Cannabis, also known as marijuana among other names,[a] is a psychoactive drug from the Cannabis plant used primarily for medical or recreational purposes. The main psychoactive component of cannabis is tetrahydrocannabinol (THC), which is one of the 483 known compounds in the plant, including at least 65 other cannabinoids. Cannabis can be used by smoking, vaporizing, within food, or as an extract.
Cannabis has mental and physical effects. It causes a “high”, or stoned feeling and other effects, including a general change in thought and perception, difficulty concentrating, impaired short-term memory, altered sense of time, impaired body movement, relaxation, and an increase in appetite (otherwise known as “munchies”.) Onset of effects is felt within minutes when smoked, and about 30 to 60 minutes when cooked and eaten. The effects last for two to six hours, depending on the amount used. At high doses, mental effects sometimes include psychosis, delusions, hallucinations, paranoia, and ideas of reference, sometimes with anxiety and panic. Its physical effects include increased heart rate, difficulty breathing, nausea, and behavioral problems in children whose mothers used cannabis during pregnancy. Short-term side effects may include a dry mouth, red eyes, and feelings of paranoia or anxiety. Long-term adverse effects may include addiction, decreased mental ability in those who started regular use as adolescents, chronic coughing, and susceptibility to respiratory infections. There is a strong relation between cannabis use and the risk of psychosis, though the cause and effect is debated.