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BOOK REVIEW |
Clinical Coordinator and Director of Training Psychology Service VA Palo Alto Health Care System Palo Alto, CA 94304
Assessing and Treating Late-Life Depression: A Casebook and Resource Guide, by Michele J. Karel, Suzann Ogland-Hand, and Margaret Gatz (with Jurgen Unützer). Basic Books, New York, 2002, 243 pp., $45.00 (cloth).
Depression in Late Life (3rd ed.), by Dan Blazer. Springer Publishing, New York, 2002, 485 pp., $58.95 (cloth).
Physical Illness and Depression in Older Adults: A Handbook of Theory, Research, and Practice, edited by Gail M. Williamson, David R. Shaffer, and Patricia A. Parmalee. Kluwer Academic/Plenum Publishers, New York, 2000, 370 pp., $75.00 (cloth)
Depression as a mental health issue in older adults has been a focus of research and clinical interest for decades, so the knowledge regarding this disorder is cumulatively larger than for any other mental health problem in older adults. These three volumes provide a thoughtful, comprehensive overview of the state-of-the-art in understanding the causes of depression and treatment options in older adults. In so doing, the gaps in knowledge emerge along with the summary of what is known. I will begin with a short review of some of the multiple strengths of each book and the kind of contribution each makes. Then I will consider some cross-cutting issues and discuss priorities for further advancing our understanding of depression in older adults.
The first volume, by Michele J. Karel, Suzann Ogland-Hand, and Margaret Gatz, Assessing and Treating Late-Life Depression: A Casebook and Resource Guide, is a valuable clinical resource. The authors are all clinical geropsychologists, and the primary strength of this book is its presentation of an empirically supported psychological perspective to guide assessment and treatment. Further, the authors' intent, which is well carried out, is to place that psychological approach within an interprofessional framework for understanding and treating depression in older adults. They also strive, with great success, to make that framework come alive through the provision of multiple, detailed case examples.
The major contribution of the assessment section of this book is the presentation of a guide for conducting clinically sensitive diagnostic interviews with older adults and their families. This section provides a brief but clinically astute presentation of both general principles and specific examples for conducting effective interviews. It would be helpful to the individual practitioner and to those in training roles.
The authors also cover general principles to guide treatment decisions with older adults. Much of this is exemplary in providing guidance that is reasonable given current knowledge. But there is much we don't know! For example, the authors state, "in cases of moderate to severe depression, a combination of medication and psychotherapy has been shown to have the best outcomes" (p. 45). This is a common recommendation—but the research unfortunately is not so clear. As another example, the authors state that practitioners should "treat depression as a chronic, recurring illness" (p. 46). This is another controversial area where the research is far from compelling. (Each of these controversies recurs in the other two volumes reviewed in this essay and will be explored, below, as cross-cutting issues.) And the authors ultimately can offer no guidance as to which psychological treatment approaches might be most effective with different patients, because the data base to draw on for making such recommendations is unavailable. The authors explore this issue in a clinically sensitive way in the case examples that make up the bulk of the volume. These are rich, complex cases that seem much more true-to-life than the average textbook example. The patients are of notably diverse backgrounds, including different minority groups, socioeconomic status, and marital status (a nice addition would have been diversity in sexual orientation). The development of depression is explored in each case. The approaches to treatment are clearly delineated and include use of medication and various empirically supported psychotherapies. The outcome is presented for each case (and just as in real life, the outcomes are not always perfect). The richness of the clinical material highlights the lack of research to guide many of the decisions that clinicians still must make in conceptualizing cases and in deciding which of the evidence-based approaches to psychotherapy might be most helpful to each particular client.
Dan Blazer, the author of the second volume, has made important contributions for decades to our understanding of geriatric depression. His volume, Depression in Late Life (3rd ed.), is an updated version of his classic. In this updating the epidemiology of late life depression receives particular attention, and this is invaluable material. Blazer was one of the first to help the field challenge the assumption that older adults have especially high rates of clinical depression. He provides in this volume a wonderful overview of the current understanding of prevalence and incidence of depression in all its varieties, from adjustment disorder with depressed mood to major depression. Even more valuably, he provides a scholarly but clear and engaging overview of principles of epidemiological research, and he explores how data on the epidemiology of geriatric depression are influenced by methodological considerations. This should be "must" reading for everyone interested in late life depression.
In the third edition, the chapters addressing psychiatric intervention are updated especially well. Material on antidepressant medications and electroconvulsive therapy (ECT) are particularly up-to-date and thorough. Some other chapters do not appear to be updated with similar attention. For example, the chapter on psychological approaches has no references after 1990 and no mention of a variety of important research and clinical approaches. For those seeking medical information from a psychiatric perspective, this volume will be indispensable. However, the other two volumes reviewed in this essay seem to be more thorough and to better represent a contemporary psychological approach.
