What Is Withdrawal?

Symptoms of withdrawal range from sweatiness, shakiness, tremors, and seizures to upset stomach, diarrhea, and vomiting. Irritability, agitation, restlessness, and sleep disruption are common withdrawal symptoms for many drugs, as are muscle cramps, headaches, and changes in blood pressure and heart rate. Intense anxiety is common. Drug cravings can be fierce, and fear of withdrawal symptoms often drives continued drug use.

In his 2021 memoir of loss and addiction, Beautiful Things, Hunter Biden, son of President Joe Biden, described the symptoms vividly. “I was drinking now just to banish the ache of withdrawal. I felt lucky if I passed out. I’d be in such physical pain if I went any length of time without a drink that every joint in my body felt like it had been soldered shut. My anxiety spiked so high I’d wake up with the pillow soaking wet and the couch cushions drenched with sweat, as if someone had poured a bucket of water over me. I’d have chills and a fever until I threw down another drink. Then, for an instant, it would all go away. But that effect became harder and harder to achieve. If a shot of vodka gave me relief at the start, I soon required a tumbler, then a full Collins glass, then a full fifth, just to maintain some kind of equilibrium.”

In addition to the generalized symptoms of withdrawal, many substances produce withdrawal symptoms specific to their type of drug. With opiates, for example, those in withdrawal may experience bristling of body hairs, dilated pupils, yawning, and a runny nose.

Withdrawal starts after the active drug is cleared from the body (measured as “half-life,” the amount it takes for blood levels of the drugs to drop by 50 percent).

• Opiates: 6 hours to 2 days after last dose

• Benzodiazepines: 2 to 7 days after last dose, peaks around 2 weeks

• Alcohol: 6 hours to 2 days after the last drink, peaks 24 to 72 hours after the last drink

• Cocaine: 90 minutes after the last dose

• Methamphetamine: within 24 hours after the last dose, peaks at 7-10 days

Withdrawal symptoms occur when drug use is abruptly stopped or diminished. They occur because the brain is an adaptive organ (which permits learning of all kinds), and in response to the repeated presence of an externally introduced psychoactive substance, the brain adapts its operations around that substance. There are changes in neurotransmitter activity and receptor sensitivity in various brain systems. When use of that substance suddenly stops, all the adaptations to that substance the brain has made in multiple systems are caught short That kicks off a rebound of activity in numerous neurotransmitters and their receptors in many brain systems. The resulting symptoms constitute withdrawal, and the effects a person experiences are generally the opposite of those induced by the drug.

Both alcohol and benzodiazepine drugs are central nervous system depressants; abruptly stopping leads to nervous system excitation. In a small percentage of cases, especially following long periods of heavy alcohol use, withdrawal can be life-threatening, leading to seizures. Because it is not always possible to predict who will experience complications and who will not, medical supervision is generally advised for a period of detoxification. Detoxification typically involves individualized treatment with medications that mitigate the symptoms of withdrawal and diminish the risk of complications such as seizures.

For most other drugs, withdrawal is not medically dangerous; however, withdrawal can be acutely uncomfortable and set off extreme anxiety or depression in addition to physical discomfort. The resulting danger is that those addicted to a substance may continue using it merely to avoid the unpleasantness of withdrawal symptoms.

Medical care is not always needed in stopping substance use and the majority of those who quit do so on their own without enlisting any clinical services. However, for some addictions, there are specific medical treatments available that can ease the discomfort of withdrawal and minimize drug cravings. Studies show, for example, that treatment with the medication buprenorphine can significantly help opioid users quit. A partial opioid agonist, buprenorphine occupies opioid receptors in the brain, reducing drug cravings and preventing withdrawal symptoms. It is often used in conjunction with the opioid antagonist, naloxone., which blocks euphoric effects.

Medication-assisted treatment (MAT) does not, by itself, cure addiction, but it allows people to focus on and develop skills for sustained recovery and rebuilding a meaningful life. Buprenorphine treatment does not require hospitalization, can be prescribed by practicing physicians, and is typically available in conjunction with counseling and behavioral therapy.

Stopping alcohol consumption often brings on “the shakes,” or tremors, most noticeable as uncontrollable shaking in the hands. Tremors may begin 5-10 hours after the last drink and typically peak 24 to 78 hours after the last drink but can last for several weeks. Shakes reflect the fact that alcohol is a central nervous system depressant, and, over the course of substance use, to counteract the sedative effect of heavy alcohol consumption, some nerve circuits of the brain rev up their activity levels. In the immediate aftermath of discontinuing heavy alcohol use, the brain has not yet had time to adapt to the absence of alcohol. The neural hyperactivity, now unopposed by alcohol, creates the shakes, which decline as the brain accommodates to the absence of alcohol.

In general, acute withdrawal lasts about a week for drugs with a very short half-life. The opioid heroin is typical of such drugs. Its half-life is 2 to 6 minutes. Withdrawal begins 8-24 hours after the last dose, reaches a peak at 24-48 hours, and lasts 4-10 days. With prescription opiates, withdrawal symptoms begin in 8-12 hours, peak at 12-48 hours, and can last 5 to 10 days.

However, the opiate methadone is long-acting, and withdrawal follows a different course. Symptoms may begin in 2-4 days and fade after 10 days.

For drugs like amphetamine, with a medium half-life—10-12 hours—acute withdrawal can last 2-4 weeks. Withdrawal from amphetamine stimulants begins 2-4 days after the last dose, lasts 2-4 weeks or more. Its half-life is 9-11 hours.

