Drugs of abuse can be generally classified according to the effect that the drugs exert on the user. According to the National Clearing House for Alcohol and Drug Information, the major types of abused drugs include depressants, stimulants, inhalants, narcotics, hallucinogens, steroids and marijuana. Some drugs, such as cocaine, may fit into more than one category. Cocaine, for example, is considered a narcotic, but it is also a stimulant.
Depressants
Depressants are drugs that lower the activity of the nervous system. They are often prescribed to treat insomnia and anxiety disorders as described by the National Institute for Mental Health. Neuroscience textbooks generally classify depressants into two groups: barbiturates and benzodiazepines.
Stimulants
This class of drugs elevates the activity of the nervous system. The National Institute on Drug Abuse states that they are prescribed for the treatment of narcolepsy, attention deficit disorder and other disorders. Stimulants cause a user to feel energized and alert.
Inhalants
Inhalants are atypical "drugs" that have a nonmedical purpose, such as glue or gasoline. Inhaling the fumes of these substances causes the user to feel euphoric and drunk. Inhaling fumes is referred to as "huffing."
Narcotics
Narcotics include drugs of the opiate family, as well as cocaine and crack. Opiates are analgesic--they provide pain relief. Common opiates used in a clinical setting include morphine and codeine. Crack and cocaine have stimulatory effects but are classified by the U.S. Drug Enforcement Administration's Controlled Substances Act as narcotics.
Hallucinogens
Hallucinogens are drugs that affect the sensory systems and cause the user to have an altered perception of reality, sometimes in the form of hallucinations. Hallucinogens include the drugs known as "angel dust," or PCP, ecstasy and "acid," or LSD.
Steroids
Steroids are substances that have a particular molecular arrangement and include certain hormones as well as legal and illegal drugs. The MayoClinic.com states that some steroids may be prescribed to treat inflammation or dampen the response of the body's immune system. Prednisone is one example of a steroid used for these purposes. Another type of steroid, anabolic steroids, are sometimes illegally used by athletes to promote increased muscle mass.
Cannabinoids
Cannabinoids include marijuana, hashish and THC. All of these are derived from the Cannibis sativa, or hemp, plant. The National Institute on Drug Abuse cites marijuana as the the most commonly used illegal drug. Users experience a sense of euphoria and relaxation.
References
- U.S. Drug Enforcement Administration
- "Molecular Neuropharmacology; A Foundation for Clinical Neuroscience (2nd Edition)"; Eric Nestler, Seven Hyman and Robert Malenka; 2009
- National Clearinghouse for Alcohol and Drug Information: Drugs of Abuse
- National Institute of Mental Health: Treating Anxiety Disorders
- National Institute on Drug Abuse: Prescription Drug Abuse Chart
