Antidepressant - A major classification of drugs used medically to improve mood in severely depressed patients. Included are the tricyclic compounds, Amitriptyline (Alluvial) and Imipramine (Trofranil). These are rarely used for nonmedical purposes, as they have little immediate pleasurable effect on normal mood states.

Opiates - a major class of drugs that depress the central nervous system and are used principally to relieve pain. Examples include morphine, heroin, and codeine.

Marijuana - also called weed, pot, reefer, grass, dope, ganja, mary jane and hash is the drug most often used in this country. It is a mix of dried, shredded flowers and leaves of the hemp plant. Most users roll loose marijuana into a cigarette. Hash users either smoke the drug in a pipe or mix it with tobacco and smoke it as a cigarette.