A study analyzing self-reports from patients with fibromyalgia who were referred to a ter­tiary care pain center indicate that 13% used cannabi­noids to manage their pain. Among these patients, 80% used marijuana, 24% used prescription cannabi­noids, and 3% used both. Users tended to be unem­ployed and receiving disability payments. Marijuana use was associated with:

Unstable mental illness (36%).
Male gender (26%).
Opioid drug-seeking behavior (17%).

Abstract: Arthritis Care & Research, June 21, 2012 (online).