Home > Investigating the links between substance misuse and crime.

Connolly, Johnny (2013) Investigating the links between substance misuse and crime. Drugnet Ireland, Issue 45, Spring 2013, p. 15.

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A report by the Probation Service presents the findings of the first large-scale, nationwide survey conducted by the service on drug and alcohol misuse among the adult offender population on probation supervision.1 Although earlier research in Ireland has highlighted a link between substance misuse and offending behaviour,2 the identification of the precise causal connection between drugs and crime remains a complex and much-debated area of criminological research.3 


A better understanding of the nature of the connection between drug use and offending has implications for drug and crime prevention and for treatment and criminal justice interventions. A major impediment to research in this area in Ireland, however, is the absence of data from within the criminal justice system. For example, it is clear from prison drug seizures, prison drug testing and methadone maintenance uptake in prison, that a significant proportion of Irish prisoners are problematic drug users.4
We also know from data provided in the annual reports of the Irish Prison Service the number of people imprisoned for drug offences under the Misuse of Drugs Acts, such as drug possession or supply. However, most problematic drug users are imprisoned not for breaches of the drug laws but for drug-related offences, that is, offences such as theft committed as a consequence of their addiction, to fund their drug habit. It is in highlighting this particular aspect of the drugs–crime nexus that this report is particularly important.

The survey involved a representative sample of 2,963 adult offenders on probation officers’ caseloads on 1 April 2011. Questionnaires, developed specifically for the purpose of the study were completed by the supervising probation officers, based on their case records and knowledge of the offenders on their casebooks.

The main objectives of the study were as follows:
• Ascertain the number of adult offenders on probation supervision who misuse drugs and/or alcohol.
• Examine the nature and frequency of drug and alcohol misuse.
• Establish if there is a correlation between drug and/or alcohol misuse and offending behaviour.
• Identify the level and nature of engagement with drug and alcohol treatment services.

Included among the key findings in relation to the first two aims (p.4) are the following:
·      89% of the adult offender population on probation supervision had misused drugs or alcohol either ‘currently’ (at the time of the survey) or in the ‘past’.
·      Of those who misused either alcohol/drugs, 27% misused drugs only, 20% misused alcohol only and 42% misused both drugs and alcohol.
·      While females comprised only 12% of the adult offender population, both male and female adult offenders exhibit similar drug and alcohol misuse levels.
·      The Dublin probation regions exhibited the highest levels of overall misuse among their offender populations, at 91%.
·      Almost 21% of offenders were currently misusing two or more substances and over 9% were misusing at least three substances. This includes misuse of alcohol.
Chapter five of the study considers the relationship between drug/alcohol misuse and crime among the adult offender population on probation. The study found that, based on the probation officers’ professional judgement, ‘there were a substantial number of cases where drug misuse (74%) and alcohol misuse (71.3%) were linked to the offence committed’, although the author adds the important caveat that the complexity of the issue meant that a ‘strong association’ between the drug use and the offence should not be interpreted as meaning that one necessarily caused the other (p.38). In this respect, and consistent with other research in this area, the study found that many ‘other factors associated with offending behaviour’, such as ‘the offender’s anger…mental health and mild learning difficulties…disrupted family background, lack of parental control, low education, child abuse and domestic violence were also stated as risk factors in offending behaviour’ (p.38).

With regard to gender issues, the study found that drug misuse among female offenders was marginally more likely to be linked to the offence than that among male offenders; the opposite was the case in relation to the link between alcohol and the offence committed. The study also found that the link between drug misuse and offending was more pronounced among the younger age groups. In terms of the offence type, of those whose drug misuse and offence were linked, 31% of offences were drug law offences (such as drug possession), while 36.8% were linked to acquisitive crimes (theft, burglary, robbery, property offences) (p.33). The study also highlights the link between alcohol and crime, particularly violent and public-order-related crime: the alcohol misuse of 71% of alcohol-misusing offenders was linked to the current offence committed, and the majority of alcohol-related offences were crimes against the person and public order offences, at almost 40% (p.37).
The final aim of the study was to consider treatment uptake among the offender population. It found that ‘of those who misused drugs, 48.4% appeared to be not currently engaging with any drug treatment service’ (p.42). It is unclear why this is the case as the views of offenders were not incorporated into the study, one of the acknowledged limitations of the research (p.8). Nevertheless, this study is an important contribution towards the development of evidence-based criminal justice interventions in response to crime related to drug and alcohol misuse.  
1.    The Probation Service (2012) Drug and alcohol misuse among adult offenders on probation supervision in Ireland: findings from the drugs and alcohol survey 2011. Navan: The Probation Service. www.drugsandalcohol.ie/18746
2.    Two important early studies are: O'Mahony P (1997) Mountjoy prisoners: a sociological and criminological profile. Dublin: Stationery Office; Keogh E (1997) Illicit drug use and related criminal activity in the Dublin Metropolitan Area. Research Report No. 10/97. Dublin: An Garda Síochána.
3.    For a discussion see Connolly J (2006) Drugs and crime in Ireland. HRB Overview Series 3. Dublin: Health Research Board.
4.    For a broader discussion on this issue see Health Research Board (2011) 2011 National Report (2010 data) to the EMCDDA by the Reitox National Focal Point. Ireland: new developments, trends and in-depth information on selected issues. Dublin: Health Research Board. Chapter 12.
Item Type
Publication Type
Irish-related, Open Access, Article
Drug Type
Substances (not alcohol/tobacco)
Intervention Type
Crime prevention
Issue Title
Issue 45, Spring 2013
April 2013
Page Range
p. 15
Health Research Board
Issue 45, Spring 2013
Accession Number
HRB (Electronic Only)

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