The effectiveness of Prisoners Addressing Substance Related Offending (P‐ASRO) programme: evaluating the pre and post treatment psychometric outcomes in an adult male Category C prison

Offending behaviour interventions that adhere to the now well‐known principles of “What Works” can be effective in reducing recidivism. The field is dominated by a programmed approach, in which facilitators adhere to a manual designed to target specific criminogenic needs and risks in different groups of offenders. This study aims to explore the short‐term impact of the Prisoners Addressing Substance Related Offending (P‐ASRO) programme, a cognitive‐behavioural intervention addressing offending related to substance misuse and targeting those with low‐medium dependency. The aim of this paper is to evaluate the impact of P‐ASRO in key areas targeted by the programme.

A non‐experimental fixed design examined differences between the pre‐ and post‐intervention measures of prisoners (n=81) who had completed the P‐ASRO programme between April 2006 and March 2007.

The majority of offenders in the sample fell into the high‐dependency need group. Nevertheless, there were significant differences between all of the pre‐ and post‐measures, with large effect sizes reported. Prisoners were found to be less impulsive, to have increased their problem‐solving ability, to have developed a greater internal locus of control and were more motivated toward taking action.

Caution needs to be taken in relation to the conclusions that can be drawn due to the nature of the data used (anonymised archival data) which do not allow for the control of certain key variables.

The findings add to the research on prison interventions and lend some support to the suitability of this intervention for offenders with substance use problems, regardless of severity of substance dependency.