For methamphetamine, with a half-life of 9-24 hours, withdrawal typically begins within 24 hours with a “crash,” a huge drop in energy and cognitive function. Symptoms peak at 7-10 days and subside in 2-3 weeks. But some of the psychological symptoms of meth withdrawal, such as anhedonia, the inability to experience pleasure, can last as long as two years, a measure of how long it can take for dopamine function to return to normal.

The stimulant cocaine has a very short half-life; acute withdrawal can begin as little as 90 minutes after the last dose, peaks around 3 days, and lasts a week to 10 days.

For drugs like short-acting benzodiazepine tranquilizers (Xanax, Valium, Klonopin, Ativan) withdrawal begins in 1-4 days and peaks around two weeks, although protracted withdrawal, marked by rebound anxiety, can last months or years.

Withdrawal from alcohol can begin within hours of the last drink and peak over the course of 24-48 hours. Alcohol withdrawal poses a risk of seizures 6 hours to 48 hours after withdrawal begins, and the risk peaks at 24 hours. Alcohol withdrawal delirium, or delirium tremens (DTs), marked by confusion and disorientation, occurs in approximately 5 percent of those experiencing alcohol withdrawal, can start 2-3 days after the end of a long binge, and lasts 2-3 days or more. It requires medical supervision and treatment.

Withdrawal symptoms do not occur with all substances; for example, stopping hallucinogens or marijuana does not typically lead to withdrawal symptoms. Further, the intensity of withdrawal depends on the amount of drug usually taken and the duration of its effects.

The course of withdrawal is different for different substances. Studies show that the opioid heroin, a central nervous system depressant, has a half-life in the body of 2 to 6 minutes, and withdrawal symptoms start usually 6 to 24 hours after the last dose. They reach a peak at 24 to 48 hours, and they resolve after four to 10 days.

Abrupt cessation of stimulants like cocaine produces a different pattern of withdrawal; it occurs in three distinct phases—crash, withdrawal, and extinction—and is not considered medically dangerous. The half-life of the drug in the body is 90 minutes. The crash phase, which starts as the drug high wears off, can last for several days—marked by fatigue, flat mood, increased sleep, increased appetite, restlessness, but reduced cravings. The major danger is severe depressive symptoms. Withdrawal symptoms set in, peak, and then decline over the next week to 10 weeks, and can include anxiety, severe drug cravings, lethargy but erratic sleep, and emotional instability. The extinction phase, of episodic cravings, dysphoria, and poor concentration, can extend to 28 weeks.

The abrupt stoppage of a substance to which the brain has become accustomed exposes all the adaptations the brain has made to its presence. That kicks off a rebound of activity in many neurotransmitters and their receptors in many brain systems. The resulting symptoms constitute withdrawal, and the effects a person experiences are generally the opposite of those induced by the drug abused.

For example, alcohol is a known depressant of the central nervous system. Over time, various neurochemical systems of the brain adjust their output and sensitivity to compensate for its presence, typically producing increased amounts of stimulating neurochemicals like noradrenaline. When the alcohol is then abruptly stopped after long, heavy use, the brain, unable to immediately readjust its chemistry, is suddenly subject to overstimulation. Among the consequences are tremors (“the shakes”), spikes in heart rate and blood pressure, irritability, nausea, and anxiety. Hallucinations—especially seeing small moving objects—and seizure can occur.

“Cold turkey” is the colloquial term applied to abruptly and completely stopping use of a substance on which a person has become dependent, precipitating withdrawal symptoms. The alternative to cold turkey is gradually tapering use of a substance or undergoing medication-assisted treatment of addiction, in which the effects of the addictive substance are wholly or partially blocked by much safer medication. Cold turkey precipitates withdrawal symptoms, and there’s evidence that it can shorten the withdrawal phase and jump-start recovery from harmful health effects of the substance used.

Abruptly stopping benzodiazepines or heavy alcohol use can be dangerous, even life-threatening, and medical supervision is widely recommended. Stopping moderate alcohol use or opiates, and immediately precipitating withdrawal, is extremely unpleasant but not generally physically dangerous.

Abruptly stopping use of opiates such as heroin is generally considered extremely unpleasant but not life-threatening. Major symptoms include intense flu-like distress, anxiety, insomnia, muscle aches and pains, lacrimation, nausea, vomiting, and diarrhea. However, vomiting and diarrhea pose the risk of severe dehydration and heart failure. Medical management is generally advised.

There is mixed evidence suggesting that abruptly quitting smoking—especially with supportive therapy—is more effective than gradual cessation. Nicotine withdrawal peaks at 3-5 days after stopping, Cravings, headache depression, irritability, mental fog, and increased appetite are common symptoms—unpleasant but not usually dangerous. Cold turkey is generally considered a safe way of quitting smoking.

Withdrawal from alcohol and benzodiazepines creates physical dangers as well as psychological symptoms. The primary risk stems from rebound excitation of the nervous system, leading to rapid shifts in blood pressure, heart rate, and breathing, as well as the possibility of seizures. Under medical supervision, drugs are typically administered to dampen the excitability of the nervous system and to ease discomfort. In addition, alcohol abuse serious enough to cause withdrawal symptoms often is associated with severe nutritional deficiencies, warranting infusions of several vitamins and minerals.

Specific pharmaceutical agents, notably buprenorphine, are available to counter the symptoms of withdrawal from opioids, such as heroin, oxycodone, and fentanyl. Many experts believe that medication assisted treatment (MAT) for opioid addiction is vastly underutilized, largely because there is lingering belief that complete abstinence from any substance is the only way to overcome addiction.

With other substances, withdrawal symptoms are often exceedingly unpleasant—shakiness, irritability, intense anxiety or depression, flu-like symptoms. They are treated with common medications that provide symptomatic relief.