Marijuana’s Cooling Effect on Partner Violence

Intimate partner violence (IPV) affects millions of Americans every year. Ranging from acts of violence, sexual violence, stalking, and psychological aggression, IPV affects individuals of all sexual orientations and gender identities. IPV is most commonly perpetrated against women, with highest prevalence among bisexual women who suffer more from substance use, social hyper-sexualization, and phobia-based harassment than straight or lesbian women. Substance use and intimate partner violence are interrelated, as heavy alcohol and drug use are known risk factors for increasing violence in relationships. However, not all drugs increase the risk for IPV. New research is uncovering that marijuana may reduce the risk of violence between intimate partners.

Since 2012, legislation legalizing the recreational use of marijuana has passed in nine states and Washington DC. Although marijuana remains a Schedule 1 drug according to the Drug Enforcement Agency and illegal on the federal level, the Department of Justice does not give priority to prosecuting medical marijuana users. As marijuana becomes more available, there is increasing media attention on the negative potential of cannabis when used recreationally. Yet the news about marijuana’s unexpected effects is not all bad. Philip H. Smith and his research team from SUNY Buffalo conducted a longitudinal study to measure the association between marijuana use and IPV among heterosexual couples during the first nine years of marriage.

Over six hundred couples were surveyed using in-home questionnaires in the first wave of data collection and five waves of follow-up. The researchers set out to understand how marijuana use predicts IPV perpetration in relationships, and studied whether there is a difference when used by only a single individual or both partners.

IPV perpetration was lowest when both husband and wife reported “frequent smoking” (around once a week).

Husbands more frequently reported marijuana use; wives reported higher rates of IPV. Overall, increased marijuana use was found to be significantly associated with less frequent IPV perpetration. For a subset of participants, marijuana use was found to increase IPV perpetration among wives who used marijuana and reported IPV prior to marriage. Otherwise, as couples’ consumption of marijuana increased, reported instances of intimate partner violence decreased. IPV perpetration was lowest when both husband and wife reported “frequent smoking” (around once a week).

Relatedly, a longitudinal study conducted by Dr. Emily Rothman at Boston University found that, unlike alcohol, marijuana did not increase the risk for dating violence among surveyed participants.  Most studies of the marijuana-violence nexus have been cross-sectional, which has limited their findings, and produced mixed results. Smith’s study, and Rothman’s, give us a longitudinal picture of the association between IPV and marijuana use, and suggest that marijuana may reduce the risk of violence between intimate partners.

Feature image MagMos/iStock