The Role of Cannabis in Opioid Addiction Treatment
Marijuana has the potential to assist in the treatment of many conditions. There is ongoing research and debate about whether cannabis helps with opioid addiction. Could it play a helpful role in reducing harms from the opioid crisis — for example, by reducing pain, substituting for opioids, easing withdrawal, or lowering overdose risk? To date, the evidence is mixed, and this approach is associated with significant risks, limitations, and uncertainties. Below is a breakdown of what we do know, what is speculative, and what would need to be true for cannabis to be part of the addiction solution — plus what policy/practice implications, caveats, etc., would apply.
What the evidence says so far
Here are findings from recent studies and reviews, including strengths and limitations.
Potential Benefits / Positive Findings
Substitution for pain meds/opioids
- In states with medical cannabis laws, surveys show many people with chronic pain report using cannabis instead of or in addition to prescription opioids, reducing their opioid dose. (JAMA Network)
- One study of Medicare Part D showed that when states enacted medical cannabis laws (especially when dispensaries are operational), opioid prescribing dropped significantly. (The Independent)
Analgesic synergy / opioid-sparing potential
- Some preclinical and small clinical data suggest that cannabinoids + opioids can have synergistic pain relief, meaning you might need lower opioid doses for equivalent pain control. Lower doses may mean lower risk of dependence or overdose. (Liebert Publications)
Harm reduction/withdrawal relief
- Some qualitative/observational studies report that people use cannabis to manage opioid withdrawal symptoms, cravings, and anxiety. For some, this helps reduce the use of more dangerous opioids that could lead to addiction. (The Guardian)
Policy / population-level associations
- "Cannabis legalization / medical cannabis laws" have been associated in some studies with modest reductions in opioid prescribing. (PubMed)
- But whether legalization lowers opioid overdose deaths is much more mixed / less clear. Some studies find no effect; others show small/modest reductions. (Stanford Medicine)
Limitations / Negative / Mixed Findings for the Role of Cannabis in Opioid Addiction Treatment
Lack of strong causal evidence
- Many studies use surveys and observational methods to collect data about cannabis and opioid use. These types of studies make it hard to know for sure if cannabis actually helps with opioid addiction or appears to be linked to lower opioid use. Rather than a direct cause-and-effect relationship, people who are open to trying non-opioid pain relief options may also be more likely to try cannabis for pain management. Because of this, researchers are still working to understand precisely how medical cannabis may support people in reducing or managing opioid dependence and addiction. (Wiley Online Library)
Mixed results on overdose mortality
- Some research that initially found medical cannabis laws correlated with lower opioid overdose deaths has not held up when researchers extend the study durations. In some cases, the effect reversed. (Stanford Medicine)
- Even when prescriptions go down, illicit opioid use (like fentanyl) is a major driver of overdose risk, and reductions in prescriptions may not map directly to fewer overdoses. (Wiley Online Library)
Risk of dual use / increased harm
- Some studies find that cannabis use does not reduce non-medical opioid use, and may even increase it in specific populations. E.g., one study found that among people who use non-medical opioids, using cannabis on a given day was associated with greater odds of non-medical opioid use that same day. (Mailman School of Public Health)
- People with opioid addiction are more likely to have chronic pain, co-occurring mental health issues, etc., and cannabis is not risk-free — there are risks of mental health effects, cannabis use disorder, etc. Furthermore, cannabis is not a proven treatment for opioid use disorder in the way traditional drug-assisted therapies are. (Wiley Online Library)
Heterogeneity
- Effects vary by how cannabis is accessed (medical vs recreational, dispensary vs informal), what kind of products people use (THC vs CBD; route of administration; dosing), and by individual differences (pain type, predisposition to substance use, etc.).
- Additionally, there is variation across states/countries, depending on policies, regulations, and the availability of evidence-based treatments, among other factors. What works in one setting may not work in another.
What we need to be true to show that cannabis helps with opioid addiction
If cannabis is to play a meaningful role in opioid addiction, the studies must meet several conditions:
Better evidence
- Randomized controlled trials that test whether cannabis (or specific cannabinoids) can reduce opioid use, reduce cravings, and/or reduce overdose risk, ideally in well-defined populations (e.g., people with chronic pain taking prescription opioids; people with opioid use disorder).
- Longitudinal data with enough follow-up to assess risks (e.g., whether cannabis use leads to dependence, or increases risks in certain people).
Safe product standards
- Reliable dosing, quality control (purity, absence of contaminants, known THC/CBD ratios).
- Products that minimize harm (e.g., less addictive components; routes of administration that reduce respiratory or other harms).
Integration into medical care
- Clinicians need guidance on when cannabis may be appropriate as an adjunct or substitute for opioids (for which patients, what kinds of pain or opioid use, what dosage, and what monitoring).
- Ideally, regulatory frameworks that allow for medical cannabis use where evidence supports it, under medical supervision.
Complementary harm reduction/treatment infrastructure
- Cannabis alone is unlikely to resolve the opioid crisis. Other proven interventions are essential: medication-assisted treatment (e.g., methadone, buprenorphine), naloxone distribution, overdose prevention, safe supply, access to mental health care, etc.
Policy design that mitigates risks
- Ensuring access doesn't lead to increased misuse or unintended harms (e.g., driving impairment, mental health issues).
- Monitoring and surveillance systems to detect both benefits and harms.
Bottom line: The Role(s) of cannabis in opioid addiction treatment, and what is uncertain
So summarizing:
- Cannabis is a potential tool to reduce harm in some contexts: e.g., for chronic pain patients lowering opioid dosages, or for people with opioid dependence to ease withdrawal or cravings. That might lower risks of overdose or other harms.
- Legalization or medical cannabis laws may help reduce prescription opioid use in some populations. But whether this consistently translates into fewer overdose deaths is far less specific.
- Cannabis is not a proven treatment for opioid use disorder in the way that FDA‑approved medications (like methadone, buprenorphine) are.
- There are risks: using cannabis to help with opioid addiction has its own side effects; in some people, it might worsen outcomes; dual substance use may complicate matters.