marijuana. Clinical Information. Excessive use of marijuana with associated psychological symptoms and impairment in social or occupational functioning. Marijuana is a dry, shredded mix of flowers, stems, seeds and leaves of the hemp plant cannabis sativa. People usually smoke it as a cigarette or in a pipe.
People usually smoke it as a cigarette or in a pipe. It is the most commonly abused illegal drug in the United States.abusing marijuana can result in problems with memory, learning and social behavior. It can interfere with family, school, work and other activities.