Effective correctional treatment

Research summary
Vol. 10 No. 2
March 2005


How much treatment is required to reduce reoffending?


Almost all incarcerated offenders are eventually released back into the community. The most effective treatment programs follow three basic principles: 1) treatment provided to offenders who are at higher risk to reoffend is more effective than treatment provided to lower risk offenders; 2) treatment programs that target those needs associated with criminal behaviour (i.e., criminogenic needs) such as antisocial attitudes, substance abuse, and associations with criminal peers, are more effective than treatment programs that target needs such as anxiety, self-esteem, or depression (i.e., non-criminogenic needs); and 3) treatment programs are more effective when they are delivered in a way that is responsive to the offender's style of learning, using cognitive-behavioural interventions that change attitudes and teach concrete skills. However, there is little evidence indicating how long these treatment programs need to be in order to have an impact. In other words, what 'dosage' of treatment is required for an offender in order to reduce his/her chances of reoffending?


The recidivism rates of 620 offenders who received either no treatment, 100, 200, or 300 hours of treatment over the course of 5, 10 and 15 weeks, respectively, were examined. Offenders' risk to reoffend and criminogenic needs were assessed, and offenders were then assigned to different levels of treatment intensity (e.g., low risk/need offenders to 100 hours of treatment and high risk/need offenders to 300 hours). However, some offenders received less treatment than prescribed due primarily to not having enough time left in their sentence to complete the lengthier program. Treatment programs were cognitive-behavioural and targeted substance abuse, criminal attitudes, aggression, and criminal peer associations.

The participants for this study were offenders incarcerated in a provincial facility and followed up for one year after release. Statistical analyses examined the varying level of dosage on offenders of different levels of risk and need.


A follow-up of the offenders found that 31% of those who participated in treatment recidivated, significantly less than the 41% of the offenders who had no treatment. Results indicated that offenders with different risk/need levels required different amounts of treatment in order for it to have an effect.

For high risk offenders, with many criminogenic needs, 300 hours of treatment reduced recidivism from 59% to 38%. For these types of offenders, 100 hours of treatment was insufficient to reduce recidivism.

For medium risk offenders with few criminogenic needs, 100 hours of treatment was sufficient to reduce recidivism from 28% to 12%. For these types of offenders, more treatment was not associated with any further reductions in recidivism.

For high and medium risk offenders with a moderate number of criminogenic needs, 200 hours of treatment was sufficient to reduce recidivism from 44% to 30%.

Policy implications


For further information

Guy Bourgon, Ph.D.
Corrections Research
Public Safety Canada
340 Laurier Avenue West
Ottawa, Ontario K1A 0P8
Phone: 613-991-2033
Fax: 613-990-8295
E-mail: Guy.bourgon@ps-sp.gc.ca

Date modified: