The Science of Marijuana: Just the Facts

A continuation in the series Cannabis, Coca, and Poppy: Nature’s Addictive Plants.

This presentation by Susan Weiss, Ph.D., Office of Science Policy and Communications, National Institute on Drug Abuse (NIDA), highlights what we know and what we don’t about marijuana’s effects on the brain and the body. The use of marijuana can produce adverse physical, mental, emotional, and behavioral changes, and—contrary to popular belief—it can be addictive. Marijuana smoke, like cigarette smoke, can harm the respiratory system. The use of marijuana can impair short-term memory, verbal skills, and judgment, and distort perception. Because marijuana affects brain systems that are still maturing during young adulthood, use by young teens may have a negative effect on development.