Scientific interest in medicinal marijuana is blooming. It has been kindled, in part, by the recent discovery of a molecular signaling system in the brain and other parts of the body activated by cannabinoids, naturally occurring compounds that are chemical cousins to THC (tetrahydrocannabinol), the active ingredient in marijuana, according to Abrams. Research suggests this system affects movement and emotional excitability, appetite and the growth of cancerous tumors -- and may be as potent as morphine in reducing pain. These findings may explain why smoking marijuana has a calming effect, combats nausea or gives users the munchies.
An AIDS doctor since the epidemic began, [Donald I. Abrams] knew many of his patients smoked pot to curb nausea and stimulate their appetites, which is why he wanted to study its medicinal potential. In 1998, after a lengthy battle to get funding from the National Institute on Drug Abuse, Abrams conducted the first test of pot on people with HIV. That study showed marijuana helped patients gain weight without weakening their immune system.