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Drug Facts

Central Nervous System (CNS) Depressants

What Are CNS Depressants?

A pile of prescription drugs.Central nervous system (CNS)—the brain and spinal cord—depressants slow down (or "depress") the normal activity that goes on in the brain. Doctors often prescribe them for people who are anxious or can't sleep. When taken as directed, they can be safe and helpful. But when people take someone else's prescription drugs or take the drugs for entertainment or pleasure, they may experience dangerous consequences.

CNS depressants can be divided into three primary groups:

CNS Depressants
Type Conditions They Treat Street Names
Barbiturates
  • Mephobarbital (Mebaral)
  • Sodium pentobarbital (Nembutal)
  • Seizure disorders
  • Surgical procedures
Barbs, reds, red birds, phennies, tooies, yellows, or yellow jackets
Benzodiazepines
  • Diazepam (Valium)
  • Alprazolam (Xanax)
  • Estazolam (ProSom)
  • Acute stress reactions
  • Panic attacks
  • Convulsions
  • Sleep disorders
Candy, downers, sleeping pills, or tranks
Sleep Medications
  • Zolpidem (Ambien)
  • Zaleplon (Sonata)
  • Eszopiclone (Lunesta)
  • Sleep disorders
A-minus or zombie pills

Facts on CNS Depressants [PDF - 456 KB]

Facts on Prescription and Over-the-Counter Drugs [PDF - 492 KB]

How Are CNS Depressants Abused?

CNS depressants usually come in pill or capsule form. A person who abuses them might take a CNS depressant not prescribed for them, take more than prescribed, or take them for reasons other than prescribed. Sometimes people take CNS depressants with other drugs or to counteract the effects of other drugs, such as stimulants.

How Do CNS Depressants Affect the Brain?

Most CNS depressants affect the brain in the same way—they enhance the activity of gamma-aminobutyric acid (GABA), a naturally occurring chemical in the brain that sends messages between cells. GABA works by slowing down brain activity. Although different classes of CNS depressants work in unique ways, they ultimately increase GABA activity, which produces a drowsy or calming effect.

What Negative Effects Can Be Associated With CNS Depressants?

Although CNS depressants can help people suffering from seizures, anxiety, or sleep disorders, they can be addictive and should be used only as prescribed. Addiction is when a person compulsively seeks out and uses a drug despite known harmful consequences. During the first few days of taking a CNS depressant, a person usually feels sleepy and uncoordinated. With continuing use, the body becomes accustomed to these effects, and they lessen. This is known as tolerance, which means that larger doses are needed to achieve the same initial effects. Continued use can lead to physical dependence and, when stopped, withdrawal.

CNS depressants should not be combined with any medication or substance that causes drowsiness, including prescription pain medicines, certain over-the-counter cold and allergy medications, or alcohol. If combined, they can slow both the heart and respiration, which can lead to death.

What Happens When You Stop Taking CNS Depressants?

Abuse of high doses of CNS depressants can lead to physical dependence and, when reduced or stopped, serious withdrawal symptoms. CNS depressants work by slowing the brain's activity, so when someone stops taking a CNS depressant, activity in the brain can rebound and race out of control to the point that seizures can occur. Someone who is either thinking about discontinuing use, or who has stopped and is suffering withdrawal, should seek medical treatment.

Are There Treatments for Addiction to CNS Depressants?

Counseling in an inpatient or outpatient setting can help people overcome addiction to CNS depressants. For example, cognitive behavioral therapy has been used successfully to help people in treatment for abuse of benzodiazepines. This type of therapy focuses on helping to change a patient's thinking, expectations, and behaviors while simultaneously increasing their skills for coping with various life stressors.

What Can I Do?

When someone you care about has a drug problem, it's not always easy to know what to do. If someone you know is abusing or misusing prescription drugs, encourage him or her to talk to a parent, school guidance counselor, or other trusted adult. There are also anonymous resources, such as the National Suicide Prevention Lifeline (1-800-273-TALK) and the Treatment Referral Helpline (1-800-662-HELP).

The National Suicide Prevention Lifeline (1-800-273-TALK) is a crisis hotline that can help with a lot of issues, not just suicide. For example, anyone who feels sad, hopeless, or suicidal; family and friends who are concerned about a loved one; or anyone interested in mental health treatment referrals can call this Lifeline. Callers are connected with a nearby professional who will talk with them about what they're feeling or about concerns for family and friends.

In addition, the Treatment Referral Helpline (1-800-662-HELP)—offered by the Substance Abuse and Mental Health Services Administration—refers callers to treatment facilities, support groups, and other local organizations that can provide help for their specific needs. You can also locate treatment centers in your state by going to www.samhsa.gov/treatment.