What is substance use disorder?

Substance use disorder is the medical term used to describe a pattern of using a substance (drug) that causes significant problems or distress. This may be missing work or school, using the substance in dangerous situations, such as driving a car. It may lead to substance-related legal problems, or continued substance use that interferes with friendships, family relationships, or both. Substance use disorder, as a recognized medical brain disorder, refers to the use of illegal substances, such as marijuana, heroin, cocaine, or methamphetamine. Or the misuse of legal substances, such as alcohol, nicotine, or prescription medicines. Alcohol is the most common legal drug associated with substance use disorder.

Substance (drug) dependence

Substance dependence is the medical term used to describe use of drugs or alcohol that continues even when significant problems related to their use have developed. Signs of dependence include:

• Tolerance to or need for increased amounts of the drug to get an effect

• Withdrawal symptoms that happen if you decrease or stop using the drug that you find difficult to cut down or quit

• Spending a lot of time to get, use, and recover from the effects of using drugs

• Withdrawal from social and recreational activities

• Continued use of the drug even though you are aware of the physical, psychological, and family or social problems that are caused by your ongoing drug use

What substances are associated with substance use disorder?

Substances frequently include:

• Alcohol

• Marijuana

• Prescription medicines, such as pain pills, stimulants, or anxiety pills

• Methamphetamine

• Cocaine

• Opiates

• Hallucinogens

• Inhalants

What causes substance use disorder?

Cultural and societal factors determine what are acceptable or allowable forms of drug or alcohol use. Public laws determine what kind of drug use is legal or illegal. The question of what type of substance use can be considered normal or acceptable remains controversial. Substance use disorder is caused by multiple factors, including genetic vulnerability, environmental stressors, social pressures, individual personality characteristics, and psychiatric problems. But which of these factors has the biggest influence in any one person cannot be determined in all cases.

What are the symptoms of substance use disorder?

The following are the most common behaviors that mean a person is using or misusing drugs or alcohol. But each person may have slightly different symptoms. Symptoms may include:

• Using or drinking larger amounts or over longer periods of time than planned.

• Continually wanting or unsuccessfully trying to cut down or control use of drugs or alcohol.

• Spending a lot of time getting, using, or recovering from use of drugs or alcohol.

• Craving, or a strong desire to use drugs or alcohol.

• Ongoing drug or alcohol use that interferes with work, school, or home duties.

• Using drugs or alcohol even with continued relationship problems caused by use.

• Giving up or reducing activities because of drug or alcohol use

• Taking risks, such as sexual risks or driving under the influence.

• Continually using drugs or alcohol even though it is causing or adding to physical or psychological problems.

• Developing tolerance or the need to use more drugs or alcohol to get the same effect. Or using the same amount of drugs or alcohol, but without the same effect.

• Having withdrawal symptoms if not using drugs or alcohol. Or using alcohol or another drug to avoid such symptoms.

The symptoms of substance use disorder may resemble other medical problems or psychiatric conditions. Always consult your doctor for a diagnosis.

How is substance use disorder diagnosed?

A family doctor, psychiatrist, or qualified mental health professional usually diagnoses substance use disorder. Clinical findings often depend on the substance, the frequency of use, and the length of time since last used, and may include:

• Weight loss

• Constant fatigue

• Red eyes

• Little concern for hygiene

• Lab abnormalities

• Unexpected abnormalities in heart rate or blood pressure

• Depression, anxiety, or sleep problems

Treatment for substance use disorder

Specific treatment for substance use disorder will be determined by your doctor based on:

• Your age, overall health, and health history

• Extent of the symptoms

• Extent of the dependence 

• Type of substance you are using

• Your tolerance for specific medicines, procedures, or therapies

• Expectations for the course of the condition

• Your opinion or preference

A variety of treatment (or recovery) programs for substance use disorder are available on an inpatient or outpatient basis. Programs considered are usually based on the type of substance. Detoxification (if needed, based on the substance) and long-term follow-up management or recovery-oriented systems of care are important features of successful treatment. Long-term follow-up management usually includes formalized group meetings and psychosocial support systems, as well as continued medical supervision. Individual and family psychotherapy are often recommended to address the issues that may have contributed to and resulted from the development of a substance use disorder.