This research will adopt a life course approach to the assessment of child mental health outcomes and associated costs. Primary analyses of the Avon Longitudinal Study of Parents and Children (ALSPAC) will be conducted to identify the natural history of child anxiety problems into early adulthood, and quantify their lasting effects - over the life cycle - in terms of educational attainments, adult health, employment and, if possible, associated health and social care use, and productivity costs.