Chapter 3 of the Blazer volume, on the "Natural History" of depression, presents useful information about differences in depression between those who experience a first episode later in life and those who are aging with recurrent episodes of depression. This chapter also reviews research on chronicity of depression and summarizes studies up to 1991 that followed either community samples (of individuals not necessarily seeking treatment) or studies of medication treatment with long-term follow up. Based on these studies, Blazer argues for the "rule of thirds": one third will recover and not experience recurrence of depression, one third will recover but experience recurrence, and one third will not recover satisfactorily from the initial episode. His review of the literature that he has included is exemplary, but the omission of more recent studies and of research on long-term outcomes with psychological treatment, particularly cognitive-behavioral therapy, is a limitation that I will explore further in a discussion of cross-cutting issues.
Physical Illness and Depression in Older Adults: A Handbook of Theory, Research, and Practice, by Gail M. Williamson, David R. Shaffer, and Patricia A. Parmelee, offers an interprofessional approach to understanding a particular aspect of depression in older adults—specifically its relation to physical health and function. This book is essential reading, and possibly the strongest overall book extant on late life depression.
The opening chapter provides a scholarly and engaging overview of how depression and disability can be mutual risk factors for each other and what methodological approaches can best be used to examine these complex relationships. This overview is followed by a series of chapters exploring research on specific aspects of these relationships. Among the standout chapters is the excellent review by Jeffrey Lyness and Eric Caine of methodology needed to establish that a medical illness creates depression through pathophysiological mechanisms. This is often the default assumption when depression is associated with a medical condition, but there are many other possible explanations for such an association, and it is important not to assume that the depression is a manifestation of the disease process.
Other chapters explore some of these possible alternatives: the relationship to disability and its negative impact on activity and everyday life, the impact of pain, the impact of illness on family function, and the impact of "affective suffering" are all explored as crucial dimensions that may mediate the relationship between physical illness and depression. Barry Gurland, Sidney Katz, and Zachary Pine offer a model of longitudinal research to tease apart the complex interrelationships among disease, suffering, and depression. The summary chapter in this volume, by L. Stephen Miller, is right on target:
The relation between physical illness and the development of depression in older adults is affected (most likely mediated) by additional factors. It is crucial to identify and understand this relation and these additional factors if we expect continued progress in the advancement of our theoretical, research, and practical knowledge of physical illness and depression in older adults. Furthermore, the unique role of functional ability in both depression and physical illness appears as a particularly important factor in understanding this complex relationship. (pp. 333–334).
Despite its tremendous strength and general grounding in research, this volume, too, is controversial when it turns to treatment. In an overview chapter by Herbert Schulberg, Richard Schulz, Mark Miller, and Bruce Rollman, the statement is again offered (as in Karel and colleagues) that combined medication and psychotherapy is the treatment of choice. Only one study, utilizing only one type of psychotherapy and one medication, is offered as evidence for that argument. This is a topic in great need of careful exploration.
Cross-Cutting Issues
These three volumes, taken together, provide a window on our current knowledge, but also help point out those situations when we currently must go beyond well-established knowledge in trying to provide clinical services to older adults. It is appropriate to go beyond current evidence in such situations, but I will argue that it is equally important to be clear when we are doing so. When we face directly the limitations of the evidence base that we can draw on clinically, we can recognize and emphasize the need for research to focus particularly on those areas that are the clinical equivalent of wilderness on the map.
Two such issue areas stood out for me in reviewing these books. I will explore each of these as a call for future research: (a) the need to clarify the optimal treatments and combinations of treatments for depressed older adults, both generally and as a function of presenting features of the depressive episode; and (b) the need to clarify the expected chronicity of depression and how chronicity is affected by treatments of various kinds.
Each issue area shares two common features. First, the questions they raise can only be addressed usefully by longitudinal research. This is preaching to the choir. Gerontologists and geriatricians have been in the forefront in arguing for the importance of longitudinal research, rather than drawing conclusions based on cross-sectional studies. Longitudinal research has always been the touchstone for the study of aging, but there are many pressures that make it difficult to fund and conduct, especially for relatively junior researchers seeking to establish academic careers. It is crucial for all of us who study older adults to continue emphasizing the need for contingencies that will ensure the dominance of such longitudinal work as our methodological foundation. Second, each issue area is best addressed through interprofessional collaboration. It is important for psychologists, psychiatrists, primary care geriatricians, nurses, social workers, and the full range of health care providers to collaborate in designing and conducting research, reading each other's literatures, and discussing how findings from various perspectives can be integrated to provide a holistic picture of issues in late life depression. The Williamson, Shaffer, and Parmalee volume is a compelling object lesson in the power of such collaboration to enrich our understanding of complex phenomena.
Combined Medications and Psychotherapy—What Do We Really Know?
