This article is more than 5 years old. Information may no longer be current.

Persistent cannabis use linked to violence in mental health

Patients recently discharged from acute psychiatric care were more likely to exhibit violent behaviors if they reported continued cannabis use.

“While cannabis is a main substance of use in reports on arrests, violence, emergency room and therapeutic admissions as well as involuntary injuries, the existing literature on its association with violence is more limited, notably amid psychiatric patients with most studies provided from the general population,” Jules R. Dugré, PhD, of Universitaire en Santé Mentale de Montréal, and colleagues wrote. “Unlike studies of other drugs, the cannabis-violence relationship has provided controversial results.”

To determine if persistency of cannabis use predicts violence after acute psychiatric discharge, researchers analyzed data from the MacArthur Risk Assessment Study for 1,136 psychiatric patients recently discharged.

Analysis indicated a unidirectional association between cannabis use and violence.

The generalized estimating equations model indicated participants who continued to use cannabis across more than one time wave had increased risk for future violent behavior.

Participants who reported using cannabis at each follow-up were 2.44 times more likely to exhibit violent behaviors (OR = 2.44; 95% CI, 1.06-5.63).

“Our results are particularly relevant and may have clinical and violence risk management implications as we exposed that the persistency of cannabis use across different time waves was associated with an increased risk of violence in a large sample of patients recently discharged from acute psychiatric facilities,” the researchers wrote. “The results from this study show the necessity of further literature on the topic to specify the dose-response relationship with violence. This will have an important impact on preventive strategies to limit the risks of violence associated with cannabis that leads to many major social and health consequences.” – by Amanda Oldt

Disclosures: Dugré reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.