How Depressants Affect Your Body

glass of alcohol on the rocks
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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 (nerve cells) in the CNS, which leads to symptoms such as drowsiness, relaxation, decreased inhibition, anesthesia, sleep, coma, and even death. Many depressant medications 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.

This article discusses the different types of depressants and how they are used. It also explores how these medications work, when they should be taken, and potential risks.

Types of Depressants

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 drug 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 (SAMHSA) found that nearly 61 million people in the U.S. over the age of 12 reported being binge alcohol users.

The National Institute on Alcohol Abuse and Alcoholism (NIAAA) defines binge drinking as a pattern of alcohol consumption that brings blood alcohol concentration (BAC) to 0.08% or higher. Another 16 million people over the age of 12 reported being heavy alcohol users.

Alcohol use and abuse also has high social costs. Statistics suggest that approximately 50% of all assaults, homicides, and highway deaths involve alcohol. One-third of all U.S. suicides involve alcohol.

Barbiturates

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 (rapid eye movement) sleep. Because the potential for addiction and overdose is so high, barbiturates are no longer commonly used to treat anxiety and sleep problems.

Benzodiazepines

Benzodiazepines are a type of CNS depressant that has have sleep-inducing, sedative, muscle-relaxing, and anticonvulsant effects. The most commonly prescribed benzodiazepines are Valium, Xanax, Halcion, Ativan, and Klonopin. 

Benzodiazepines have been used to treat a number of issues including sleep difficulties, anxiety, excessive agitation, muscle spasms, and seizures. According to the National Institute on Drug Abuse (NIDA), benzodiazepine use increased by 67% in the U.S. between the years 1996 and 2013.

Because of their low toxicity and high effectiveness, benzodiazepines have been used as a short-term treatment for anxiety problems and insomnia. However, the potential for dependency makes them a less preferred long-term treatment.

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

Uses

Depressant drugs include hypnotics, tranquilizers, and sedatives. Because these drugs slow brain activity, they can be helpful for treating acute stress, anxiety, panic, and sleep disorders. Depressants are often used to relieve symptoms associated with a number of different disorders, including:

How Depressants Work

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.

In addition to causing feelings of drowsiness or sleepiness, it is also common for people taking depressants to experience:

  • Decreased blood pressure
  • Disorientation or confusion
  • Dizziness
  • Poor coordination
  • Memory loss
  • Slowed breathing and heart rate
  • Slurred speech

When people first start taking depressants, they often experience feelings of excess sleepiness until their body adjusts to the medication.

Who Should Take Depressants?

People should take depressants if they have been advised to do so by their healthcare provider. These medications can be safe and effective when they are used as prescribed. 

A healthcare provider might prescribe a depressant medication to treat a condition such as anxiety, panic, acute stress, seizure disorders. sleep disorders, convulsions, or panic attacks. In some cases, such as when treating anxiety, these medications might be used alongside psychotherapy.

Potential Pitfalls of Taking Depressants

Depressants have the potential for misuse and dependence. Sometimes people misuse these medications intentionally, but dependence can occur after taking these medications as prescribed for an extended period of time.

When a person takes CNS depressants, their body builds a tolerance to the medication. As a result, people have to take more of the medication to continue experiencing the same benefits. Over time, these higher doses can lead to dependence. 

What Is Dependence?

Dependence means that a person needs to keep taking a medication in order to avoid experiencing symptoms of withdrawal. 

If a person has become dependent on a CNS depressant, they may experience significant, unpleasant withdrawal symptoms if they suddenly stop taking it. Symptoms of withdrawal can include:

  • Anxiety
  • Hallucinations
  • Increased blood pressure
  • Irritability
  • Nausea
  • Rapid heartbeat
  • Restlessness
  • Seizures
  • Shaking

These symptoms can be minimized or avoided by slowly reducing the dose of the medication over a period of time to gradually wean off the substance.

Depressants can also lead to overdose if too much of the substance is taken or it is combined with another substance. When people overdose on depressants, their breathing slows or even stops. This can lead to coma, brain damage, or death. 

Summary

Depressants are drugs that affect neurotransmitters in the central nervous system. They slow brain activity to induce feelings of drowsiness, relaxation, and pain relief. Common types of antidepressants include alchohol, barbiturates, and benzodiazepines.

Some types of depressants may be prescribed to treat conditions including stress, anxiety, sleep disorders, and seizures. These medications can be safe and effective, but they do have a risk for tolerance, dependence, and overdose.

A Word From Verywell

If you are prescribed depressants for a health condition, it is important to always take your medication exactly as prescribed. Doing so can help minimize the risk for dependence. However, dependence may occur even if you take you medication as prescribed if you take depressants for an extended period of time.

If you want to stop taking your medication, always talk to your healthcare provider first in order to minimize the risk of serious withdrawal effects.

10 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Institute on Alcohol Abuse and Alcoholism. Alcohol facts and statistics.

  2. National Institute on Drug Abuse. How do CNS depressants affect the brain and body?.

  3. McMurran M. Alcohol-Related Violence: Prevention and Treatment. Wiley.

  4. Kaplan MS, Huguet N, McFarland BH, et al. Use of alcohol before suicide in the United StatesAnn Epidemiol. 2014;24(8):588-592.e5922. doi:10.1016/j.annepidem.2014.05.008

  5. National Institute of Drug Abuse. What are prescription CNS depressants?.

  6. Drug Enforcement Administration. Benzodiazepines.

  7. National Institute of Drug Abuse. Benzodiazepines and opioids.

  8. Olfson M, King M, Schoenbaum M. Benzodiazepine use in the United States. JAMA Psychiatry. 2015;72(2):136-42. doi:10.1001/jamapsychiatry.2014.1763

  9. Zlott DA, Byrne M. Mechanisms by which pharmacologic agents may contribute to fatigue. PM R. 2010;2(5):451-5. doi:10.1016/j.pmrj.2010.04.018

  10. Drug Enforcement Administration. Depressants.

Additional Reading

By Kendra Cherry
Kendra Cherry, MS, is an author and educational consultant focused on helping students learn about psychology.