Marijuana has been proven to be effective in reducing the nausea induced by cancer chemotherapy, stimulating appetite in AIDS patients, and reducing intraocular pressure in people with glaucoma.

None of the medical tests currently used to detect brain damge in humans have found harm from marijuana, even from long term high-dose use. The claim that marijuana kills brain cells is based on a speculative report dating back a quarter of a century that has never been supported by any scientific study.