Proportion of crimes associated with alcohol and other drugs in Canada

Kai Pernanen, Marie-Marthe Cousineau, Serge Brochu and Fu Sun
Canadian Centre on Substance Abuse
April 2002

Reviewed by:

Dr M Y Morgan, Reader in Medicine, Royal Free Campus, Royal Free and University College Medical School, London, UK

The relationship between alcohol and crime is complex. Although there is evidence of an association between alcohol and offending behaviour, the nature and extent of this association is still a matter of debate. Most people who consume alcohol do not offend, and most offenders are not under the influence of alcohol at the time of their offence. However, it is clear that much criminal behaviour occurs while the offender is under the influence of alcohol and offenders are more likely to report having an alcohol problem than non-offenders.

The relationship between illicit drug use, crime and offending is equally complex and, perhaps, even more difficult to unravel. The fact that many individuals who use or misuse illicit drugs also use or misuse alcohol further confounds the problem.

The Present Study

Very little information is apparently available on the association between the use and abuse of illicit drugs and alcohol and the commission of criminal acts in Canada. In consequence, the Canadian Centre on Substance Abuse initiated a set of studies aimed at estimating the proportion of crime in Canada attributable to alcohol, cannabis, heroin and cocaine use. For purposes of the analysis data were obtained from several sources, including surveys of federal prison inmates, provincial prison inmates and arresting police officers.

The authors are well aware of the methodological limitations of the work that they have undertaken and are aware that their findings can be questioned on several counts. They do, however, stipulate that the information provides useful rough estimates of 'what can be found in the field' and background information on which to base future research proposals.

1. Federal Inmate Study

Federal penitentiaries in Canada admit inmates sentenced to incarceration for a minimum of 2 years. Federal inmates have, therefore, generally committed more serious crimes than those in provincial penitentiaries. Two studies were undertaken among federal inmates:

The CSC Study

All new Federal inmates are assessed in order to define their treatment and other individual needs. Data are collected on various aspects of health, relationships, drug and alcohol use and criminal activities using a Computer Lifestyle Assessment Instrument (CLAI); the alcohol dependency scale and a drug addiction severity tests are included in the CLAI instrument.

Data collection takes 2 hours on average and only literate individuals would presumably be able to complete the task although this was not specified. Data collection on CLAI started in 1989 but the authors of the report chose to analyse the data collected between 1993 and 1995 as it provided 'best geographical coverage'; this is not further explained. During this period 14,263 individuals were eligible to complete the CLAI instrument but data were only available on 8,598 – representing approximately 60% of the total eligible sample. Coverage was extremely variable being as low as 27% in the Prairie Province up to 85% in the Quebec Province.

The FII Study

These data were collected primarily in 1999 and 2000. A total sample of 760 inmates was identified; 582 were approached and valid interview data were available from 469 individuals, which represents 81% of the sample approached but only 62% of the total sample. This study incorporated central questions from the CSC study on the use of drugs and alcohol and criminality and used the same tests for dependence on alcohol and drugs.

They also used a questionnaire that probed alcohol and drug use, criminal activities and important life events during the 3 years preceding the inmates' latest arrest. The inmates were required to fill in the questionnaires themselves while the interviewer and inmate co-operated to obtain the data for the 3-year calendar instrument.

2. Provincial Inmate Study

The methodology for this study mirrored that of the FII Study. In total, 129 women were asked to participate of whom 100 (78%) consented; a total of 137 male inmates were approached for interview of whom 100 (75%) consented. Interviews were conducted during 2000.

3. Study of Arrestees

Information was collected on arrests made in 26 Canadian locations during a 1-month period in mid-2000. The data were collected by police officers and were based on information available to them at the time of the arrest. The arresting officer noted if the arrested person was an 'abuser of alcohol' or an 'abuser of illicit drugs'. However, while they were definitely certain that the individual arrested was under the influence of alcohol in 73% of cases they were only definitely certain that the individual arrested was under the influence of drugs in 34% of cases. Data were available, overall, on 334 women and 1,544 men.

Calculation of Attributable Fractions

The data collected in these Canadian studies are based on population of individuals who, by definition, have committed a crime. This places considerable restrictions on the type of analyses that can be made. Considerable manipulation of the data were, therefore, necessary in order to arrive at a final, corrected - intoxication/economic – compulsive model for determining attributable fraction estimates. Great care must, therefore, be taken in the interpretation of the results.

Study Results

The main findings in this report are:

  • Slightly more than half of federal inmates reported having used illicit drugs during the 6 months immediately prior to their last arrest. Almost 66% of both male and female inmates in the provincial prisons had used drugs during the same period. Cannabis was the most frequently used drug by the federal inmates having been used by 43%, whereas 28% had used cocaine and 7% heroin.

  • Few data are available on the prevalence of drug use in the general adult population in Canada although in one survey 8% of adults had used drugs in the preceding 12 months.

  • Care must be taken, however, in the interpretation of these data because there is significant geographical variation in the prevalence of drug use in Canada with much higher figures observed in Quebec Province.

  • Over 80% of inmates had used alcohol in the 6 months prior to their last arrest. This equates with the figures observed in the general adult population of Canada.

  • The use of drugs and alcohol on the same occasion was prevalent; 40% of federal inmates reporting combined drug and alcohol use during the 6 months prior to their arrest.

  • Between 13-16% of federal inmates were dependent on alcohol. Between 31-40% were dependent on one of more illicit drugs. Thus, overall between 38-44% of male federal inmates were dependent on at least one psychoactive substance. The proportion of alcohol and drug dependent inmates was similar in both federal and provincial prisons.

  • The proportion of relatively serious crimes that were in a significant way determined by the use of drugs and alcohol in Canada was estimated to be:

    • Illicit drugs only 10-15%

    • Alcohol only 15-20%

    • Combines use of drugs and alcohol 10-20%

    • Any psychoactive substance 40-50%

  • The proportion of less serious offences that are in a significant way determined by use of any psychoactive substance was 64% which is not surprising as alcohol- and drug- specific offences such as drink driving, drunk and disorderly, offences against licensing laws, drug possession, drug trafficking and drug manufacture were included in this figure

Thus, while this research evidence points to a link between illicit drugs, alcohol and offending behaviour the research base is limited and subject to considerable methodological limitations. Further research is required to more fully explore the complexities of the relationship and how this may differ in relationship to the type of offence committed and the cultural and social context of offence perpetration.

It is clear that the links between drugs, alcohol and crime cannot be looked at in isolation but need to be reviewed in relationship to their interaction with a number of individual, constitutional, social, cultural and situational factors. It is to be hoped that these workers will eventually undertake the well-designed, analytic studies needed to determine the relative and absolute risks of criminal behaviour associated with alcohol and drug use and misuse.