Marijuana might not be an optimal parenting hack for everyone, despite some claims to the contrary.

Parents who have used marijuana in the past year are more likely than non-users on average to discipline their kids through corporal punishment (like a slap or spank), physical abuse (like a hit on the head or a kick) and also nonviolent tactics (like loss of privileges or time-outs), according to a new study examining 2009 data on the impact of substance use on parenting.

“We tend to have this view that marijuana use has this calming, [relaxing] effect on people,” lead study author Bridget Freisthler, a professor at the Ohio State University, told MarketWatch. “People who use marijuana, that’s not how they discipline,” she added. “It’s not that they have a laissez-faire attitude about discipline. They’re using all types of discipline.”

“ As doctors continue to recommend marijuana for medical conditions, Bridget Freisthler, a lead author on the study, stressed the importance of considering the combined effects of multiple substances. ”

Those who used marijuana and drank alcohol over the past year, Freisthler said, “had some of the biggest risks for physical abuse.” More than 92% of parents who had used marijuana in the past year also reported using alcohol over the past 12 months, the authors noted. That may be contributing to the higher instances of physical abuse, they added.

However, the average annual frequency of physical abuse was 0.5 times greater for those reporting past-year use of both marijuana and alcohol than it was among those who only drank — “further highlighting the particular importance of polysubstance use for physically abusive behaviors,” they wrote.

Freisthler stressed the importance of considering the combined effects of multiple substances as doctors continue to recommend marijuana to treat medical conditions. Primary-care physicians screening their patients for alcohol use may also want to screen specifically for marijuana use instead of asking about other drug use in general, she added, to determine whether the person is in a high-risk category and “might need additional support around parenting.”

The study, supported by the National Institute on Alcohol Abuse and Alcoholism, was published in the Journal of Social Work Practice in the Addictions.

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Freisthler and her co-author, University of Kansas assistant professor Nancy Jo Kepple, analyzed 2009 data from a land-line telephone survey of more than 3,000 parents in 50 California cities. Respondents were English- or Spanish-speaking adults who were parents or guardians to a child aged 12 or under residing with them at least half of the time.

Despite the surprising finding about parents who use marijuana, Freisthler stressed that the study only captured their behavior at one point in time, making it hard to draw any broad conclusions. “We don’t know when they’re using it and when these parenting behaviors co-occur,” she said.

And while the study didn’t examine the reasons behind these discipline styles, Freisthler speculated that the paranoia some people experience when consuming marijuana could play a role with a certain group of users. Some parents could also be reacting with frustration to their kids’ disruptive behavior when they’re trying to relax with the drug, she suggested.

“ Some parents have extolled ‘the distinct highs of parenting while stoned’ and claimed that ‘cannabis has strengthened the bond I have with my daughter,’ saying they have a greater capacity to be present. ”

“There’s certainly a subset of the population that does think it does make them better parents,” Freisthler said. “The message [here] is that it doesn’t, necessarily.”

Indeed, some parents have extolled “the distinct highs of parenting while stoned” and claimed that “cannabis has strengthened the bond I have with my daughter,” citing reasons including a greater capacity to be present, the opportunity for candor around drug use, and the side effect of decreased alcohol consumption.

Cannabis use among cigarette-smoking parents with kids living at home rose from 11% to 17% between 2002 and 2015, according to a 2018 study in the journal Pediatrics, and from 2% to 4% among those who didn’t smoke cigarettes.

And some research suggests that marijuana isn’t always the mellowing agent it’s cracked up to be: One 2015 study of young adults in the journal Drug and Alcohol Dependence found that “any marijuana use, independent of alcohol consumption, was associated with same day increases in impulsivity, one’s own hostile behaviors, and perceptions of hostility in others.” A separate 2017 study in the same journal found that while low doses of THC helped reduce stress, higher doses increased “negative mood.”

Meanwhile, the District of Columbia and 11 states — most recently Illinois — have legalized marijuana for recreational use. Medical marijuana is legal in 33 states and D.C.

“I think there’s enough concern that we should be paying attention to it more,” Freisthler said. “[But] I don’t know that there’s enough concern to raise the alarm and say, ‘All these people are bad parents.’”

As for parents who use marijuana, Freisthler suggested having safeguards in place to ensure the kids are OK.

One of her colleagues offered an idea, she said, in the same vein as a designated driver for drinkers: “If you’re going to be using marijuana and alcohol, should there be a designated parent so you’re not the parent taking care of discipline during those times of use?”