Public Health works at the population level to prevent harms associated with substance use. We work to address the social determinants of health, like housing, income, and access to services, that can lead to problems with substance use and poorer health. Learn more about this work.
The substance use spectrum
People use substances, such as controlled and illegal drugs, cannabis, tobacco or nicotine, and alcohol for different reasons, including
- medical purposes
- religious or ceremonial purposes
- personal enjoyment
- to cope with stress, trauma, or pain
Substance use is different for everyone and can be viewed on a spectrum with varying stages of benefits and harms.
This page was last updated September 3, 2026