Someone who has smoked a single marijuana cigarette may be in a talkative, outgoing mood and have food cravings. This is often followed by a period of sleepiness. Users often show signs of paranoia. Marijuana also impairs coordination, concentration, and short-term memory. Heavy users may smoke several marijuana cigarettes a day.
High doses can produce hallucinations.
Long-term use may lead to a lack of energy, motivation, and impairment of memory. These effects may linger even after the user stops using the drug. In recent studies, scientists at the University of California, Los Angeles, have found that daily inhalation of one to three marijuana cigarettes appears to produce approximately the same lung and cancer risks as smoking five times as many tobacco cigarettes. As with tobacco, lung damage and the risk of cancer are significant hazards of marijuana use. It is important to convey clear and consistent messages about drugs and drug abuse.