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What Are Depressants?


What Are Depressants?

Hand holding bourbon filled glass at a bar.

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Depressants are drugs that inhibit the function of the central nervous system (CNS) and are among the most widely used drugs in the world. These drugs operate by affecting neurons in the CNS, which leads to symptoms such as drowsiness, relaxation, decreased inhibition, anesthesia, sleep, coma, and even death. All depressants also have the potential to be addictive.

While CNS depressants all share an ability to reduce activity in the central nervous system and lower levels of awareness in the brain, there are important differences among substances within this drug class. Some are safer than others, while others have more potential for use for medicinal purposes.

Drugs that are classed as depressants include:

  • Ethyl alcohol
  • Barbiturates
  • Benzodiazepines

Ethyl Alcohol

Alcohol, also known as ethyl alcohol, is the second most widely used psychoactive drugs in the world (caffeine is number one). While alcohol is a legal drug, it also has a high potential for abuse. One survey conducted by the Substance Abuse and Mental Health Services Administration found that nearly 70 million over the age of 12 reported participating in binge drinking or heavy drinking (2002). Alcohol use and abuse also has high social costs. According to the American Psychiatric Association, approximately 50 percent of all assaults, homicides, and highway deaths involve alcohol (2000).


Barbiturates, sometimes referred to as downers, are a type of CNS depressant that causes euphoria and relaxation when taken in low doses. During the early half of the 1900s, barbiturates were viewed as a safe depressant, but problems with addiction and deadly overdoses soon became apparent. Barbiturates have a dramatic impact on sleep patterns, resulting in suppressed REM sleep. Because the potential for addiction and misuse is so high, barbiturates are commonly replaced with benzodiazepines to treat anxiety and sleep problems.


Benzodiazepines are a type of CNS depressant widely prescribed to treat anxiety and sleep disorders. In 1999, four different benzodiazepines were among the top 100 most prescribed drugs in the U.S. (Latner, 2000). Because of their low toxicity and high effectiveness, benzodiazepines have been popularly used as a short-term treatment for anxiety problems and insomnia. However, their potential for dependency makes them a less preferred long-term treatment for such things as generalized anxiety disorder, post-traumatic stress disorders, and panic disorders (Julien, 2001).


American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders. (4 ed., Text Revision). Washington DC: American Psychiatric Association.

Julien, R.M. (2001). A primer of drug action. New York: Worth Publishers.

Latner, A. (2000). The top 200 drugs of 1999. Pharmacy Times, 66, 16-32.

Substance Abuse and Mental Health Services Administration. (2002). The national household survey on drug abuse report. Found online at http://www.oas.samhsa.gov/nhsda/2k2nsduh/Overview/2k2Overview.htm#highlights

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