Evaluation of the Incredible Years Series - an open study of its effects when first introduced in Sweden.

Behaviour management problems (BMP) are common among children (4-12%) and the prevalence seems to be rising. Persistent antisocial behaviour often leads to poor long-term psychosocial adjustment. Structured parent-training programmes have proven to be the most effective way of treating BMP in young children. The Incredible Years Series (IYS), which is a manual-based programme, was introduced in Sweden in 2001. The aim of the present study was to evaluate the effectiveness of IYS in diverse clinical settings in Sweden. Parents of 113 children (3-9 years), recruited through the IYS-trained group leaders' ordinary services, participated in the study. The parents answered various questionnaires regarding their children's symptoms and their own psychological well-being before and after participating in the parent-training groups. The results are very encouraging; significant reduction of BMP in the children was found on all relevant measures. A significant increase in the self-rated well-being of the mothers was also found. The IYS seems to work in Sweden, even when used by group leaders who are in training. The importance of using a well-documented manualized method when implementing new models is accentuated.