Detecting effects of the indicated prevention Programme for Externalizing Problem behaviour (PEP) on child symptoms, parenting, and parental quality of life in a randomized controlled trial.

Background: Behavioural parent training is effective in improving child disruptive behavioural problems in preschool children by increasing parenting competence. The indicated Prevention Programme for Externalizing Problem behaviour (PEP) is a group training programme for parents and kindergarten teachers of children aged 3-6 years with externalizing behavioural problems.

Aims: To evaluate the effects of PEP on child problem behaviour, parenting practices, parent-child interactions, and parental quality of life.