What Are Depressants?

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. Many 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 significant differences among substances within this drug class. Some are safer than others and several are routinely prescribed for medicinal purposes.

Drugs that are classed as depressants include:

• Ethyl alcohol
• Barbiturates
• Benzodiazepines

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. A 2014 survey conducted by the Substance Abuse and Mental Health Services Administration found that nearly 61 million people in the U.S. over the age of 12 reported being binge alcohol users. Another 16 million people over the age of 12 reported being heavy alcohol users.

Alcohol use and abuse also have 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 small 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 overdose is so high, barbiturates are no longer commonly used 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, the 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).

Benzodiazepines have sleep-inducing, sedative, muscle-relaxing, and anticonvulsant effects. Because of these effects, benzodiazepines have been used to treat a number of issues including sleep difficulties, anxiety, excessive agitation, muscle spasms, and seizures.

Benzodiazepines are generally viewed as safe in the short-term, but long-term use can lead to tolerance, dependence, and withdrawal symptoms upon cessation.

Depressants are often used to relieve symptoms associated with a number of different disorders, including:

• Anxiety, including social phobia, panic disorders, and general anxiety disorder
• Obsessive-compulsive disorder
• Depression
• Insomnia
• Seizures

Many CNS depressants work by increasing the activity of the neurotransmitter known as gamma-aminobutyric acid (GABA). Like other neurotransmitters, GABA carries messages from one cell to another. By increasing the amount of GABA activity, brain activity is reduced, leading to a relaxing effect. This is why taking depressants can result in feelings of drowsiness.