About problematic substance use

Substances, such as drugs and alcohol, can cause both psychological and or physical dependence, which can lead to problematic substance use and substance use disorder.

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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 opioid use

Opioids have the potential for problematic use because they can produce a feeling of euphoria or a "high".

Problematic opioid use is using opioids that are not prescribed to you or not following the instructions from your doctor and pharmacist. It also includes using illegal opioids.

Substance use disorder

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

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 stops or reduces taking drugs or alcohol after using regularly for a long time or after using high doses. If someone suddenly stops taking drugs, such as opioids, they can experience withdrawal.

Severe alcohol withdrawal is very dangerous and can even cause death.


  • 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 was used

Getting Help

Getting help can mean different things for different people and it can take many different forms. The chronic nature of the disease means that relapsing and re-using drugs 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.

For more information

  • Help is available whether you need it for yourself, a friend or a family member. You can also contact your health care provider for help with substance use disorder.
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