Can medical cannabis help chronic pain patients taper off opioids?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Men and women aged 18-75, inclusive. 2. Endorsing \> 6 months of chronic, non-cancer pain. 3. On stable prescription opioid doses of 25 MME or greater for \>90 days, verified by the Prescription Monitoring Program. 4. Either no prior use or current light cannabis use (weekly or less in the past 12 months). 5. Plans to use medical cannabis for pain to control pain and/or reduce opioid dose. 6. Competent and willing to provide written informed consent in English. 7. Potential participants of childbearing potential must not be pregnant at enrollment. They will be asked to self-report pregnancy status and the start date of their most recent menstrual period and agree to use effective contraception: abstinence; hormonal contraception; intra-uterine device, sterilization; or double barrier contraception, during the study. Exclusion Criteria: 1. Current cannabis use (including inhaled or ingested CBD products) of greater than weekly on average in the past 12 months, assessed via self-report (no more than 10 times in the past 90 days). 2. Current cannabis use disorder; current moderate to severe substance use disorder for any substance by structured interview, EXCEPT nicotine and opioids (OUD). 3. Current uncontrolled major medical illness, such as cancer, symptomatic hypothyroidism/hyperthyroidism or severe respiratory compromise. 4. Use of non-prescribed opioids, by self-report. 5. Dose change or initiation of medications with significant analgesic effects (e.g., tricyclic antidepressants, SSRIs, gabapentin, NSAIDs) in the past 4 weeks. 6. Concomitant medications will be discussed at each study visit, and any medications that may interact with cannabinoids (e.g., warfarin) will be discussed with a study clinician prior to enrollment or continued participation. 7. Actively suicidal and/or suicide attempt or psychiatric hospitalization in past year, or current suicidal ideation with specific plan or intent. 8. History of intellectual disability (e.g., Down's syndrome) or other severe developmental disorder or IQ \< 70. 9. Current diagnosis of delirium, dementia, amnestic, or other cognitive disorder; current diagnosis of bipolar II disorder; lifetime diagnosis of bipolar I disorder, schizophrenia spectrum, or other psychotic disorder. 10. Surgery within the past month or planned during the next 6 months. 11. Pregnant or trying to get pregnant or breastfeeding. 12. In the opinion of the investigator or study physicians, not able to complete study procedures or safely participate in this study.