Psychiatric patients who smoke cannabis are more than twice as likely to turn to violence as those who do not take the drug, a study has shown.
Scientists in Canada claim that they have found the first strong evidence for a “uni-directional” relationship that suggests that sustained cannabis use could lead people with severe mental illnesses to commit assaults and other violent crimes.
For decades the links between marijuana, psychosis and violence have proven difficult for researchers to disentangle definitively.
While several studies have shown that cannabis users, particularly those with underlying mental disorders, are more likely to behave aggressively towards others, it is not yet clear whether the drug is to blame.
A team led by Jules Dugre, a psychologist at the University of…