Registered Nurses' Association of Ontario

Substance Use Definition and Classification Criteria

  • Substance use refers to the ingestion or administration of psychoactive substances (i.e. alcohol, tobacco, caffeine, illegal drugs, medications, solvents, and glues) that can be beneficial or harmful depending on the substance used, quantity, frequency, method, and context of use (Ministry of Health Promotion, 2010; Rassool, 2010).
  • The Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM–5; American Psychiatric Association [APA], 2013), defines a Substance Use Disorder as “a cluster of cognitive, behavioral, and physiological symptoms indicating that the individual continues using the substance despite significant substance-related problems” (APA, 2013, p. 483).
  • In this Guideline, the term “substance use disorder” will be used to indicate those at risk for problems associated with substance use, as well as those who meet the DSM-5 criteria for a substance use disorder.
Addiction and Mental Health
Engaging Clients who Use Substances
Background Information