This book explores a method, the longitudinal study, and the rich harvest it has yielded for the practising professional and for students in the social and medical sciences. The thirteen studies examined here range in origin from Sweden, Britain and the United States and demonstrate considerable variety both in character and in the lessons that can be drawn from them. The common theme is the examination of the interface between research and practice. Aimed at practitioners and students in training, interested in appraisals of modern theoretical perspectives in developmental psychology and psychiatry as applied in practical research, the book shows how a variety of longitudinal research designs can be applied and the type of data they yield, and to help the student and practitioner to evaluate research data critically and draw practical conclusions from them.

This book is about the difficulties encountered by mothers and toddlers in the preschool years, and the effectiveness of professional help. We report a major research project which consists of three approaches to intervention: intensive health visiting, family therapy and mother and toddler groups. The core of the book is a trial of how these approaches affect child disorder, mothers' mental health, child development and the state of the marriage. In the early chapters, the study is placed into the context of current thinking and research, considering issues in child and family development. Chapter 2 focuses on the main variables of the study and considers how psychopathology may develop over this period and bring together evidence on its outcome. In doing so, it builds the case for intervention both by looking at how problems begin, how this relates to the development of the child and family generally, and in turn what effects these problems have on development. Chapter 3 describes approaches to helping preschoolers and the contexts in which these have been tried, leading to studies of the effectiveness of intervention.
In the final three chapters, research findings on the practical and academic implications of the work are discussed.