Table 2 Description of the training programmes

The training programme was originally developed to cope with alcohol addiction among adults in voluntary treatment, and was quite successful in that setting. It was because of a question by a JJI practitioner that this particular project was transformed for juveniles - and to include cannabis - and subsequently brought to that particular JJI. This practitioner felt that the low invasiveness of the training programme - short sessions behind a computer during which the participant pushes away and pulls certain images - would be suitable for the JJI context, as the adolescents are poorly motivated to confront their addiction.

A larger roll-out of this research happened after it was coupled to the second research component about neurobiological predictors of recidivism, by measuring heart rates and hormones in saliva. This research revolves more around a proof of principle and there is greater uncertainty on its benefit for the JJIs later on. It is noteworthy, however, that the research question emphasises the added value of neurobiological predictors compared with existing measures in the JJIs. If neurobiological measures can predict recidivism, the principle has been proven. They can still be deemed unsuccessful if they do not outperform existing measures in the JJI