1. Understanding Substance Use Problems and Addiction

Why do people use alcohol and other drugs?

Reasons for substance use


Substance use is very common.

Alcohol is the most commonly used substance, with 76 per cent of Canadians aged 15 years or over reporting that they use it (Health Canada, 2013).

pie chart showing 76%

In 2015, 13 per cent of people in Canada reported using at least one of six illegal substances, an increase from 11 per cent in 2013. The increases were mainly in the use of cannabis, hallucinogens and ecstasy (Health Canada, 2017). 1

People often begin using substances because it is pleasurable or reinforcing in some way. Substances can be internally reinforcing (e.g., using helps the person avoid dealing with their personal issues) or externally reinforcing (e.g., using helps a person fit in). Using substances may help a person to:

    avoid dealing with problems
    feel better
    cope with stress
    increase their sense of confidence
    do something they would not otherwise do
    fit in with peers
    increase their status within a group
    dull emotional pain
    deal with physical pain.

A substance’s ability to provide reinforcement may change over time. For example, drinking alcohol may help a person sleep initially, but these effects may wear off.

1. This study was completed before the legalization of cannabis in 2018; as such, cannabis is defined as an illegal substance.