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Post-Acute Withdrawal Syndrome or PAWS—Symptoms and Treatment

What Is Post-Acute Withdrawal Syndrome or PAWS?

Post-acute withdrawal syndrome is a collection of symptoms experienced by some individuals struggling with alcohol and drug addiction after a prolonged period of withdrawal.1 The syndrome is also known by several similar terms, including PAWS, post-withdrawal, protracted withdrawal, prolonged withdrawal syndrome, and protracted abstinence.

Post-acute withdrawal syndrome is separate and distinct from the acute phase of withdrawal, which typically occurs in the first two weeks after drug cessation.

Acute withdrawal has long been studied by addiction researchers and—dependent on the type of drug from which withdrawal is occurring—is characterized primarily by physical symptoms. These symptoms may include:2

  • Tremors.
  • Seizures.
  • Autonomic nervous system hyperactivity (sweating, nausea, rapid heart rate).
  • Intense drug cravings.

How Long Does PAWS Last?

In contrast to acute withdrawal, symptoms of post-acute withdrawal syndrome generally occur 2 months or more after drug cessation and are primarily psychological in nature, affecting a person’s mood, sleep patterns, and response to stress. PAWS symptoms generally last for several months in people recovering from addiction, though they can disappear in a matter of weeks or, in rare cases, persist for a year or more.

Post-Acute Withdrawal Syndrome Symptoms

There is a myriad of long-term withdrawal symptoms associated with post-acute withdrawal syndrome.1,3 Though each of these is common among people withdrawing from drugs and alcohol, the exact number, combination, and timing of specific symptoms is different for each individual. Physical differences between people, as well as differences in the types of drugs used and the amounts and frequency of use, all affect a person’s experience of post-acute withdrawal syndrome.

  • Mood swings: The brain of a chronic drug user, including patients taking medications under their doctor’s supervision, becomes adapted to a constant supply of a mood-altering substance. When this substance is removed, periods of mania or depression can occur while the brain rebalances itself.
  • AnhedoniaAlthough they work in different ways, virtually all addictive drugs, and many medications like antidepressants, have the end result—in the short term, at least—of boosting neurotransmitters and neural pathways that make the user feel good. Once these drugs and medications are stopped, however, it can take some time for the brain to produce normal levels of these feel-good chemicals on its own again. Until it does, an individual may find that nothing seems fun or interesting anymore–even activities they used to enjoy.
  • AnxietyCessation of a drug or medication is a major life change. Therefore, it is understandable that there can be a great deal of anxiety, and even panic attacks, that accompany this shift. Additionally, drugs such as alcohol and benzodiazepines that chronically inhibit brain activity can result in a hyperexcitable state when use is stopped.
  • InsomniaMany psychoactive drugs and medications affect sleep patterns, and the brain adapts to long-term use. Once these drugs are stopped, it can take time to re-establish healthy sleep patterns.
  • Sleep disturbancesSubconscious desires to take alcohol or drugs, or to resume some aspect of the drug-using lifestyle, can manifest themselves in vivid, realistic dreams. Though such dreams may be disturbing to a person in recovery, they are not a warning of impending relapse, but simply a reflection of how deeply the drug-taking compulsion can be ingrained in the mind.
  • Cognitive impairmentLike mood changes, this is another symptom of neurotransmitter imbalance. It is important to remember that difficulties in thinking clearly and maintaining concentration are usually temporary and not a sign of permanent brain damage.
  • Depression and fatigue: Many people who stop chronic drug habits or long-term medications experience such intense feelings of depression and fatigue that they the fit the criteria for major depressive disorder or chronic fatigue syndrome. Unlike these conditions, however, these symptoms are a phase of readjustment in the brain and generally diminish without treatment over time.
  • Drug cravings: People with post-acute withdrawal syndrome often have intermittent cravings for the drugs or medications they took before. Because the most intense physical withdrawal symptoms have subsided, the individual may feel physically healthy but continue experiencing negative psychological symptoms, which can make a return to drug use seem appealing.
  • Sensitivity to stress: Many people dealing with the effects of post-acute withdrawal syndrome find that their threshold for daily stress is very low. Trivial irritations or setbacks can feel extremely intense. Considering that these individuals have given up what has been, for months or years, their primary tool for coping with life’s stresses, this difficulty is easy to understand. New life skills must be learned, and even dealing with normal emotions brought on by stress can take time.

These are some of the most common manifestations of post-acute withdrawal syndrome, but this is not a comprehensive list. One unifying theme among these symptoms is that they all impair various facets of an individual’s emotional state. Another common aspect of the symptoms is that they are intermittent and may come and go over days and weeks, and they generally do not impact a person to the same extent over the entire course of their withdrawal.

What Causes Post-Acute Withdrawal Syndrome?

A substance use disorder causes significant changes in the brain.1 These changes affect a person’s behaviors, thoughts, decision making, and emotions. When these changes in the brain continue long after the acute withdrawal period into post-acute withdrawal syndrome, pursuits such as dealing with stress and difficult situations and finding interest and joy in normal activities can become problematic.

