The book is based on the treatment manual developed by the State Hospital (which was co-written by Bill Lindsay) but has been modified for use with offenders with developmental disabilities. The book is organised into modules, starting with practical advice on how to develop group dynamics and encourage participant ownership. Subsequent modules cover topics such as disclosure, dealing with cognitive distortions, the cycle of offending, victim awareness, pathways to offending and non-offending and relapse prevention. Particular attention is given to how to set up role plays, how to present material effectively and how to motivate the group. As well as CBT, new initiatives in offender rehabilitation such as self-regulation and GLM is covered.