Self-reported marijuana effects and characteristics of 100 San Francisco medical marijuana club members.

In order to assess the relationships between medical marijuana users' reasons for use, side effects, and drug use patterns, 100 participants were recruited from the San Francisco Cannabis Cultivator's Club. Users, averaging 14 years pre-illness use, perceived marijuana to be more effective than other treatments and to have less severe side effects. Urine drug assays showed recent use of other drugs, particularly stimulants. History of substance abuse or dependence and other psychiatric disorders was common. Those with greater past dependence on other drugs thought marijuana to be more effective but also reported worse side effects and quality of life. Quality of life was associated more with marijuana side effects rating than effectiveness. Patients reported potentially serious marijuana side effects on some questionnaires but not others. Inconsistencies in reporting made interpretation of results difficult. Physician supervision of medical marijuana use would allow more effective monitoring of therapeutic and unwanted effects, some unrecognized by patients.