Using Marijuana Is Tied To Lower Consumption Of Alcohol, Opioids And Other Drugs, New Study Reveals

A new study on the impact of marijuana consumption on people’s use of other drugs suggests that for many, cannabis may act as a less-dangerous substitute, allowing people to reduce their intake of substances such as alcohol, methamphetamine and opioids like morphine.

The survey, of 23,500 people in New Zealand, asked participants about whether their use of cannabis had any influence on their consumption of other substances. For the most part, it found that marijuana use was associated with reduced frequency and quantity of use of other certain substances.

“Significant proportions reported cannabis use led to ‘less’ alcohol (60%), synthetic cannabinoid (60%), morphine (44%) and methamphetamine (40%) use,” the new report says. “Those who reported using ‘less’ had lower frequency and amount used of other drugs.”

That said, results varied by substance as well as demographics. Nearly 70 percent of people said cannabis had “no impact” on LSD, MDMA or cocaine use, for example. One-third of cannabis and tobacco co-users reported using less tobacco, while an even smaller minority of respondents—1 in 5—reported that using marijuana actually led to more tobacco use.

Substituting cannabis for other drugs also appears more popular among young adults, aged 21 to 35, who were more likely than other groups to report that cannabis lowered their consumption of alcohol and methamphetamine. Students and people living in cities, meanwhile, were less likely to say that marijuana reduced their use of other drugs.

Impact of cannabis use on the use of eight other drug types. Wilkins et al. / Harm Reduction Journal

Use of marijuana by adolescents (16 to 20 years old), meanwhile, had mixed results, with that cohort being “both more likely to report cannabis use resulting in ‘more’ and ‘less’ other substance use compared to having ‘no impact,” the study found. Younger adults (21 to 25 years old), by contrast, “were more likely to say cannabis use resulted in lower use of alcohol, methamphetamine, and MDMA.”

“Significant proportions of people who use cannabis in our survey reported that using cannabis led to lower levels of alcohol and methamphetamine use.”

The results contribute to what’s still a mixed picture in terms of whether—and to what extent—people are using marijuana as a substitute for other drugs, authors noted. For example, they note, a study of U.S. college students “found that following cannabis legalisation there was a reduction in binge drinking alcohol among students aged 21 or older but not among younger students,” while at the same time “other studies of U.S. college students have found no impact on other drug use.”

Similarly conflicting outcomes have been seen in jurisdictions that have legalized marijuana, the study points out. For instance, it says, “monthly purchases of alcohol (specifically wine) declined in Colorado and Washington state after the legalization of recreational cannabis, while purchases of spirits increased in Washington state but decreased in Oregon after cannabis legalization.”

Another study “found Canada-wide monthly beer sales dropped after cannabis legalization, but there was no change in spirits sales,” the report adds. “In contrast, other studies of U.S. legalisation states found cannabis legalization resulted in no change in alcohol purchase and use.”

Venturing to explain the association, authors note that when it comes to drinking, “the substitution of legal cannabis for alcohol may reflect the similar neurological effects of each substance, similar social acceptability among young people, and comparable price,” adding that some studies of college students “have found some were motivated to use cannabis as a mean[s] to reduce their alcohol consumption and related negative outcomes.”

As for age-related differences, the four-person research team, from Massey University College of Health in Auckland, described a complicated picture involving both culture and physiology:

“Our mixed findings may reflect different life stages and developmental trajectories. The youth age cohort (16–20 years) is a time of transition from adolescence to young adulthood and is associated with risk-taking and novelty seeking and has been identified as a period of high risk of developing substance co-use. The next older cohort (21–35 years) has greater neurological development and often accumulated real world experience of alcohol and other drug use, including related negative consequences of poly drug use, and hence may be more likely to consider harm reduction behaviour, such as favouring substances with fewer side effects and less harmful consequences.”

They also pointed to another recent literature review suggesting that cannabis-and-alcohol interactions may be age dependent, “suggesting that older age may moderate the level of substitution and complementarity behaviour.”

“Our findings have a number of implications for harm reduction,” the new paper says. “Firstly, greater access to cannabis could provide opportunities for older young adults (20 years old+) to reduce excessive alcohol consumption within an age group with high prevalence of risky drinking. Cannabis may provide a lower risk option than heavy alcohol use among young adults who are in a particularly hedonistic phase of their lives.”

“Secondly,” authors said, “greater access to cannabis could play a part in reducing methamphetamine use for some individuals, either as a means to reduce the frequency of methamphetamine consumption, or as an adjunct to support treatment for methamphetamine related issues. Several harm reduction studies have indicated the potential of medicinal cannabis to support reduction in the use of other drugs with have higher risk of side-effects, including stimulants and prescription opioid analgesics.”

Harm reduction programs hoping to take advantage of the findings, the study says, “could include peer and community run programs offering free or low-cost cannabis to disadvantaged people experiencing substance use issues.”

Among New Zealand’s indigenous Māori population, respondents were more likely to report that marijuana use reduced intake of alcohol, tobacco, methamphetamine and LSD.

“It is important to note that while young adults, males and Māori in our study were all more likely to report cannabis leading to ‘less’ alcohol use, all these groups have higher baseline rates of hazardous drinking in New Zealand,” the report says.

Regarding efforts in the country to prioritize Māori applicants for retail cannabis business licenses, it adds, “It could be argued, based on our results, that these provisions would not only provide Māori with the opportunity to enter the legal cannabis industry, but also provide enhanced access to legal cannabis to lower drinking and other drug use.”

General awareness of the substitution effect is growing among not only researchers but also market observers. A report from Bloomberg Intelligence earlier this year said the expansion of the marijuana legalization movement will continue to pose a “significant threat” to the alcohol industry as more people use cannabis as a substitute for alcohol

That report estimated that the combined influence of cannabis access and shifts in consumer demand for certain alcoholic product types accounts for a 16 percent share valuation discount offered by the beverage company Constellation Brands, which owns major brands including Corona, Modelo, Pacifico and Casa Nobel Tequila.

Another study out of Canada, where marijuana is federally legal, found that legalization was “associated with a decline in beer sales,” suggesting a substitution effect.

The analyses comport with other recent survey data that more broadly looked at American views on marijuana versus alcohol. For example, a Gallup survey found that respondents view cannabis as less harmful than alcohol, tobacco and nicotine vapes—and more adults now smoke cannabis than smoke cigarettes.

A separate survey released by the American Psychiatric Association (APA) and Morning Consult last June also found that Americans consider marijuana to be significantly less dangerous than cigarettes, alcohol and opioids—and they say cannabis is less addictive than each of those substances, as well as technology.

Additionally, a poll released in July found that more Americans smoke marijuana on a daily basis than drink alcohol every day—and that alcohol drinkers are more likely to say they would benefit from limiting their use than cannabis consumers are.

Similarly, a separate study published in May in the journal Addiction that similarly found that there are more U.S. adults who use marijuana daily than who drink alcohol every day.

Outside of alcohol, a recent study also found that marijuana has a “great deal of potential” to treat opioid use disorder.

“Upon a review of the literature, it is reasonable to conclude that cannabis has some efficacy in the setting of opiate maintenance, as well as other therapeutic uses,” that paper said. In light of public concerns over opioid overdoses and the possibility of marijuana being rescheduled, it added, “there is a distinct possibility that cannabis use in harm reduction models will increase.”

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