Depression is a leading cause of psychiatric morbidity. Some 10 to 15 per cent of the population worldwide is estimated to have had at least one serious episode in which normal responses to grief or loss became pathologically severe and persistent. Treating depression is therefore the main occupation of most psychiatrists, psychologists and other mental health workers, and is, of course, a major source of business for the pharmaceutical industry. Currently approximately 8 per cent of the American population are estimated to be taking antidepressant drugs. While the rate of diagnosis is rapidly rising, the evidence as to whether the disorder is becoming more prevalent is, at least, unclear. It has been suggested that much of this increase in diagnosis is due to the growing habit, both of professional mental health workers and of the general public, of regarding what used to be accepted as “normal” reactions to life as disorders needing treatment. The expectation that we should all be happy all the time is a very recent development in human history, and may be masking the constant level of a real and crippling disorder.
The fact that, even more than is the case with other mental disorders, there is no clear dividing line between “normal” and “ill” makes research into depression rather difficult. The American Psychiatric Association's Diagnostic & Statistical Manual had to lay down astonishingly arbitrary rules – “a minimum five symptoms out of a check‐list of nine, present for a minimum of 14 days” to attempt a classification. Remarkably little is known about depression. There is clearly a strong genetic element, details of which are only just beginning to be disentangled. Traumatic life events obviously play a major part in triggering off attacks. There is a very strong relationship with other mental disorders – people with schizophrenia are three times more likely to also suffer from depression than the general populace. Anxiety, stress and eating disorders show so many overlapping symptoms that it is hard for even the most rigid diagnostician not to see them as aspects of a general spectrum. Being ill in general is depressing, but there is a high level of co‐morbidity between depression and arthritis, or certain skin disorders, for example. Most especially there is a strong relationship between substance abuse and depression, though the nature of the relationship is complicated and unclear.
In spite of this high level of ignorance, the literature on depression is enormous. This is the first encyclopedia I have come across, but there are lots of large handbooks and other multi‐authored reference books on the market. The standard‐bearer, in my opinion, is the Handbook of Depression (Gotlib and Hammen, 2009) and my classic choice would be Handbook of Affective Disorders (Paykel, 1992). There is a third edition of Depressive Disorders (Herman et al., 2009) out. I have not seen this yet, but the previous editions were crammed full of useful compacted information. In the broader field I have also heard well of the new Oxford Handbook of Anxiety & Related Disorders (Antony and Stein, 2009) which sounds like an essential tool for psychiatric libraries. There are plenty of handbooks and major textbooks on particular aspects of the disorder, such as the Handbook of Depression in Children & Adolescents (Abela and Hankin, 2008), the Hypomania Handbook (Doran, 2008), the Handbook of Research in Emotional and Behavioral Disorders (Rutherford et al., 2004) and, notably, the Clinical Handbook of Co‐existing Mental Health and Drug and Alcohol Problems (Baker and Velleman, 2007). There is not, as far as I am aware, a major reference book on genetics and depression, but the rate of research in the field is so rapid at that it will soon be time for a major summing‐up: there is clearly no single “gene for depression” any more than there is for most other disorders (last time I counted there were 137 “genes for schizophrenia” and the number is still rising). The entry here provides a very neat and succinct summary of this complex topic.
Faced with this enormous array of reference literature we have to ask ourselves whether we need an encyclopedia on the subject, and whether many libraries need to spend £127.50 on buying it. I regret to say that, in spite of the undoubted quality of the entries in this book, I remain unconvinced. There are some subjects that lend themselves to arrangement in English alphabetical order. They cover a clearly identified field that divides neatly into discrete sub‐topics that can be defined and discussed in short, largely self‐sufficient entries, using the minimum of cross‐referring to bring different topics together. Even then they only work well if great care is taken in selecting the alphabetic headings. Depression seems to me to be a subject that calls for a handbook arranged in topic order, rather than an alphabetical encyclopedia.
This problem is illustrated by the very first entry in the book, Aaron Beck. This is just silly. Beck is a very important figure in the history of the psychological treatment of depression, but putting him by first name under A, putting the Beck Depression Inventory under B and putting the cognitive therapies he pioneered under C is not helpful to the reader. This situation is not eased by the fact that many of the entries are quite long. The decision as to which subjects get entries, and which are subsumed under a main entry seems somewhat arbitrary. I can see why Glucocorticoid Signaling in the Brain is a subheading under H for Hypothalamic‐Pituitary‐Adrenal Axis but if I was an enquirer with an interest in gluticocortoid receptors looking up the topic in an encyclopedia I might well have looked under G, where there is no cross‐reference to guide me. Lengthy, multi‐authored, sub‐divided articles really belong in a handbook not an encyclopaedia. The sub‐division headings are in the same size and boldness of type as the main headings. They are slightly italicized but the distinction is not sharp enough to make it clear to casual enquirers where they are in the alphabetical sequence. You really have to use the contents list and index to navigate your way around this book, in which case it might as well have been arranged in a useful subject order rather than alphabetically.
This is a very American book. There is one British member among the 11‐strong editorial team, as well as a token Canadian, but the vast majority of the 250 contributors are American professionals. This does not greatly matter. The incidence (though not the expression) of depression does not seem to differ between countries, and much of the scientific research is American. It has to be noted however that American doctors are under even more pressure to diagnose pharmacologically treatable disorders than doctors in other countries – “What is the difference between a psychiatrist and a librarian?” (Guha, 2009). Rather more importantly, this is a professional book. It is written by highly qualified mental health clinicians and academics, for a readership of mental health clinicians and academics. The voice of the patient goes completely unheard. This really is a major omission. A large proportion of all cases of depression are not treated by mental health professionals. A study in St Thomas' Hospital suggested that of the 105,000 individuals who attended the Accident & Emergency Unit in one year, approximately 38,000 had an undiagnosed mental health disorder, mostly depression (Guthrie and Lloyd, 2007). The numbers who do not get as far as A&E is probably equally great. Even in America there are a very large number of people who do not have medical insurance which would cover them for treatment by the contributors to this book. Even among those who are covered by such insurance there is ample evidence that they also make extensive use of treatments not discussed here “One of the most rapidly expanding sectors of the economy is the trade in non‐prescription complementary medicines” (Guha, 2010). There is no discussion of complementary or alternative health care in this book – just a fleeting disparagement under Human Immunodeficiency Virus' advising against the use of St Johns Wort, and no mention of yoga at all, for example. The fact that these treatments are being used by large numbers of people makes them worth a serious discussion.
Having disparaged its arrangement and the limitations of its content, I should emphasise the high quality of the articles in this book. The individual entries are well written, by skilled professionals. Mental health workers – psychiatrists, clinical psychologists, etc. will find the latest scientific information on depression clearly and accurately summarized in a solid mass of well‐referenced articles here. If this were rearranged as a handbook I would be recommending it to all psychiatric libraries, and suggesting that medical libraries in general should consider it. As an encyclopedia, I am less certain of its value.
