Rehab 4 Addiction

Withdrawal syndrome is the name for the condition caused by quitting substances.

When someone uses addictive substances for long periods, it causes lasting changes in the brain.

If an individual who has been using substances heavily stops using substances, especially in an abrupt fashion, the brain will go into withdrawal. This means that it is forced to rapidly adjust to being without the addictive substance.

Withdrawal syndrome includes a number of withdrawal symptoms, which vary in severity depending on a number of factors.

These factors are:

  • How dependent the individual was on substances when they stopped using them
  • What substance they were using
  • Whether they were using multiple substances
  • How long the individual spent using substances
  • Whether the individual has any complicating medical problems

Withdrawal syndrome can last anywhere from a few days to a few weeks, depending on the above factors.

It can be caused by legal/prescription drugs, as well as illicit ones.

Managing withdrawal symptoms

When someone stops taking substances under medical care, the doctor will help them to manage withdrawal symptoms. One way to ease withdrawal symptoms is by prescribing drugs like benzodiazepines, which are used for alcohol withdrawal.

During a home detox, individuals are left to manage withdrawal symptoms on their own. This can make withdrawal syndrome much more difficult to deal with.

Whether someone detoxes at home, or under medical care, acute withdrawal symptoms should be over after two weeks.

However, in some cases, post-acute withdrawal symptoms can occur after the initial period of withdrawal.

Post-acute withdrawal symptoms can last for as long as a year, and include psychological symptoms such as brain fog and fluctuating moods, as well as physical symptoms such as insomnia.

What is post-acute withdrawal syndrome?

Post-acute withdrawal syndrome, or PAWS, refers to the symptoms of withdrawal which continue after the initial phase. Though not as physically uncomfortable as acute withdrawal symptoms (such as nausea, vomiting, sweating etc.) these post-acute withdrawal symptoms can still pose a risk to an individual’s continued abstinence.

Knowing the symptoms of PAWS, and techniques to deal with them, can be very useful for someone who has recently stopped using substances.

PAWS is often said to come in waves: you may go through a long period without any symptoms, and then suddenly experience PAWS symptoms which last for a few days.

What are the most common symptoms of PAWS?

There is a lot of variance in how people experience PAWS, but some common symptoms include:

  • Anxiety
  • Chronic pain with no apparent source
  • Depression
  • Irritability
  • Inability to focus or think clearly
  • Low energy and fatigue
  • Mood swings
  • Poor sleep and insomnia
  • Reduced sex drive

If you are experiencing any of these symptoms, and you think you may be suffering from PAWS, speak to your doctor.

What substances cause PAWS?

PAWS is not limited to specific substances, and, in theory, can occur with any substance. However, it has been linked with the following substances:

  • Stimulants such as amphetamines can cause PAWS if someone stops taking them abruptly. Typical PAWS symptoms for stimulants include depression and insomnia
  • Not only do opioids cause severe withdrawal symptoms, especially when the individual stops taking them abruptly, they can also lead to PAWS. Opioid PAWS symptoms include cognitive impairment, tiredness and cravings
  • Cannabis. Cannabis is often used for self-medicating purposes, as it provides a short-term relief from conditions like anxiety. However, when someone stops using cannabis after building up a dependence, this can cause paranoia, depression and insomnia. [1] If untreated, this insomnia can persist, becoming a form of PAWS
  • Benzodiazepines. Benzodiazepines are prescribed for panic and anxiety. They are also highly addictive, for which reason they are not recommended for long-term use (the normal prescription is for 2 weeks). When someone stops taking benzodiazepines, especially without a taper, it can cause withdrawal. Not only that, but PAWS can follow the acute withdrawal phase, leading to tiredness and insomnia
  • Antidepressants are used to stabilise levels of serotonin in the brain. When someone stops taking this form of medication abruptly, it can cause withdrawal that lasts for months. During this withdrawal phase, the individual will feel very depressed
  • Alcohol. Alcohol can cause very severe withdrawal symptoms. Some develop a condition called delirium tremens, which is characterised by hallucinations. Alcohol can also cause PAWS. The typical symptoms of alcohol-induced PAWS are tiredness, cravings and brain fog

What evidence is there for the existence of PAWS?

Though PAWS has been the subject of some research, it is yet to be recognised in the Diagnostic and Statistical Manual of Mental Disorders, which is the most reputable reference book for addiction and mental health.

So, is PAWS real? What evidence is there that it exists?

