About problematic substance use

Substances, such as drugs and alcohol, can cause both psychological and physical dependence, which can lead to problematic substance use and substance use disorder, also known as addiction. This includes problematic use of prescription drugs.

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When someone who uses substances, such as drugs or alcohol, becomes accustomed to a particular dose and needs higher amounts in order to obtain the same effects, he or she is likely to have developed a tolerance to the drug or substance. Tolerance develops over time and will change depending on many factors, such as:

  • age, sex and weight;
  • any medical or mental health conditions;
  • the amount of the drug consumed; and
  • the combined use with other drugs like:
    • alcohol
    • prescription drugs
    • other illegal drugs
    • over-the-counter medication

Most importantly, people who don't use drugs, or have taken a break from using the drug, may experience lower drug tolerance. This can put them at greater risk of overdose because they might use more drug than their body can now handle.

Problematic substance use

Problematic substance use happens when someone uses drugs or alcohol in a harmful way that has negative effects on their health and life.

Drugs and alcohol have the potential for problematic use because they produce feelings that may feel good to someone, such as a feeling of calm or increased energy or euphoria, or a "high". These feelings can lead to a person to continue to seeking out the drugs or alcohol.

Problematic prescription drug use

Intentionally taking medication that hasn't been prescribed to you or taking more than is prescribed to get high or change your mood, is problematic prescription drug use.

The most common types of prescription drugs that can lead to problematic use include:

  • opioids, which can be prescribed to treat certain kinds of pain
  • benzodiazepines, which can be prescribed to treat anxiety and sleep disorders
  • stimulants, which can be prescribed to treat attention deficit-hyperactivity disorder (ADHD)

Problematic use of these medications can cause serious health effects, including substance use disorder (addiction), overdose and even death.

These risks increase when medications are:

  • taken at higher doses than prescribed
  • taken in a different way or for different reasons than they were prescribed
  • used with alcohol or other prescription, over-the-counter or illegal drugs

Help prevent problematic prescription drug use

To help prevent problematic prescription drug use, you should:

  • keep track of your prescription drugs by counting the pills in each package
  • keep medication in a safe and secure place, such as a locked box or cabinet
  • return any unused or expired medications to your pharmacy or to a take-back program
  • keep track of your refills at the pharmacy and make sure there are none that you didn't fill yourself
  • avoid sharing your medication with family or friends, even if they have been prescribed the same drug before

Substance use disorder

When someone regularly uses drugs or alcohol despite continued negative consequences, they may have substance use disorder, otherwise known as addiction.

It is a medical condition that often requires treatment from health care providers. Substance use disorders can involve both psychological and physical dependence.

If someone you know has one or more of the following behaviors, they may be experiencing a substance use disorder:

  • constant cravings for the drug or alcohol;
  • compulsive drug or alcohol seeking; and
  • continuous use despite the harms that drugs or alcohol is causing, such as:
    • negative health effects;
    • missing school or work;
    • lower grades or marks at school;
    • isolation from friends and family members; and
    • extreme changes in behaviours and mood.

Negative effects of substance use

Overtime, the harms associated with problematic substance use may come to outweigh any perceived positive effects. Problematic drug or alcohol use can impact many parts of a person's life:

  • Mental Health - problematic substance use can affect mental health in many ways. Most often it can trigger mood, anxiety or depression disorders, but it can also increase the risk of developing a serious mental health illness, such as psychosis or schizophrenia.
  • School - using substances can affect someone's ability to study, to concentrate in class, and to keep up with assignments.
  • Work - if someone cannot focus because of their problematic substance use, they might lose their job. Worse, they could endanger or hurt themselves or others at work.
  • Relationships - problematic substance use can create an environment of secrecy, conflict, emotional chaos and fear, which can seriously impact surrounding relationships.
  • Money - using substances can be expensive. People might struggle to pay bills or buy the things they need.
  • Mood - people may feel good while they use substances, but they feel worse when the effects wear off.
  • Sex - using substances might make people forget to practice safe sex. The result of unprotected sex could be a sexually transmitted diseases or an unwanted pregnancy.
  • Legal problems - illegal sale or possession of drugs can dramatically affect a young person's future. If charged and convicted, they will have a criminal record that may present problems in the future with potential employers or when travelling out of the country.
  • Health and safety
    • Heavy use of some drugs and substances don't just affect your brain, it can also damage your physical health and your organs, such as your liver, kidneys and lungs.
    • As well, if you share drug paraphernalia, such as needles or pipes, you might be at a greater risk of blood-borne infections and other infection diseases like hepatitis C or HIV.
    • Driving impaired by a drug or substance puts a person at higher risk of having an accident and getting hurt or hurting someone else.


Withdrawal symptoms occur when a person reduces or stops taking drugs or alcohol after using regularly for a long time or after using high doses. If someone suddenly stops taking drugs or alcohol, such as opioids, they can experience withdrawal and sometimes even death.

Symptoms of withdrawal include:

  • Nervousness / Irritability / Agitation
  • Chills / Sweating
  • Diarrhea / Nausea / Stomach pain
  • Insomnia
  • Body aches / Widespread or Increased pain

Severity and length of withdrawal depends on:

  • which drug was used
  • how much was taken
  • how long the drug or alcohol was used

Getting Help

Getting help can mean different things for different people and it can take many different forms. The chronic nature of substance use disorder or addiction means that relapsing and re-using drugs or alcohol at some point is not only possible, but likely. It's important for people to know that successful treatment is not determined by immediate, long-term abstinence. Treatment is successful when the person understands their substance use disorder and seeks help if a relapse takes place. Returning to treatment and healthier behaviours should be considered a success.

Recovery from substance use disorders is possible. People can, and do, overcome problematic substance use. A person in recovery is going through an individual process to improve their physical, psychological and social health, which can take time. What this recovery looks like could include complete abstinence (i.e. avoiding drugs or alcohol completely) or medication assisted treatment, such as prescribing methadone or buprenorphine to treat opioid use disorder.

There are also many health and social services available across Canada including non-medical therapies, such as counselling, or support from people with lived and living experience.

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