The second edition of the Handbook of Depression provides a broad overview of topics pertinent to current research on depression. In breadth and depth, it is appropriate for researchers new to the field, although more seasoned investigators will likely benefit from particular sections. The book covers four primary areas: (i) descriptive aspects of depression, (ii) vulnerability, risk, and models of depression, (iii) depression in specific populations and (iv) prevention and treatment of depression. Although exhaustively covering such a broad subject in a single volume is nearly impossible, the Handbook of Depression is reasonably informative with regard to the specific topics discussed.
Portions of the first section are rather general, and thus most helpful for those completely unfamiliar with the epidemiology and course of depression. In particular, chapter 3 describes a wide range of assessment techniques, providing strengths and weaknesses of different approaches. The next chapter covers methodological concerns in the study of depression, and does a nice job of articulating differences among conceptual and practical approaches to depression research and their potential consequences; for example, how do dimensional versus categorical interpretations of depression affect study selection criteria? Subsequently, how might results obtained using different study populations influence our overall interpretation of the aetiology of depression?
Other topics covered in the first section of the book include the relationship between depression and personality or medical illnesses, as well as a comparison between unipolar depression and bipolar depression. The latter is the first evidence in the book of an effort to include passages about bipolar depression. These sections are interesting and well written; however, the overall effort to include them seems inconsistent. Furthermore, while there are certainly parallels between unipolar and bipolar depression both at the level of behavioural manifestation and underlying biology, our current understanding of these similarities is still lacking. Perhaps these sections would be better suited in a text whose primary topic is bipolar disorder.
The second section of the text begins with an overview of the current understanding of the genetics and neurobiology underlying depression. The author of the section on genetics takes the reader on a whirlwind tour of different approaches to the genetic dissection of psychiatric disorders, briefly covering genetic epidemiology, candidate gene association studies, and linkage analyses. The focus seems to be the role of the serotonin transporter: readers unfamiliar with the field might be given the impression that few other genes are thought to contribute to vulnerability to depression, which is certainly not the case. However, given the influence of studies on gene×environment interaction at this locus, perhaps its central role in the chapter is warranted.
The chapters with a biological bent are well integrated with subsequent chapters in their common theme of risk and vulnerability. The understanding that both endogenous biology and exogenous environment influence risk for and course of depression is implicit. The chapters on neurobiology and emotion are especially articulate in their explanations of how these factors influence, and are influenced by, depression. The remaining chapters in the second section of the book discuss how depression affects relationships, from the perspective of both the individual suffering from depression and those who interact with that person; how these interactions can further influence the course of depression is also discussed.
The third section of the Handbook of Depression provides information on differences in depression across populations, a topic relevant both to clinicians and researchers. First, the experience of depression in different cultures is discussed. The authors note that depression is conceptualized differently across cultures, with some emphasizing somatic symptoms and others emphasizing social concerns such as relationship problems. Although some attention is paid to immigrant populations in the USA, much of this chapter is devoted to differences between Western and Asian populations. It is evident that the field could benefit from additional resources in this area of depression research.
Most of the additional chapters in this section deal with differences in depression across the lifespan. Together, these chapters illustrate the ontogeny of depression, noting differences in potentially influential factors, the manifestation of, and the definition of depressive pathology in childhood, adolescence, and late life. While the descriptions are not exhaustive, they provide the reader with enough information to encourage critical thought about what depression really means throughout development.
The final section of the book reviews a variety of approaches for prevention or treatment of depression. Many methods are covered, including interpersonal therapy, cognitive behavioural therapy, and pharmacotherapies; and the authors often provide general guiding principles regarding when a particular kind of therapy might be indicated. Furthermore, the usefulness of marital or family therapy is discussed, which ties in nicely with previous chapters that reviewed how one family member's depression affects other family members.
However, a degree of repetition is evident in this section that is also present in earlier sections of the book. In this last section, there is a good deal of overlap among chapters in terms of the therapies they cover. In previous sections, multiple chapters (somewhat superficially) address depression in children, gender differences in depression, and the biological underpinnings of the disorder. Such redundancy can be tiresome to read in any case, but particularly given that there are chapters in the book whose sole purpose is to review these subjects. Increased editorial oversight would likely reduce this problem so common in edited volumes.
Overall, the second edition of the Handbook of Depression is an informative text for newcomers to the study of depression. Each chapter concludes with a passage suggesting future directions for research, and most chapters are clear enough in their purpose and descriptions that the reader is not alienated by unfamiliar terminology even in areas outside his/her expertise. The breadth of topics covered is impressive, their sequence is logical, and chapters within a section are well integrated. Researchers across disciplines should find it a useful introduction to our current understanding of depression.
