Objective: To examine changes in symptoms of oppositional defiant disorder (ODD) after treatment with the Incredible Years Program. The frequency of symptoms was also calculated.
Method: The participants were 84 children (aged 4.1-8.9 years) diagnosed with ODD before treatment. The data were collected with KIDDIE-SADS interviews before treatment and at a 1-year follow-up.
Results: At the 1-year follow-up, descriptive analyses showed that 68% of the children no longer had an ODD diagnosis. Even though all the ODD symptoms had been significantly reduced after treatment, most symptoms still occurred "sometimes".
Conclusions: The Incredible Years Program has a positive effect on children with ODD. However, many children still have symptoms of ODD at the 1-year follow-up, although the frequency of symptoms is significantly reduced. Future studies should explore further these changes in ODD symptoms and evaluate whether some parents and children need support in addition to the Incredible Years Program. It would also be valuable to determine whether patterns of childhood ODD symptoms are related to later development of depression and conduct disorder.