One study, by S L Satel et al., looked at clinical data and laboratory research regarding withdrawal from alcohol, opiates and stimulants. It argued that there is insufficient evidence to recommend PAWS for inclusion in the DSM-IV (the penultimate edition of the reference book cited above).

The reason given by Satel et al. was this:

‘Symptoms extending beyond the period of acute withdrawal in alcohol and opiate dependence have been fairly consistently described. Nevertheless […] There is insufficient documentation to justify inclusion of protracted withdrawal in DSM-IV because of methodologic limitations of the studies and lack of consensus definition of the term itself.’ [2]

In essence, then, PAWS has been described by many people in recovery but has yet to receive sufficient scientific study to be accepted by the medical community.

What causes PAWS?

Just as the existence of PAWS has been the subject of some controversy in the scientific community, there is still debate around the causes of PAWS.

One of the difficulties is that PAWS seems to vary so much from person to person. If PAWS had a set of very consistent symptoms, perhaps it would be easier to isolate a specific cause.

However, symptoms are not consistent, and are liable to come and go, such that individuals in recovery may experience PAWS symptoms for a few days and then be symptomless for months.

One point on which scientists seem to agree, by and large, is that the stress response plays an important part in the development of PAWS. However, as we will see, there is disagreement about what triggers the stress response.

Perhaps the simplest explanation for PAWS is that the very experience of giving up a substance causes stress, and this stress makes psychological symptoms of withdrawal worse. Relapse leads to more stress, which keeps the cycle of withdrawal symptoms and PAWS symptoms going.

Another explanation for PAWS is that it is caused by changes in habits. On this understanding, stress is caused by the loss of certain habits built up during a period of substance use. The loss of these habits, coupled with the associated stress of habit-loss, leads to an exacerbation of psychological symptoms such as depression and tiredness.

A third explanation focuses on changes in the body. The body gets used to a steady supply of drugs or alcohol; it takes time to readjust, leading to withdrawal symptoms. This is often the explanation given for acute withdrawal symptoms; however, it might also explain PAWS in some cases. For example, someone who was addicted to CNS depressants might find that their heart rate takes longer than two weeks to return to normal.

A fourth, and final explanation focuses on changes in the brain. Substance use leads to changes in the brain which cannot be undone immediately; there may be long-lasting changes which take months to go back to normal. If this is the case, it would go some way towards explaining psychological symptoms like mood swings which are typical of PAWS. Click here for more information about changes in the brain and how they impact the ability to cope with stress.

How to treat PAWS

Given that PAWS symptoms are mainly psychological, treatment focuses on how to cope with these psychological symptoms and prevent them from leading to relapse.

Some suggestions for treatment include:

  • Be patient. PAWS takes a long time to go away, but it will go away eventually.
  • Celebrate milestones in the recovery process.
  • Doctors: make sure that individuals going through PAWS understand why they are experiencing these symptoms.
  • Focus on good nutrition and regular exercise. Both have been proven to improve mental health. [3]
  • Insomnia is a common part of PAWS. Rather than using medication to help you sleep, try natural remedies. Sleeping pills can be a dangerous route to go down.
  • Support groups can provide valuable companionship and solidarity with people in similar situations.
  • Use relapse prevention techniques to avoid the threat of relapse.
  • Watch out for co-occurring disorders. They can complicate withdrawal symptoms and lead to stress and anxiety when undiagnosed.


[1] Budney AJ, Hughes JR, Moore BA, Vandrey R. Review of the validity and significance of cannabis withdrawal syndrome. Am J Psychiatry. 2004 Nov;161(11):1967-77. doi: 10.1176/appi.ajp.161.11.1967. PMID: 15514394.

[2] Satel SL, Kosten TR, Schuckit MA, Fischman MW. Should protracted withdrawal from drugs be included in DSM-IV? Am J Psychiatry. 1993 May;150(5):695-704. doi: 10.1176/ajp.150.5.695. PMID: 8097618.

[3] The Influences of Diet and Exercise on Mental Health Through Hormesis. Fernando Gomez-Pinilla


Boris is our editor-in-chief at Rehab 4 Addiction. Boris is an addiction expert with more than 20 years in the field.  His expertise covers a broad of topics relating to addiction, rehab and recovery. Boris is an addiction therapist and assists in the alcohol detox and rehab process. Boris has been featured on a variety of websites, including the BBC, Verywell Mind and Healthline.