ObjectiveThis study investigated the effects of a school-based skill-training intervention in attention control and executive functions for pupils with hyperactivity-impulsivity and cognitive control deficits. The main aim was to examine whether the intervention differently influenced H-I and CC, and whether cognitive abilities or conduct problems moderated response to the intervention.MethodElementary school pupils from 41 schools participated the study and were divided into an intervention group and a waitlist control group. Intervention outcomes were assessed with an inventory assessing executive function difficulties (...) completed by classroom teachers.ResultsSignificant intervention effects and positive changes were detected in CC but not in H-I. Significant intervention effects were found mainly among pupils with low levels of conduct problems.ConclusionsThe results suggest that a skill-training intervention has specific positive effects on CC, but conduct problems may diminish response to intervention. (shrink)