What Is a Substance Use Disorder

This page reflects our understanding of mental health topics as of 2026. If you are reading this at a later date, some details may no longer be current, so please verify anything important against up to date sources. If you notice anything that needs updating, we would welcome you letting us know.

Stopping alcohol or certain other substances suddenly after heavy use can be dangerous. Speak with a doctor before cutting back. If someone shows signs of overdose, such as slow or no breathing, unresponsiveness, or blue lips, call 911 immediately. For thoughts of suicide, call or text 9-8-8.

A substance use disorder is a pattern of using alcohol or drugs that continues despite causing problems and that feels increasingly hard to control. It can involve alcohol, cannabis, opioids, stimulants, sedatives, or other substances. Substance use disorders range from mild to severe and are considered health conditions, not moral failings. They develop from a combination of biology, environment, and emotional factors, and they are treatable. Many people recover, often with support.

What a Substance Use Disorder Looks Like

Clinicians look for a pattern of use that leads to significant problems over time. Common signs include:

Using more, or for longer, than intended. The page on drinking more than you planned explores this.
Wanting or trying to cut down without success.
Spending a lot of time getting, using, or recovering from the substance.
Strong cravings or urges.
Falling behind at work, school, or home.
Continuing despite relationship problems caused or worsened by use.
Giving up activities that once mattered.
Using in risky situations, such as driving.
Needing more to get the same effect (tolerance), or experiencing withdrawal when stopping.

At home, this may look like hiding use or conflict with family. At work, it may show up as missed days or declining performance. Some people rely on alcohol to unwind or use cannabis to relax every night before realizing the pattern has grown.

Why It Happens

Substance use disorders develop through several interacting factors. Genetics influence risk. Substances affect the brain's reward system, and repeated use can change how that system works, strengthening cravings and habits. Many people use substances to cope with stress, anxiety, depression, trauma, pain, or loneliness, and relief makes use more likely to continue. Social environment, early exposure, and easy access also matter. ADHD, PTSD, and other conditions are associated with higher risk.

What It Is Not

Not a lack of willpower. Substance use disorders involve real changes in brain function and are shaped by many factors outside personal control.
Not all substance use. Many people use alcohol or cannabis without developing a disorder. The concern is loss of control and harm.
Not the same as physical dependence alone. Some people on prescribed medications develop tolerance or withdrawal without having a disorder.
Not separate from mental health. Substance use disorders often co-occur with anxiety, depression, trauma, and ADHD, and treating both together tends to work best.

How It Is Assessed and Treated

A doctor, psychologist, or addiction specialist can assess substance use by exploring patterns, consequences, and related mental and physical health. Treatment options include therapy approaches such as cognitive behavioural therapy and motivational interviewing, medical management of withdrawal, medications prescribed by a physician for some substance use disorders, peer support groups, and harm reduction strategies. Goals can vary, from reducing use to stopping entirely. Recovery is often gradual and may include setbacks, which are part of the process rather than failure.

Getting Support at Pacific Maple Psych Centre

If substance use is causing problems in your life, therapy can help you understand what drives it, build coping skills, and work toward goals that feel right for you. We encourage involving your doctor as well, especially if you are considering stopping.

Pacific Maple Psych Centre offers individual therapy for substance use concerns and related anxiety, depression and trauma, in Vancouver and virtually across British Columbia.

Book a Session

Common Questions About Substance Use Disorder

What counts as a substance use disorder?

It is a pattern of alcohol or drug use that causes significant problems and feels hard to control, such as using more than intended, cravings, and continuing despite harm.

What is the difference between substance use and a substance use disorder?

Many people use substances without problems. A disorder involves loss of control, cravings, and negative consequences that continue over time.

Is addiction the same as a substance use disorder?

The terms are often used interchangeably. Clinicians use substance use disorder and rate it as mild, moderate, or severe. Addiction usually refers to more severe patterns.

Which substances need medical support when stopping?

Alcohol, benzodiazepines, and some other sedatives can cause serious or even life-threatening withdrawal after heavy, regular use. Opioid withdrawal is also very difficult. Speak with a doctor before stopping.

Can anxiety or trauma lead to substance use problems?

Yes. Many people use substances to cope with anxiety, depression, or trauma. The relief can make use more likely to continue and develop into a disorder.

Is a substance use disorder a choice?

No. While early use may be a choice, substance use disorders involve changes in the brain and are influenced by genetics, environment, and mental health.

What is harm reduction?

Harm reduction focuses on reducing the negative consequences of substance use, such as through safer use practices, without requiring abstinence as a first step.

Do I have to stop completely to recover?

Not always. Goals vary. Some people aim for abstinence, while others work toward reduced or safer use. A clinician can help you decide what is safest.

How can I help a family member with a substance use disorder?

Express concern without judgment, learn about the condition, set boundaries, and encourage professional support. Family support groups can also help you.

What treatments are available for substance use disorders?

Options include therapy such as CBT and motivational interviewing, medical withdrawal management, medications for certain substances, peer support, and harm reduction services.