Drug dependence, or physical dependence, refers to when a person requires one or more drugs in order to function. Abruptly stopping the substance may cause physical symptoms of withdrawal.

Although this can refer to dependence on medications that control health conditions, it can also be a symptom of addiction, which is different from physical dependence.

The term physical dependence refers to being physically dependent on a substance but not meeting the criteria for addiction. For example, a person receiving pain medication during cancer treatment may be dependent on the medication, but that does not mean that they have an addiction to it.

The American Psychiatric Association (APA) used to distinguish between physical dependence and substance abuse. However, with the release of the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5), the APA consolidated both terms with substance use disorder (SUD).

However, the SUD community is trying to make a clear distinction between SUD and physical dependence to avoid confusion, mislabeling, and stigma.

This article will discuss what physical dependence is, as well as its causes, symptoms, and treatments. It will also cover when a person should seek help.

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Physical dependence refers to the reliance on a substance to help a person get through the day. People may also refer to it as withdrawal syndrome, dependence syndrome, or abstinence syndrome, and it occurs when symptoms of withdrawal appear after a person stops taking a substance abruptly.

However, physical dependence does not equal addiction. People can experience physical dependence on prescription opioids, antidepressants, anti-epileptics, or benzodiazepines without having an addiction to them.


However, physical dependence — alongside other symptoms — may meet the criteria for SUD, according to DSM-5. By using this definition, the APA hope to prevent stigmatization associated with terms such as dependence, abuse, and addiction.

SUD is a complex condition wherein a person uncontrollably uses a substance despite this having harmful consequences.

Repeated use of these substances may result in changes in how the brain functions. This may result in withdrawal symptoms. Additionally, people may build up a tolerance to the substance, meaning that they require more of the drug to feel its effects.

SUD can result in behavioral, physical, and social changes, such as mood changes, deterioration of appearance, and strained relationships with friends and family.

Addiction is interchangeable with the term SUD, and physical dependence falls under the SUD umbrella. Although some people may use the terms interchangeably, physical dependence does differ from addiction.

Dependence refers to the physical symptoms of withdrawal and tolerance, while SUD refers to long-term behavioral, social, and physical changes.

It is possible for a person to experience dependence without SUD. This can often occur when the person requires long-term pain medications for chronic pain. These individuals may become dependent on pain medications to function, but they may not have an addiction to pain medication.

Physical dependence usually develops as a result of repeatedly consuming a given substance over a period of time. Although researchers do not fully understand the precise mechanisms, it is possible that the substances cause changes to occur in the brain and central nervous system.

Repeated exposure to a substance alters a person’s brain structure and brain chemicals to accommodate a drug. This results in alterations in homeostasis. This is the state that the body maintains for optimal functioning.

Abruptly stopping this substance disrupts homeostasis, and the body must adapt to not having the drug in the body. This may result in withdrawal symptoms.

According to the DSM-5, the characteristic symptom of physical dependence is withdrawal.

Although not all people will experience the same symptoms of withdrawal, some of the more common symptoms may include:

  • aching muscles
  • muscle spasms
  • anxiety or agitation
  • increased heart rate
  • difficulty concentrating
  • detachment from reality
  • nausea and vomiting
  • diarrhea
  • depression
  • hallucinations or delusions

People may be able to divide the symptoms of physical dependence into either acute withdrawal syndrome or post-acute withdrawal syndrome (PAWS).

Acute withdrawal syndrome usually lasts for a relatively short period of time, while PAWS is a low level continuation of some symptoms that can last for years or even indefinitely.

Drugs typically associated with the development of strong physical dependence may include the following.


Opioids, such as codeine, are drugs that a doctor may prescribe to treat pain. Although these are effective for pain relief, they have a high risk of causing physical dependence if a person uses them for longer than prescribed.


Antidepressants are a class of drug that may help reduce anxiety, low mood, and suicidal thoughts.

Although doctors do not generally consider antidepressants to be addictive, they note that some individuals may develop physical dependence on them. If the person abruptly stops the antidepressant they are taking, it could cause withdrawal symptoms.

Learn more about safely stopping antidepressants here.


Benzodiazepines are a group of drugs called nervous system depressants. People may take these to treat anxiety or sleeping issues.

Like opioids, experts tend to consider them relatively safe when a person takes them as needed, sparingly, and for short periods of time.

When taking them chronically or over long periods of time, however, physical dependence may develop. This dependence may lead to a difficult withdrawal if the person chooses to stop taking the drugs.

Learn more about benzodiazepine withdrawal here.


Barbiturates are a group of drugs that have calming effects on the body.

Given that barbiturates work in the body in a very similar way to benzodiazepines, the risk of physical dependence is still present. Some research suggests that barbiturate use has a high potential for physical dependence.

Illicit drugs

Although it is much rarer, some people may experience physical dependence, without meeting the criteria for addiction, to certain illicit drugs. These include cocaine, methamphetamine, and ketamine.

Physical dependence does not necessarily require treatment. For example, if a person needs to take opioids long term, doctors will not recommend treatment for opioid dependence.

In fact, most people can manage their physical dependence in an outpatient setting with a simple, slow taper of that substance rather than stopping it abruptly.

When someone has SUD, however, they can receive treatment. Depending on the substance, the individual may require detoxification as the first step in their treatment plan.

Receiving treatment for SUD may include taking medications to curb substance cravings and decrease withdrawal symptoms. However, it can also include other aspects, such as undergoing psychosocial therapy.

In extreme cases of withdrawal, intoxication, or overdose, a person may also require emergency care before they receive treatment for SUD.

A person should contact a doctor if they believe that they have a physical dependence on their medication or think that they might be developing one. People with SUD should also contact a doctor. They have the same right to treatment and care as a person with any other health condition.

Doctors will work with people to find a treatment that works for them that reduces their chances of relapsing, in the case of SUD.

Doctors may also refer people to rehabilitation centers. These centers, which are often in-patient facilities, specialize in treating SUD. However, they may not help with physical dependence.

Physical dependence is a medical condition that is separate from addiction. When abruptly stopping a substance, a person may experience adverse symptoms of withdrawal, such as confusion, hallucinations, and seizures.

People do not necessarily need to seek treatment for physical dependence. In most cases, people can manage their physical dependence by slowing tapering the drug instead of stopping it abruptly.