Background Before a forensic addiction treatment can be ordered by the court according to sec. 64 of the German Criminal Code (StGB), a prognosis of success must be made and affirmed. In recent years, several studies have been devoted to the search for appropriate predictors of a "sufficiently concrete" prospect of success. Legal probation after release is the legally stipulated criterion for success in forensic addiction treatment. Objective As the second part of a two-part review on the determinants of success in forensic addiction treatment, this paper aims to provide an overview of the current evidence on predictors of legal probation after forensic addiction treatment and relates this to the evidence to the predictors of the discharge mode. Methodology Based on systematic literature research, the results of eight empirical studies published between 2002-2019 were processed in depth and presented in an overview table. Results Despite heterogeneous findings in detail, the presence of motivational, practical life and social resources, on the one hand, and criminal history and characteristics of current delinquency, on the other hand, show relatively clear relationships to legal probation after successful forensic addiction treatment. At the same time, the exclusive consideration of legal probation as the only criterion for the prognosis of treatment success reveals conceptual imprecision, since this is then overlaid by the criminal prognosis. Conclusion The limitations of the current state of research suggest a two-step approach for the preparation of a treatment prognosis: first, the predictors of the discharge mode could be used to examine the question of the likelihood of success of a regular course of treatment; then, the predictors of legal probation could be used to examine whether any conclusions can be drawn on the relapse-preventive effect of forensic addiction treatment. Both parts of the review can thus support forensic psychiatric experts in making a reliable prognosis of treatment prospects. In addition, consideration should be given to whether the information base for experts could be improved, for example, through a probationary phase.
