Background

The use of marijuana for medical purposes is increasing in parallel with expanding legalization and decreased public perception of harm. Despite this increase in use, it is unclear which medical conditions patients are attempting to treat with marijuana and whether they are communicating with medical providers about their use.

Objective

To understand the medical reasons for marijuana use, forms of marijuana used for medical purposes, and disclosure of use to physicians.

Design

National, probability-based online survey.

Setting

The USA, 2017.

Participants

16,280 US adults.

Main measure

Proportion of US adults who agreed with a statement.

Key results

A total of 9003 participants completed the survey (55% response rate). Five hundred ninety-one (7% of US adults) reported using marijuana for medical purposes. The most common medical reasons for marijuana use were anxiety (49%), insomnia (47%), chronic pain (42%), and depression (39%). The most common forms of use for all medical conditions were smoking and edibles, followed by vaping, concentrate, and topical. We found women were more likely to use marijuana for posttraumatic stress disorder, sleep, anxiety, and migraines. We did not find substantial variation in medical reasons for marijuana use by race. Among those using marijuana for medical purposes, 21% did not have a doctor. Among those with doctors, 33% did not inform them, 28% reported their doctor was neutral on their use, 32% reported their doctor was supportive, and 8% reported their doctor was not supportive. Those who lived in states where medical marijuana was illegal were less likely to disclose use to their doctor.

Limitation

The online format of the survey may have caused selection bias. Wording of the questions may have affected interpretation. Doctors were not queried directly, rather participants were asked about their perception of doctor attitudes.

Conclusion

Americans are using marijuana to treat medical conditions despite lack of evidence of efficacy.