(HealthDay) -- About 10 percent of fibromyalgia patients use marijuana to relieve symptoms such as pain, fatigue and insomnia, a new study has found.
Fibromyalgia is a chronic condition that causes widespread pain, fatigue, headaches, sleep disturbances and other symptoms. It affects up to 3 percent of people and is more common among women.
Standard drug treatments for fibromyalgia-related pain provide only modest relief, and some patients self-medicate with marijuana and other traditional therapies, said Dr. Mary-Ann Fitzcharles, a professor of medicine at McGill University and consulting rheumatologist at the Montreal General Hospital of the McGill University Health Centre in Montreal.
She and her colleagues looked at the use of marijuana or prescription cannabinoids such as nabilone and dronabinol among 302 patients with fibromyalgia and 155 patients with another chronic pain condition.
About 13 percent of all 457 patients used cannabinoids, with 80 percent using marijuana. Smaller numbers used prescription cannabinoids, according to the study findings published online June 21 in the journal Arthritis Care & Research.
Of the patients who smoked marijuana, 72 percent reported using one gram or less per day, though a few smoked significantly more.
Patients who used marijuana were more likely to have unstable mental illness, to seek opioid painkiller drugs and to be unemployed, the investigators found.
"While self-medicating with cannabinoids may provide some pain relief to fibromyalgia patients, we caution against general use of illicit drugs until health and psychosocial issues risks are confirmed," Fitzcharles concluded in a journal news release.
"Physicians should be alert to potential negative mental health issues in fibromyalgia patients using illicit drugs for medical purposes. Some herbal cannabis users may be dishonestly using a fibromyalgia diagnosis to justify self-medicating with illegal drugs," she added.
Explore further: Fatigue not a factor in fibromyalgia pain, study says
More information: The American Academy of Family Physicians has more about fibromyalgia.