 This project will introduce a self-help parent training programme for families on National Health Service NHS waiting lists for child mental health services. It will examine whether access to treatment can be increased by providing an intervention that requires fewer resources and by releasing clinician time for more serious cases. This intervention will be tested in a randomised, controlled trial in which 35 subjects will receive treatment immediately and 35 will receive treatment after waiting for 10 weeks. All families will also complete questionnaires before and after the 10 week study period in order to measure changes in child behaviour, parenting, and parental mental health. Cost-effectiveness of this programme will also be analysed. Intention-to-treat analyses will be conducted. 