What is central nervous system (CNS) depression?

What is central nervous system (CNS) depression?

CNS depression is a type of depression caused by the abuse of CNS inhibitors. CNS inhibitors are substances that can slow down the central nervous system. Some common examples include opioids, sedatives, and hypnotics. These drugs are used to treat pain, anxiety, sleep disorders, and stress. The central nervous system is composed of the brain and spinal cord, which controls blood circulation and digestion.

CNS inhibitors work by increasing the activity of a neurotransmitter called gamma-aminobutyric acid (GABA) in the brain. The increase in GABA activity in the brain will cause the brain activity to slow down. Central nervous system depression is especially common in people who use these substances recreationally.

The severity of depression in the central nervous system varies. You may experience severe central nervous system depression due to the use of central nervous system depressants or abuse of central nervous system depressants, traumatic brain injury, or certain other conditions.

Symptoms of Central Nervous System (CNS) Depression

People with central nervous system depression have different symptoms; two people with this disease may be different. Some of the most common but mild symptoms that can help identify the condition include:

  • Slurred speech
  • Unresponsive
  • Higher pain tolerance
  • drowsiness
  • Headache
  • dizzy

When the severity of the condition worsens, a person will experience more severe symptoms, some of which include:

  • Puzzled
  • Extreme fatigue
  • Difficulty breathing
  • Difficulty staying awake
  • Fingers and lips start to turn blue
  • Low blood pressure
  • Memory problem


People who use central nervous system depressants may sometimes experience mild depression as a side effect. This usually goes away when you stop using the medicine or when your body adjusts to the medicine.

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Before making a diagnosis of central nervous system depression, your doctor will need to review your medical history and perform a series of tests. If you have recently taken a CNS inhibitor or abused any CNS inhibitor, this will be the most likely culprit.

Another major cause of central nervous system depression in people without a history of central nervous system depressants is brain damage. If your doctor suspects that a brain injury or tumor is the cause of your depression, they may order a CT scan, an MRI scan, or both.


The abuse of certain substances can lead to central nervous system depression. These substances are called CNS inhibitors because they affect the activity of your CNS. People either abuse the central nervous system depressants by taking more than the prescribed amount, or take them without prescribed to change their minds. The most common substances that cause central nervous system depression include:

  • Opioids: Opioids are powerful analgesics extracted from opioids such as heroin and oxycodone. They have a high risk of addiction, which is why they are usually only taken in small doses for a short period of time. Opioids are often abused and used for entertainment, making them one of the main causes of depression in the central nervous system. Some common types of opioids commonly used to treat severe pain include Vicodin and Percocet.
  • Alcohol: Although many people don’t think that alcohol is a drug, it is one of the most common and abused drugs in the world today. Alcoholism can lead to addiction and central nervous system depression.
  • Barbiturates: Barbiturates are drugs commonly used to treat anxiety and sleep disorders. Some of the most common types include Luminal, Amytal, and Nembutal. Barbiturates are powerful drugs. Over time, medical professionals have switched from using them to treat anxiety and sleep disorders to using them as anticonvulsants (anti-epileptics).
  • Benzodiazepines: Benzodiazepines, also known as Benzos, are also used to treat anxiety and sleep disorders, although they are considered less addictive than barbiturates. Xanax, Valium, and Prosom are some of the most common benzodiazepines.
  • Sleeping pills: Central nervous system depressants slow down brain activity, making them a good way to treat sleep disorders. Sonata and Ambien are two types of sleeping pills, which are central nervous system depressants. Although they have a lower risk of dependence compared with other central nervous system depressants, long-term use may cause this condition.

In some cases, stroke, brain injury, aneurysm or tumor may also cause central nervous system depression. Some studies have shown that even diseases that do not directly affect the brain, such as diabetes or kidneys and heart disease, can cause central nervous system depression.

The combined use of one or more CNS inhibitors usually results in CNS inhibition. In these cases, alcohol is usually the culprit. This is why these drugs specifically prohibit you from drinking alcohol while taking them.

People with a history of drug or alcohol dependence are at greater risk of developing severe central nervous system depression, which is why doctors will thoroughly check your medical history before prescribing a central nervous system depressant for any condition.


The treatment of depression in the central nervous system depends on its cause. If it is caused by the misuse of central nervous system depressants, certain drugs will be prescribed.

  • Naloxone: Naloxone is used for people who overdose on opioids. It can be administered as an injection or intravenously.
  • Flumazenil: Flumazenil is suitable for people who have serious side effects due to the use of benzodiazepines. Flumazenil is also used to treat drug overdose. However, it is a short-acting drug and may require multiple doses to recover.

If severe central nervous system depression is not treated, it can be fatal for people with this disease.


Mild central nervous system depression usually does not need to be worried. The central nervous system depressant works by slowing down brain activity, which is why it is very useful for diseases such as anxiety and sleep disorders. However, if you find that your central nervous system depressants affect your daily functions, please consult your doctor. They will decide if you need to stop the medication, switch to another medication, or if you need to adjust the dose.

However, severe central nervous system depression requires immediate treatment, otherwise it may lead to heart failure or even death. If you are taking a central nervous system depressant and suspect it is making you more drowsy than you should, please do not stop taking it before talking to your doctor. Stopping the drug suddenly may do more harm than good.

Mild central nervous system depression is usually the target of taking some central nervous system depressants, especially sleep and anxiety disorders. It is important to take the medicine exactly as prescribed by the doctor to avoid more serious conditions. Once you experience any side effects that you think are intolerable, it is best to notify your doctor immediately.