This book charges current psychiatric practice with overdiagnosis of major depressive disorder, by including ‘normal’ reactions to losses. The authors note that big pharmaceutical companies have much to gain from casting the diagnostic net wide, and that sales are going up. They identify one, or the chief, culprit as the move in the Diagnostic and Statistical Manual of Mental Disorders (DSM) to descriptions of symptoms and syndromes regardless of context. The upshot, they argue, is that mood and behaviour may satisfy the DSM criteria for major depressive disorder even though they are normal responses to a significant loss (including, but not only, bereavement).

Clearly a lot – everything – hangs on how the authors differentiate ‘normal’ sorrow from ‘genuine mood pathology’. Their proposal is that normal sorrow has three features, in brief: (a) it has an appropriate object, i.e. loss; (b) its intensity is proportionate to the extent of loss; and (c) it fades as normal adjustment recovery mechanisms come into play. Pathology is then indicated by failure of one or more of these conditions. According to the authors, this way of differentiating normal sorrow from depressive disorder follows from Wakefield's influential evolutionary theoretical conceptualisation of mental disorder. I doubt this, but in any case the main implication is that diagnosis of genuine depressive pathology would have to establish whether the individual with symptoms was reacting to a loss in a proportionate way and for about the right length of time. This, as Robert L. Spitzer notes in his foreword, would present serious challenges to the reliability of diagnosis.

However, there are other problems with the authors' approach. The DSM's conceptualisation of mental disorder assigns primary importance to distress, disability or risk thereof; these in turn are connected, of course, to perceived need to treat (or to wait watching). In this context of (unmanageable) distress, downturn in functioning or risk, it is questionable whether the normality of mood – in the sense of understandable in relation to context – plays a critical role. We may well be able to understand, somewhat or well enough, why a single parent with little social support and a history of significant losses should become depressed, with distress and disability. Why should they, nevertheless, not be offered treatment? So far as I can see, clinicians have little use for the distinction between normal and abnormal depression except in the sense that normal may be used to mean: self-limiting, unlikely to carry risk, and no need to treat. Contextualising is less the issue: harm, risk and need to treat are.

The issue identified by the authors – increase of pathologising and prescribing – is serious and current; and they make clear one key possible diagnosis, that the limits of pathology are being illegitimately stretched. The authors are expert in this position and their book is essential reading for anyone concerned with these problems. This remains so even if there are differentials, for example that methods of detection have improved, and/or that there is no lower limit on the extent of distress and disability that we will take to the clinic in hope of help, especially if encouraged, for instance by direct-to-consumer advertising.