Are there important continuities between depressive episodes in childhood, adolescence, young adulthood, middle age and later life? Is the categorisation of depression by the age of the sufferer a reflection of the division of the Royal College of Psychiatrists into child, adult and old age faculties? Or are there genuine differences in aetiology, pathogenesis, clinical features, response to treatment and outcome for each life stage? Will an examination of the continuities and dislocations of these dimensions in relation to a person's life history be illuminating, or will it lead us into a conceptual morass?

Professor Goodyer brings the developmental perspectives of child psychiatry to one of the most pervasive and cumulatively disabling of mental disorders. He has commissioned six concise and expert reviews of our knowledge about depression at each life stage. These are sandwiched between two editorials, which try to move towards inclusion and integration of the developmental concepts of human growth and ageing. A third of the book's 200 or so pages are taken up by references. The chapter by Birmaher & Rozel covers childhood depression in just 10 pages, stressing the importance of comorbidity and complex psychosocial environments for this group. Harrington gives a masterly but necessarily skeletal review of research into every aspect of adolescent depression. Paykel & Kennedy provide an excellent but painfully condensed 15 pages covering depression between the ages of 40 and 60, and O'Brien & Thomas offer a fascinating summary of depressive disorders in later life, highlighting the increasing role of neurobiological changes in risk processes at this time.

There may have been variable latitude in the brief given to authors: for example, Lewinsohn & Seely, writing under the heading of ‘early adult life’, devote all of their 22 pages to their own Oregon Adolescent Depression project. Depression between the ages of 25 and 40 meets a cruel fate, having no coverage at all. In a chapter entitled ‘Intergenerational transmission’, Murray & Cooper document the impact of maternal depression on infant and child development, but their focus is on cognitive and behavioural outcomes rather than on depressive disorder in the offspring.

The most compelling parts of this book are the detailed accounts of the rare longitudinal cohort studies that examine transitions across life-span boundaries; illustrating the differences between risk processes at first onset and recurrence, and introducing the concept of critical periods for the activation and interaction of risk factors in biological and psychosocial domains.

Does Goodyer's strategy work? The answer may depend on the life-span perspective of the reader. Child psychiatrists will be pleased with the detailed treatment of their field and the useful (if extremely condensed) reviews of depression in other age groups. Adult and old age psychiatrists may be frustrated by this condensation, and by their own lack of sophisticated understanding of technical issues in the earlier chapters. Those who succeed in keeping the full breadth of material in focus will be rewarded by glimpses of the power of the life-span approach - which, it seems to me, is an idea whose time has finally come.