Researchers believe certain drugs are the cause of post-acute withdrawal syndrome, and that they are more likely than others to trigger the condition. Alcohol has been studied the most, but drugs such as benzodiazepines, antidepressants, opioids, and psychostimulants have also been associated with PAWS.

Common Drug Classes Associated With Post-Acute Withdrawal Syndrome

Some classes of substances are more commonly associated with a protracted withdrawal period than others following relatively prolonged abstinence from the drugs.1,3 However, as previously noted, few rigorous scientific studies have been conducted into the etiology of post-acute withdrawal syndrome, so the following list of drugs that cause this syndrome is not exhaustive.

Because PAWS symptoms are thought to be caused by changes in brain function induced by psychoactive drugs that persist long after cessation of drug-taking, it is possible that any such drug, if taken long enough at a high enough dose, could result in post-acute withdrawal syndrome during the recovery process.


Of all drugs, prolonged withdrawal resulting from ceasing alcohol intake has received the most scientific attention. Studies examining symptoms now attributed to post-acute withdrawal syndrome have been published in medical journals since the 1990s.

Alcohol is a sedative drug and works, in part, by activating gamma-aminobutyric acid (GABA) receptors in the brain. Increased GABA activity inhibits, or decreases, brain activity overall, and the brain adapts to counteract chronic inhibition. An individual who has become dependent on alcohol will find that their nervous system is overactive, or hyperexcitable, when they stop drinking.

Initially, this hyperexcitable state can lead to seizures and tremors, but less severe symptoms such as sleep disturbances, mood swings, anxiety, and a lack of sexual interest can continue for several months or even years. Though gradually decreasing the amount of alcohol ingested over time, or tapering, can help reduce the intensity of acute withdrawal, this strategy appears to be much less effective for the longer-lasting symptoms of PAWS.


Similar to alcohol’s mechanism of action, benzodiazepines (BZDs)—such as diazepam (Valium) and alprazolam (Xanax)—are GABA receptor activators, and their chronic use also causes the brain to adapt by switching to a hyperexcitable state. Withdrawal symptoms are common with this class of drugs, even in patients who take them strictly as directed and under a doctor’s supervision.

As with alcohol, tapering can help acute benzodiazepine withdrawal, but it is not very effective for avoiding post-acute withdrawal syndrome. This can be very difficult for patients who have taken benzodiazepines for anxiety and panic disorders, since anxiety is a common symptom of post-acute withdrawal syndrome. Symptoms of protracted benzo withdrawal can look like symptoms of other disorders such as schizophrenia, depression, panic disorders, and obsessive-compulsive disorder (OCD).


Most modern antidepressant drugs are selective serotonin reuptake inhibitors (SSRIs)—such as fluoxetine (Prozac)—or serotonin-norepinephrine reuptake inhibitors (SNRIs)—such as venlafaxine (Effexor). They work to raise the levels of one or both neurotransmitters (serotonin and norepinephrine) in the brain by blocking their reabsorption by nerve cells.

The exact mechanism of how these drugs work to improve depression in patients is the subject of scientific debate, but almost certainly involves adaptive changes in the brain, since there is a delay of several weeks to a month before patients derive benefits from these medications. It is unsurprising, therefore, that long-term effects are commonly reported when patients stop taking their antidepressant medications.


Long-term symptoms of opiate withdrawal are commonly reported in individuals recovering from opioid addictions. Pharmaceutical and illicit opioid painkillers such as oxycodone (OxyContin), hydrocodone (Vicodin), codeine, and heroin, can elicit post-acute withdrawal syndrome symptoms like anxiety, fatigue, and sleep disturbances in dependent individuals when they stop taking these drugs.

All opioid drugs work by activating opiate receptors in the brain and spinal cord, which modulates perceived pain levels, induces a feeling of well-being, and produces, at high doses, a euphoric high. The body adapts to chronic overstimulation of opioid receptors by increasing the number of them on the surface of brain cells, so that more receptors need to be activated by opioid drugs to produce an effect.

Also, the number of endorphins—the natural chemicals that activate opiate receptors—is decreased in chronic opioid drug users as the body compensates for overstimulation of this system. These adaptations by the nervous system reduce opiate signaling to the brain and have been linked to increased pain sensitivity and mood disturbances in individuals addicted to opiates.

These changes can take months or even years to completely reverse themselves and for opiate signaling to return to normal levels. Some researchers have been experimenting with indirectly increasing opiate signaling in patients recovering from addiction with low-dose naloxone (Narcan) to alleviate PAWS symptoms.


Stimulant drugs—such as cocaine and amphetamine—provide some of the clearest evidence that post-acute withdrawal syndrome is a true medical condition and not simply an extension of acute withdrawal.

The psychological symptoms of post-acute withdrawal syndrome—such as paranoia, anxiety, impulse control problems, depression, and other emotional regulation issues—are frequently observed in chronic users who stop stimulants suddenly.

