Substance Use Disorder vs. Physical Dependency: What Are the Differences?

Substance use disorder (SUD) and physical dependency on substances are not the same. "Substance use disorder" is the medical term for addiction. It can occur without dependency. SUD applies in situations in which a person compulsively uses a substance despite harmful consequences to their health, finances, and/or relationships.

SUD creates changes in the brain that make it particularly difficult to stop using the drug. Depending on the substance and the severity of addiction, a person can experience mild to severe withdrawal symptoms and cravings when attempting to stop, making it all the more difficult to refrain from continuing using.

Physical dependency is when a person’s body adapts to the presence of a certain drug in their system. Without the substance, a person may experience physical symptoms. When physical dependency emerges, addiction often closely follows.  

This article will share more about the differences between substance use disorder and physical dependency. Be sure to speak with your primary care physician if you have concerns about any medications you are taking and the potential for dependency and addiction. 

Symptoms

Physical dependency on a drug can manifest as tolerance to the substance or as withdrawal. These are considered symptoms of SUD, however they don’t need to be present for the diagnosis of SUD to be made. Tolerance is when you need larger amounts of the drug to get the same effect. Withdrawal symptoms are physical symptoms that occur when the substance is decreased or stopped as the body readjusts to not having the substance.

Symptoms of substance use disorder include:

• Drug-seeking, securing, and using behaviors that develop into a priority 
• Continuing using drugs despite harmful consequences
• Uncontrollable use (i.e., having trouble reducing or stopping use)
• Neglecting social and work obligations because of drug use
• Tolerance for the substance as your body adapts to the drug, leading to cravings for larger or more frequent doses
• Withdrawal symptoms that differ based on drug type
• Brain changes in areas that are critical for judgment, decision-making, learning, memory, and behavior control
  

Causes of SUD and Dependency

About half the risk of developing an addiction or substance use disorder is caused by genetics. The reason is that genes affect how someone experiences reward when initially using a substance, as well as the way the body processes alcohol or other drugs.

Other contributing factors include:

• Environmental stressors, such as not feeling safe at home or undergoing trauma
• Social pressures and norms, such as peer pressure
• Individual personality characteristics
• Psychiatric problems

Dependency is caused by the ongoing presence of a drug in your system. For example, a person may become physically dependent on antidepressant medications prescribed to treat depression, even experiencing withdrawal symptoms when tapering down or stopping using. This is because your body has adapted to having the drug. It is not the same as being addicted to an antidepressant. 

Diagnosing SUD vs. Dependency

Diagnosis of substance use disorder usually occurs after discussing your medical history and symptoms with your primary care provider, a psychiatrist, or a qualified mental health professional. This clinician will take into consideration your medical history (including whether SUD runs in the family), the substance being used, the frequency of use, and the length of time since last used to make an accurate call on whether or not use has become problematic. You will likely be asked a series of questions about your usage and any effects it has had on your relationships and responsibilities. 

A medical professional will take all of the following into consideration as they evaluate someone for a substance use disorder:

• Weight loss
• Constant fatigue
• Changes in hygiene
• Lab test abnormalities
• Unexpected abnormalities in heart rate or blood pressure
• Depression, anxiety, or sleep problems

Treatment

Treatment for substance use disorder and physical dependence differ, which is why knowing the difference between the two is so important.

Treating Substance Use Disorder

Substance use disorder is treatable. Depending on the severity of use, treatment may involve inpatient or outpatient support including a medical detoxification program, various forms of therapy like cognitive behavioral therapy (CBT) or family-based interventions, medication-assisted treatment for the SUD (if applicable), and peer support or recovery service groups. 

Treatment for SUD may also involve taking medication to treat coexisting conditions like depression or anxiety that may be contributing to the use disorder.

According to the National Institute on Drug Abuse (NIDA), the purpose of treatment for SUD is to get you to:

• Stop using drugs
• Not return to use
• Be productive in the family, at work, and in society 

The right treatment is the treatment that you can access, will commit to, and that will help you achieve and maintain abstinence. Drug and/or alcohol abstinence while in treatment and during recovery from a substance use disorder is associated with a more positive long-term prognosis. 

Treating Physical Dependency

A person being treated for physical dependency in the absence of any substance use disorder will be closely monitored by the prescribing healthcare provider as they taper or decrease the dosage slowly over time rather than all at once. Medications may be needed to reduce the impact of any withdrawal symptoms.

Since there are many substances on which one can develop a physiological dependency, each substance in question requires an individualized approach.

Not all physical dependency should be treated as something to be fixed, though. Bear in mind a person can be dependent on certain medications for chronic conditions that will be required for the rest of their life. For example, a person with type 1 diabetes (sometimes called insulin-dependent diabetes) will not be treated for this dependency as it is necessary to their survival. 

Prevention

Preventing problematic substance use is possible. Different prevention methods can be used depending on whether the substance is prescribed or can be found over-the-counter or elsewhere.

Prescription Medications

Some medications have a higher risk for abuse and the development of substance use disorders. They include opioid pain relievers, stimulants used to treat ADHD (attention deficit hyperactivity disorder), and benzodiazepines to treat anxiety or sleep disorders.

Preventing substance use disorders in these cases begins with screening the patient for prior or current substance use problems and assessing their family history of substance misuse or addiction before prescribing a psychoactive medication. It also includes closely monitoring patients who are prescribed such drugs. 

Prescribing healthcare providers also need to educate patients about the potential risks so that they will follow their provider's instructions, safeguard their medications, and dispose of them appropriately, according to NIDA.

Nonprescription Medications

Dependencies and use disorders can also develop when taking nonprescription substances, including alcohol and cannabis as well as hallucinogens (drugs that cause hallucinations). While there is no single recipe for preventing substance use disorders, the following are all strategies that reduce risk:

• Understand what substance use disorder is and how it develops.
• Develop healthy friendships that don’t involve pressures to use drugs.
• Seek professional help for mental health concerns (avoid self-medicating).
• Know your personal risk factors including whether or not SUD affects family members.
• Develop healthy stress management strategies to help you live a balanced life (avoid escaping feelings with drug use)
• Talk to someone if you think you or someone else is developing a problem with drug use

Summary

Substance use disorder and physical dependency are related, but not the same. "Substance use disorder" is the medical term for addiction and physical dependency describes the phenomenon of your body becoming physiologically dependent on a substance. The line between the two can sometimes be blurred, though, especially when discussing potentially habit-forming prescriptions like opioids.

When taking prescriptions or using any substances, it’s best to keep an open and ongoing dialogue with your medical care team and monitor for signs of problematic use. You can also always talk to your local pharmacist about any concerns you may have.

A Word From Verywell

There is no shame in experiencing a substance use disorder or physical dependency. Many factors can contribute to the development of either of these. Thankfully, there is help and many treatment options available. If you are concerned that you may be experiencing a substance use disorder of any kind, talk to your healthcare provider. It can help to lean on a supportive community of loved ones as you go through the recovery process.