Cannabis Expectancies Predict Use Patterns in Chronic Pain Patients More Than Pain Severity Does | Research

The takeaway

A survey of 258 chronic pain patients found that positive expectations about cannabis effects — not pain severity — were the strongest predictor of cannabis use frequency and problematic use.

Pain clinicians, cannabis prescribers, and patients using cannabis for chronic pain management.

What the researchers found

Positive cannabis expectancies (believing cannabis will help with pain, sleep, mood) were significantly associated with higher use frequency and cannabis use disorder symptoms, even after controlling for pain severity, anxiety, and depression. Pain severity itself was not a significant predictor of use patterns.

Why it matters

Clinicians often assume chronic pain patients use cannabis because of pain severity. This study suggests beliefs about cannabis matter more, which has implications for patient education and screening.

The numbers in context

258 chronic pain patients surveyed. Positive expectancies predicted use frequency (p<0.01) and CUD symptoms (p<0.001). Pain severity was not a significant predictor.

How the study worked

Cross-sectional survey of 258 adults with chronic pain who used cannabis. Validated measures for cannabis expectancies, pain severity, mental health, and cannabis use disorder.

What this study cannot tell us

Cross-sectional design cannot determine causation. Self-selected sample of cannabis users. Expectancies and use measured simultaneously. No longitudinal follow-up.

How to read the evidence

Well-powered cross-sectional study with validated measures, but cannot establish causal direction between expectancies and use.

When this study was published

2025 study examining psychological drivers of cannabis use in chronic pain.

The bigger picture

Understanding why people use cannabis is as important as understanding whether it works. If expectancies drive use more than symptoms, targeted education about realistic outcomes could help patients make more informed decisions.

Questions still open

Could correcting unrealistic cannabis expectancies reduce problematic use in pain patients?
Do expectancies change after prolonged cannabis use for pain?

Common questions

Why do chronic pain patients use cannabis?

This study found beliefs about cannabis benefits mattered more than actual pain severity in predicting use patterns, suggesting psychological expectations drive use more than symptom relief needs.

Can expecting cannabis to help lead to overuse?

Yes — higher positive expectancies were associated with both more frequent use and more symptoms of cannabis use disorder in this chronic pain sample.

Read the original research

Cannabis expectancies and associations with cannabis use and health functioning among adults with chronic pain.

Addictive behaviors, 160, 108166

View on PubMed ↗Publisher’s paper ↗

Citation

Tomlinson, Devin C; Coughlin, Lara N; Bohnert, Kipling M; Ilgen, Mark A. (2025). Cannabis expectancies and associations with cannabis use and health functioning among adults with chronic pain.. Addictive behaviors, 160, 108166. https://doi.org/10.1016/j.addbeh.2024.108166