Similar to other drugs, these stimulant withdrawal symptoms are thought to be caused by adaptations in the brain to long-term stimulant use, and they can take several months or longer to resolve themselves.

Other Drugs

It is not certain that post-acute withdrawal syndrome is restricted only to certain classes of drugs.

It has been proposed that marijuana, antipsychotic medications, and anabolic steroids, in particular, can also induce post-acute withdrawal syndrome-like symptoms in those who stop taking these drugs after a period of chronic use.

Although the examples listed above reflect the most commonly encountered causes of post-acute withdrawal syndrome, the lack of recognition of this syndrome by medical societies and diagnostic guides means that many physicians are not looking for it in their patients and may miss it altogether.

Risk Factors for Post-Acute Withdrawal Syndrome (PAWS)

Individuals in recovery—even those with similar drug histories—report widely variable and unique experiences of post-acute withdrawal syndrome. Many factors can influence the types of post-acute withdrawal symptoms that manifest and the intensity with which they are experienced. These factors include:

  • Pattern of substance abuse.
  • Duration of the addiction.
  • Intensity of the drug use.
  • Genetics.
  • Physiology.
  • Psychological makeup.
  • Existence of other physical or psychological conditions.

History of drug use is the best-known risk factor for post-acute withdrawal syndrome. Those who have used psychoactive substances for longer, more often, and at higher doses are more likely to experience post-acute withdrawal symptoms, and the symptoms will be more intense than they are for those whose drug use was lighter.

Genetics and physiological factors are likely to play a role, however, since post-acute withdrawal syndrome can manifest differently in two individuals who have used the same substance in the same manner. Because so little research has been conducted into this syndrome, it is not possible to predict in advance how someone will be affected.

The Challenges of Post-Acute Withdrawal Syndrome

In addition to the subtle and unpredictable symptoms of post-acute withdrawal syndrome, individuals in recovery frequently experience challenges stemming from the fact that this syndrome is not universally recognized in the medical community, and little scientific research has been conducted into the causes of and treatments for this condition.

Though its existence is widely accepted among recovery professionals, post-acute withdrawal syndrome is not officially recognized by any medical associations, nor is it listed in the American Psychiatric Association’s Diagnostic Statistical Manual of Mental Disorders (DSM), the standard classification of mental disorders used by all mental health professionals in the United States.

What to Expect

Symptoms of PAWS will manifest themselves after the end of acute withdrawal, but they can appear anytime within several weeks to several months after drug cessation. The drug classes discussed above have different long-term effects on the brain, and the symptoms of post-acute withdrawal syndrome will be different depending on which substance, or combination of substances, was used.

Effects of this syndrome may then continue for anywhere from 2–3 months to several years. There are anecdotal reports of individuals who continue experiencing prolonged withdrawal for the rest of their lives, though this appears to be extremely rare.

It is important to remember that symptoms of post-acute withdrawal syndrome come and go. Most people do not experience excessive fatigue or anxiety for months or years on end without a break. Instead, these symptoms fluctuate, lasting days or weeks, and are separated by periods that are symptom-free.

How to Manage Post-Acute Withdrawal Syndrome

Though it can be upsetting, post-acute withdrawal syndrome is a normal part of the recovery process from dependence and addiction. It is important to be aware of the symptoms of prolonged abstinence from substance misuse, since some of these negative symptoms can be discouraging to recovering individuals and tempt them to return to drug use.

Steps that can be taken to manage post-acute withdrawal syndrome and improve your well-being during recovery include:1

  • Educating yourself. Become aware and educated about both acute and post-acute withdrawal so you know what to expect as you navigate the recovery process.
  • Focusing on positive changes and achievements. Although it is normal to focus on continued difficulties caused by post-acute withdrawal syndrome, you should not lose sight of how recovery is changing your life for the better.
  • Staying active. Physical activity and exercise help your body and brain heal more quickly—bolstering immune system activity and restoring healthy balance to neurotransmitter levels—and can reduce anxiety and stress, as well as help you sleep better in the long term.

Most importantly, be patient and take it easy on yourself. Though the experience of post-acute withdrawal syndrome can be unpleasant and frustrating for both the recovering person and their friends and family, these symptoms will subside with time. Patience and understanding are therefore the keys to successfully navigating post-acute withdrawal symptoms and learning how to live a healthy and happy life in recovery.

Find Addiction Treatment Programs

If you are struggling with addiction, help is available and recovery is possible. Rehab programs are located throughout the U.S, and many offer specialized treatment that can cater to individual needs. You can use SAMHSA’s Find Treatment tool to search for treatment centers. Many state government websites will provide local drug and alcohol resources to those in need. To find your state government’s website, do a web search for your state name and ‘.gov.’ Once your state website is located, substance use resources shouldn’t be hard to find, and they should provide further phone contacts for your assistance.

American Addiction Centers (AAC) is a leading provider of addiction treatment programs and has trusted rehab facilities across the country. Get started today by locating a treatment program near you or checking your health insurance coverage to find out what services may be covered. You can also call our 24-hour hotline free at .

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