In recent years increased anxiety has been expressed about the apparent deterioration in children's social and emotional well-being in contemporary Western society. This anxiety has stimulated significant investment by governments and other agencies in policy initiatives and programmes aimed at promotion of children's mental health and early identification of mental disorder. A widespread consensus has emerged that the school is a 'natural' setting for such intervention, and so the best place to target resources and effort. Almost universally it is assumed that such initiatives are an unequivocal 'good'. This challenges both assumptions, and offers a critical social scientific analysis of policy developments in the UK with particular reference to power, politics and the implications for children's rights.