Cannabis Use Disorder: The Addiction Nobody's Treating — and GLP-1s Might

A Growing Problem With No Medication

Cannabis legalization across the United States has been accompanied by a rise in cannabis use disorder — a clinical diagnosis characterized by continued use despite significant impairment or distress, tolerance, withdrawal symptoms, and inability to cut down despite wanting to. An estimated 16 million Americans meet the criteria for CUD, and among certain demographics, cannabis use disorder prevalence now exceeds that of tobacco use disorder.

Unlike alcohol, opioids, and nicotine — each of which has at least one FDA-approved medication — cannabis use disorder has none. The only evidence-based treatments are psychosocial interventions like cognitive behavioral therapy and motivational enhancement therapy. While these can help, their long-term efficacy is limited, and many people with CUD never seek treatment in the first place.

This pharmacological void is what makes the semaglutide findings particularly significant.

The Molecular Psychiatry Study

Researchers at Case Western Reserve University, led by Dr. Rong Xu in collaboration with NIH's Dr. Nora Volkow, published a retrospective cohort study in Molecular Psychiatry examining semaglutide's association with cannabis use disorder in real-world populations.

The study examined two patient populations: those with type 2 diabetes (using data from December 2017 through May 2021) and those with obesity (using data from June 2021, when semaglutide was approved for weight management, through December 2022). In both populations, semaglutide users were compared to matched groups taking other medications for the same condition.

The key finding: in the obesity cohort, semaglutide was associated with a 44% reduction in the incidence of cannabis use disorder. The drug was associated with reduced risk of both new CUD diagnoses and recurrence of CUD in people who had been previously diagnosed — suggesting effects on both prevention and relapse prevention.

Why Cannabis Is Different

Cannabis addiction operates through the endocannabinoid system, which interacts with but is distinct from the dopamine reward pathways targeted by GLP-1 agonists. THC, the primary psychoactive component of cannabis, binds to CB1 receptors in the brain, triggering downstream dopamine release in the nucleus accumbens.

The fact that GLP-1 agonists appear to reduce CUD risk despite cannabis working through a different receptor system supports the theory that these drugs target something more fundamental than any one substance's mechanism — they modulate the shared reward processing infrastructure that makes any substance feel compelling.

The researchers noted that since semaglutide reduced not just relapse but also the incidence of new CUD, it may be affecting the transition from casual cannabis use to disordered use — potentially by reducing the escalation of reward-seeking behavior before it becomes compulsive.

Confirmation From the WashU BMJ Study

The March 2026 WashU BMJ study provided independent confirmation, finding a 14% reduced risk of developing new cannabis use disorder among GLP-1 users in the 606,434-veteran cohort. While this is the most modest reduction among the five substance categories studied (opioids showed 25%, cocaine and nicotine showed 20%, alcohol showed 18%), it's nonetheless a consistent signal across a very large population.

What's Missing

No randomized controlled trial has tested GLP-1 medications specifically for cannabis use disorder. The current evidence is entirely observational. The researchers at Case Western Reserve explicitly called for both preclinical studies of semaglutide on THC (the active component) and randomized clinical trials evaluating therapeutic benefits in CUD patients — including patients who don't have obesity or diabetes as comorbid conditions.

The mechanism underlying the decreased CUD risk remains unclear. It could involve direct modulation of reward circuits, indirect effects through weight loss and metabolic improvement, changes in mood or anxiety that reduce self-medication with cannabis, or some combination of these factors.