The Physical and Psychological Effects of Marijuana Marijuana has been used as a drug since the beginning of time, yet there are still many mysteries about its health effects on humans. Marijuana, or cannabis sativa, is a preparation of the crushed flowers and buds of female hemp plant. The existence of the plant has been reported as early as 1500-1200 BC. in China, and cannabis has been described as an analgesic as early as 200 AD . Since then, an overwhelming number of studies have attempted to explain the physical and psychological effects of cannabis on humans. Physical Effects Physically, cannabis is relatively harmless. Studies have observed interestin