neuroscience at King's College London said In the general population, people who used cannabis were around twice as likely to have committed a violent act as those who didn't.

For those in psychiatric care, cannabis users were around two and a half times as likely to be violent as other psychiatric patients who didn't use cannabis.

The link held in studies that followed people over time, though it was smaller than in studies that looked at a single point in time.