5 semi-structured manualised MI sessions was conducted by existing prison staff having undergone 3 days of Motivational Interviewing workshop training and 2 days of training with the BSF manual.

5 semi-structured manualised MI sessions was conducted by ordinary prison staff having undergone 3 days of Motivational Interviewing workshop training and 2 days of training with the BSF manual, followed by ongoing Motivational Interviewing training with feedback based on audio taped sessions in peer supervision groups.

5 sessions was conducted by prison staff according to usual working practices, with the exception that content was structured into 5 sessions and audio recorded. The provision of a government decree served as a basis for the intervention, covering planning of prison activities and post release arrangements including strategies for drug use cessation.

MI is a communication style defined as a collaborative, person-centred form of guiding to elicit and strengthen motivation to change. The method is based on four principles: showing empathy; developing discrepancy between the subject's current behaviour and an alternate, more desired, behaviour; reinforcing self-efficacy; and "rolling" with resistance to change. Client arguments for change are elicited and reinforced in an atmosphere that is empathic, collaborative and supportive of autonomy. The choice to change and the responsibility for change remain with the client.

alcohol- or drug use as measured by the Addiction Severity Index (ASI) at intake and at 10 months after release

as measured by Addiction Severity Index at intake and 10 months after release

as measured by the Addiction Severity Index at intake and 10 months after release