Married couples who smoke pot are less likely to behave violently toward each other, according to a new study.
Researchers surveyed hundreds of heterosexual couples over their first nine years of marriage, and when it came to considering marijuana use, the researchers found the lowest rates of domestic violence among pairs in which both husband and wife used marijuana more than once a week.
To be clear, the researchers are not suggesting that smoking pot is the key to a peaceful marriage, and the study, which appeared online this month in the journal Psychology of Addictive Behaviors, left many questions unanswered. [Trippy Tales: The History of 8 Hallucinogens]
"It is possible, for example, that — similar to a drinking partnership — couples who use marijuana together may share similar values and social circles, and it is this similarity that is responsible for reducing the likelihood of conflict," study researcher Kenneth Leonard, director of the University of Buffalo's Research Institute on Addictions, said in a statement.
For their survey, Leonard and colleagues recruited more than 600 couples as the pairs applied for marriage licenses in Buffalo, New York. The couples were also asked to complete five follow-up interviews, at their first, second, fourth, seventh and ninth wedding anniversaries.
Each time, the participants were asked how often they committed or were a victim of an incident of intimate partner violence (such as slapping, beating up and choking) during the previous year. They were also asked how often they used marijuana in the past year, with six options ranging from "not at all" to "more than once a week."
The researchers found that couples who used marijuana more frequently — including those who used the drug two to three times per month, once a week and more than once a week — reported less domestic violence perpetrated by husbands over the following year. Couples in which both spouses used marijuana at the highest rates reported the lowest rates of domestic violence.
The researchers found one exception to the general pattern, among wives who smoked pot more frequently and had committed acts of intimate partner violence before marriage. These women were more likely than wives who smoked pot less often to behave violently toward their spouses.
The study was limited in its ability to predict how marijuana affects daily behavior because the researchers did not examine whether smoking pot on a given day would reduce the likelihood of violence at that time, Leonard noted.
"Although this study supports the perspective that marijuana does not increase, and may decrease, aggressive conflict, we would like to see research replicating these findings, and research examining day-to-day marijuana and alcohol use and the likelihood to IPV (intimate partner violence) on the same day before drawing stronger conclusions," Leonard said in a statement.
The study was also restricted in its sample. It included only heterosexual couples who were entering their first marriage, and the researchers ultimately included in their dataset only the couples who stayed married. It is unclear whether these results would be replicated in same-sex couples, remarried couples, dating couples or couples married for longer than nine years, the authors wrote.
Although marijuana legalization has become increasingly popular among the American public, the drug's effects on public health are still debated. Pot does have some clear medical benefits — it can stimulate appetite in AIDS patients, and reduce nausea and pain in cancer patients undergoing chemotherapy. But previous studies have found that smoking pot during teen years is linked to brain abnormalities and lower IQ scores, according to a recent review of the adverse effects of marijuana published in the New England Journal of Medicine. The review also noted that smoking pot can have negative short-term effects like impaired coordination and an increased risk of car accidents.