Lester Grinspoon, MD, Professor of Psychiatry at the Harvard Medical School, stated in an Apr. 1998 Journal of Psychoactive Drugs article:

“Thirty percent to 40% of patients with bipolar disorder are not consistently helped by or cannot tolerate standard medications. In the course of the authors’ studies of the medical uses of cannabis (Grinspoon & Bakalar 1997), a number of sufferers were discovered who believed marihuana to be more effective than conventional anti-manic drugs, or who used it to relieve the side effects of lithium.”

Apr. 1998