Offender Substance Use Patterns – Aboriginal and Non-Aboriginal Offenders

Key Words

Substance use, Aboriginal and non-Aboriginal offenders, computerized assessment


Offenders are assessed for substance abuse problems when they arrive at federal correctional institutions using the Computerized Assessment of Substance Abuse (CASA). The CASA incorporates standardized alcohol and drug screening instruments to identify problematic use of alcohol and other drugsFootnote 1. It is known that Aboriginal offenders are overrepresented in the correctional system and are rated as having higher needs than non-Aboriginal offenders. The purpose of this research is to provide an updated examination of substance use patterns of Aboriginal and non-Aboriginal offenders.

What we did

In total, 15,164 male offenders completed the CASA between fiscal year 2006/07 and 2010/11Footnote 2. We compared Aboriginal and non-Aboriginal offenders on age of first use, level of substance use severity, drug of choice, and poly-substance use for the 12-months prior to arrest.

What we found

  • Aboriginal offenders were younger than non-Aboriginal offenders when they first tried alcohol (13 years vs. 15 years) or drugs (15 years vs. 16 years).
  • 86% of Aboriginal offenders had an identified substance use need compared to 68% of non-Aboriginal offenders (Figure 1). More specifically, 56% of Aboriginal offenders and 37% of non-Aboriginal offenders would require intensive programming.
Figure 1. Severity of substance dependence

This bar chart compares the distribution of severity of substance use dependence among male Aboriginal and Non-Aboriginal offenders who completed the Computerized Assessment of Substance Abuse (CASA) between April 1, 2006 and March 31, 2011. 32.3% of Non-Aboriginal offenders were categorized as 'none' compared to 13.8% of Aboriginal offenders; 30.7% of Non-Aboriginal offenders and 30.2% of Aboriginal offenders were classified as 'low' severity; 14.2% of Non-Aboriginal offenders and 23.3% of Aboriginal offenders were classified as 'moderate' severity; and 22.8% of Non-Aboriginal offenders and 32.7% of Aboriginal offenders were classified as 'substantial/severe' severity.

Severity of substance dependence

  • For both groups, dependency was higher for drugs than for alcohol with 34% to 44% of offenders having moderate to severe drug dependency compared to 8% to 28% for alcohol.
  • Aboriginal offenders were more likely than non-Aboriginal offenders to report marijuana as their drug of choice (51% vs. 45%) while non-Aboriginal offenders were more likely to report cocaine (33% vs. 29%; Figure 2).
Figure 2. Substance used most 12 months prior to arrest

This bar chart shows the substances used during the 12 months prior to their current arrest for Aboriginal and Non-Aboriginal male offenders who completed the Computerized Assessment of Substance Abuse (CASA) between April 1, 2006 and March 31, 2011. Marijuana/hashish use was reported by 50.6% of Aboriginal offender s and 45.1% of Non-Aboriginal offenders. Cocaine/crack cocaine use was reported by 28.6% of Aboriginal offenders and 33.4% of Non-Aboriginal offenders, while similar proportions of both groups reported opiate use (12.8% for Aboriginal offenders and 12.2% for Non-Aboriginal offenders) and other drug use (8.0% of Aboriginal offenders and 9.4% of Non-Aboriginal offenders). Substance categories are not mutually exclusive.

Substance used most12 months prior to arrest

  • Over half of all offenders (59%) indicated poly-drug use on the same day in the 12 months prior to arrest. Interestingly, Aboriginal offenders were more likely to combine the use of alcohol and drugs on the same day (59% vs. 51%).

What it means

The results demonstrate that almost three-quarters of offenders show some level of alcohol or drug dependence at admission and over half are poly-substance users. While Aboriginal offenders exhibited higher levels of dependency, the pattern of drug types used prior to incarceration is similar for Aboriginal and non-Aboriginal offenders. The findings indicate that substance abuse dependency is a significant area of need for male offenders upon admission. In order to ensure successful rehabilitation and reintegration, offenders require continued access to the necessary programming and treatment interventions to address this complex problem.

Prepared by: Peggy Mullins and Shanna Farrell MacDonald


Research Branch
(613) 995-3975


Footnote 1

Skinner, H. A., & Horn (1984). Alcohol Dependence Scale (ADS): Users Guide. Toronto, ON: Addiction Research Foundation. Skinner, H. A. (1982). The Drug Abuse Screening Test. Addictive Behaviours, 7, 363-371.

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Footnote 2

13% of offenders who completed the CASA during this time were Aboriginal.

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