Marijuana Use May Stymy Drug and Alcohol Abstinence, New Study Finds
Patients who use marijuana have lower odds of achieving abstinence from other drugs and heavy alcohol use, indicating that marijuana use merits attention from addiction-treatment clinicians, a new study by researchers from the BU schools of public health and medicine has found.
The study, published online in the journal Drug and Alcohol Dependence, examined the association between marijuana use and abstinence from opioid or stimulant drugs or alcohol.
The authors noted that marijuana theoretically could have a helpful or harmful influence on achieving sobriety: Substituting a less harmful drug might help to achieve abstinence from other drugs, while on the other hand, continued use of an addictive drug such as marijuana could interfere with efforts to quit other drugs, or have no impact at all. Prior studies have lent some support for each of those possibilities.
The new study — which recruited more than 500 participants with opioid, cocaine and alcohol use disorders, primarily from an inpatient detoxification unit – found that marijuana use was associated with a 27 percent reduction in the odds of abstinence from drug and heavy alcohol use.
“While the findings may not mean addressing marijuana use during addiction treatment will improve treatment outcomes, they do suggest that possibility,” said the research team, led by Dr. Richard Saitz, chair of community health sciences at BUSPH and professor of medicine at the BU School of Medicine. “It seems reasonable to address marijuana use in substance-dependent people and in their treatment.”
One recent study found that pre-treatment marijuana use favorably influenced abstinence rates in cocaine users, compared to no pre-treatment marijuana use. But other studies have shown that marijuana use is associated with worse treatment outcomes in patients undergoing opioid agonist treatment. And still other research has found alcohol and marijuana use to be independent of one another.
The authors said they hoped their findings might help to clarify the conflicting evidence.
“Our study followed participants over a year and included laboratory testing for drugs and alcohol, and analyses adjusted for addiction severity — making it likely that the association between marijuana use and other drug and heavy alcohol use is real,” said Saitz.
“The findings might be useful for prognosis—so patients and clinicians alike can be aware that marijuana use in this circumstance increases the risk of subsequent other drug use. They are also useful because of implications for treatment or self-change. They imply that continued use of marijuana is not harmless,” added Saitz.
Saitz said that use of marijuana might increase the risk for other drug use because, like nicotine, it “stimulates the same reward pathways” in the brain.
“Continuing to stimulate those pathways with any drug could be related to using other drugs, some of which are more potent and harmful, as has been found for cigarette smoking,” he said.
The study was funded by grants from the National Institutes of Health to Boston Medical Center.
Authors include: Mohammadali Mojarrad, a student at the BU School of Medicine; Dr. Jeffrey H Samet, professor of Medicine, BU School of Medicine and chief of general internal medicine at Boston Medical Center; Debbie M. Cheng, professor of biostatistics at BUSPH; and Michael R. Winter, associate director of the BUSPH Data Coordinating Center.