Understanding substance use and addiction

People from all walks of life use substances. The reasons are varied, including to socialize, celebrate, cope with stress, manage physical and emotional pain or get through challenging circumstances. For some, substance use can become harmful when it starts to have a negative effect on their health, relationships, work or day-to-day life.

What is the difference between substance use and addiction?

Substance use refers to the use of substances such as alcohol, cannabis or other drugs. While not all substance use leads to harm, it can carry risks, and those risks can vary depending on the substance, how much is used, how often it is used and a person’s circumstances.

When substance use begins to have a negative effect on a person’s life and relationships or becomes difficult to control, they may be experiencing a substance use problem or addiction. The word addiction is often used to describe a behaviour that cannot be controlled.[1] But it’s much more than that.

An easy way to understand addiction is through the four Cs:[2]

• Craving: Strong urges to use.
• Control: Difficulty controlling how much or how often you use.
• Compulsion: Feeling driven to use.
• Consequences:Continuing to use despite negative impacts.

What are the signs that substance use may be becoming a problem?

Substance use problems can develop gradually. What may begin as occasional use can become more frequent or harder to manage over time. Sometimes, the effects are obvious. At other times, they can be difficult to recognize, especially when someone is trying to cope with stress or other challenges.

There is no single sign that indicates someone is experiencing a substance use problem. However, changes in behaviour, mood, health or daily routines may be worth paying attention to.

Here are some signs to look out for:

• Changes in mood or mental health. A person may experience increased anxiety, irritability, sadness or depression, or have difficulty managing their emotions.
• Impacts on relationships. Substance use may contribute to conflict with friends, family members or partners, or cause someone to withdraw from people they care about.
• Changes in everyday responsibilities. They may regularly miss work, school or appointments, or find it harder to keep up with daily tasks.
• Physical health concerns. These may include injuries while under the influence, blackouts, feeling unwell after using the substance or other health complications.
• Financial difficulties. Money spent on substances may make it harder to pay the bills and afford essentials, such as food.
• Continuing to use despite negative consequences. A personmay recognize that their substance use is harming them but continue using, even when they want to stop.

The connection between mental health and substance use

Mental health and substance use are closely connected. [3] Among those experiencing a substance use disorder, almost 50% also have a mood or anxiety disorder.[i] While substance use may provide temporary relief for some people, it can also worsen mental health symptoms over time. For example, alcohol and other substances can affect sleep, mood and emotional regulation, potentially making existing challenges more difficult to manage. It can also work in the other direction where substance use problems can contribute to anxiety, depression, isolation and other mental health concerns.

How to support someone who may be struggling

If you’re concerned about a friend, family member or colleague, starting a conversation can feel intimidating. You may worry about saying the wrong thing or making the person uncomfortable. It’s important to remember that you don’t need to have all the answers. Showing care and compassion and creating space for an honest conversation can make a difference.

Here are a few ways to offer support:

• Lead with compassion, not judgment. Avoid labels or assumptions about why someone is using substances. Let them know you don’t blame or judge them. You care about their well-being and are there to support them.
• Choose a time to talk. When possible, find a private, calm moment when the person is not feeling the effects of alcohol or drugs. Share what you’ve noticed without making assumptions. For example, you might say, “I’ve noticed you’ve seemed overwhelmed lately, and I’m worried about you. How have you been doing?”
• Listen without trying to fix everything. Give the person an opportunity to share what they’re experiencing. You may not fully understand their situation, but listening without judgment can help them feel less alone.
• Offer practical support. If they’re open to it, help them explore healthcare services, counselling, peer support or local substance use programs. You could offer to look up resources together or accompany them to an appointment.
• Respect boundaries. You can care about someone and offer support without being responsible for their choices or recovery. If the person isn’t ready to talk or seek help, let them know you’re available when they’re ready, while also taking care of your own well-being.

Taking the first step toward support

Talking about substance use and addiction can feel difficult. Stigma, shame and misconceptions can make it harder for people to recognize when they need help or feel comfortable reaching out for support.

Understanding how substance use problems can affect a person’s life can help us challenge stigma, recognize when something may be wrong and connect the person to support.

If you or someone you know is dealing with a substance use problem or addiction, talking with a healthcare provider, counsellor or trusted person can be a starting point. You can also explore local substance use health services and peer support options.

National Addictions Awareness Week is November 15-21. Everyone deserves the opportunity to get support without shame or judgment. To learn more, visit the Canadian Centre on Substance Use and Addiction at ccsa.ca.

[1] https://www.camh.ca/en/health-info/mental-illness-and-addiction-index/addiction

[2] https://www.camh.ca/en/health-info/mental-illness-and-addiction-index/addiction

[i] Halladay, Jillian, Chris Ji, Katholiki Georgiades, Tim Slade, Cath Chapman, Matthew Sunderland, and James Mackillop, “Co-occurring mood, anxiety, and substance use disorders in Canada 2022: prevalence, patterns, correlates, and changes over time,” Psychiatry Research vol. 365 (2026).