An introduction to drug classes notes that with the exception of anabolic steroids, drugs in the other classes are used to alter mood, thought, and feeling through their actions on the central nervous system. In addition to having abuse potential (used in a manner or amount inconsistent with the medical or social patterns of a culture), most controlled substances are capable of producing dependence, either physical or psychological. The section on "narcotics" divides these drugs into the following categories: narcotics of natural origin (opium, morphine, codeine, and thebaine); semi-synthetic narcotics (heroin, hydromorphone, oxycodone, and hydrododone); synthetic narcotics (meperidine); and narcotics treatment drugs (methadone, dextoproxyphene, fentanyl, pentazocine, and butorphanol). The second category of drugs mentioned is "depressants," which encompasses various barbiturates. The section on "stimulants" focuses on cocaine, amphetamines, and anorectic drugs (khat). The drugs classified as "cannabis" include marijuana, hashish, and hashish oil. Drugs classified as "hallucinogens" are LSD, psilocybin and psiocyn and other tryptamines, peyote and mescaline, MDMA (Ecstasy and other phenethylamines), phencyclidine and related drugs, and ketamine. Other drugs reviewed are steroids and inhalants. Listings of domestic DEA offices and drug-related coordinators and administrators in the National Guard