Two of the three volumes reviewed (Karel and colleagues and Williamson and colleagues) recommend combined medication and psychotherapy as the treatment approach of choice for late life depression. However, as noted above, little evidence is provided in these books to support this contention. The evidence base in late life with regard to this issue is extremely limited. The study most cited as supporting combination therapy (Reynolds et al., 1999) included only individuals older than 70 years of age who had recurrent depressive episodes prior to entry into the study of combination therapy (interpersonal psychotherapy and nortriptyline). Niederehe (1996) has argued previously that the database to support combination therapy as an ideal is insufficient, although he also has argued that such therapy is a reasonable clinical practice.
In studies with mid-life adults, the issue also remains unresolved. There are studies that show combination therapy to be most effective, studies that show worse outcomes from combining mediations, and studies that show either approach to be as effective as the combination. The discrepancies have not yet been elaborated in a way that allows a theoretical understanding of how to tell which combination, for which patients, may be important. However, some interesting and relevant studies are worth considering.
First, considering just the relative efficacy of medication versus psychotherapy, Zeiss and Breckenridge (1997) compared a meta-analysis of psychotherapy outcome studies for treatment of depression in older adults (Scogin & McElreath, 1994) to a meta-analysis of medication studies with older adults (Schneider, 1994). This comparison demonstrated that effect sizes for psychotherapy were at least as good as effect sizes for medication studies. In addition, DeRubeis, Gelfand, Tang, and Simons (1999) have shown, in a meta-analytic review of all relevant literature, that depression in mid-life adults is equally well-treated by medications or one of the empirically supported psychotherapies. Further, they found that severity of the depression was not a predictor of which treatment approach would be most efficacious. Because this challenges one of the findings of the early National Institute of Mental Health (NIMH) collaborative study of depression treatment, and the psychiatric treatment guidelines that were based on that collaborative study, the findings of DeRubeis and colleagues have been slow to be absorbed into clinical wisdom. Nonetheless, DeRubeis's study was a milestone and no effective counter-arguments to the findings have been presented.
These studies, of course, do not directly address the issue of whether combination treatment might be more effective. Recently, data have been presented by Keller and colleagues (2000) and by Arnow and Manber (2002) indicating that combination therapy may be superior when depression is chronic. They included only patients who had depressive episodes that had lasted over two years at entry into the treatment trial, or who had a major depressive episode superimposed on a long-term history of dysthymia, or who had a recurrent major depressive episode with incomplete inter-episode recovery with a total duration over two years. Patients aged 18 to 75 were included, although the mean age was only 43. In this study, patients were randomized to nefazodone, an intensive cognitive-behavioral therapy (CBT) variant, or combination therapy. In the acute phase response, combination therapy was significantly more effective than either intervention alone.
Although this is not an exhaustive review, it highlights some of the currently interesting, finer-grained issues regarding treatment efficacy and suggests the possibility that it may be useful and possible to develop a more refined decision matrix for the use of combination therapy. Recommending it for all older adults who are depressed may be unnecessary, and there may be unintended consequences. Offering combination therapy when a single approach would have been effective leads to additional unnecessary health care costs. In addition, many older adults are already on numerous medications, and all medications have some potentially problematic side effects. Conversely, certain psychotherapy approaches have been shown to be effective in many studies, but not all patients will have access to one of those therapies, and they may be offered potentially unhelpful psychotherapy approaches if combination therapy is mandated. And there may be many patients who could not afford the combination of therapies and may receive no treatment at all if their health care system insists on a combination. Thus, for many—perhaps most—patients the combination of medication and psychotherapy may be no more effective than a single therapy approach, while adding costs and complications. However, there certainly may be many older patients, like those in the generally younger sample reported by Arnow and Manber (2002), who would derive significant additional benefit from combination therapy. It seems clear that future research needs to focus not just on trials comparing single intervention with combination therapy, but also on identifying predictive factors that identify patients who are most likely to derive optimal results from combination therapy, as compared to which patients will respond optimally to a single approach.
Chronicity and Relapse: Potential Unintended Consequences of Defining Depression as Chronic
Two of the volumes (by Karel and colleagues and Blazer) also argue that depression is best understood as a recurrent, chronic illness. Accordingly, they advocate that clinicians who treat depression should routinely be guided by the assumption that it will have a chronic course. It is certainly true that some people who have fully remitted from depression have relapses, and that more of those who do not fully remit have relapses. Both groups are more likely to experience a new episode of depression than someone who has never been depressed. But the relapse rates are not nearly as overwhelming as these volumes imply. For example, Lewinsohn, Zeiss, and Duncan (1989) used data from a large community-based sample of older adults to examine recurrence of depression for 1,130 individuals who had a first episode. Of those, 45% (513) reported a second episode (over a 10-year follow-up period) and only 15% reported a third episode. Summarizing data from studies in the United States (across the adult life span, not just in older adults), Mueller and Leon (1996) concluded that most people who develop major depression recover from their initial episode and that a minority develop additional episodes. Even the data presented in the Blazer volume suggest that, if treatment is successful in generating full remission, fewer than one half of the patients treated will incur a new episode.
Further, again examining evidence from the study of treatment of depression in mid-life, it seems clear that the modality of treatment utilized has major impact on the likelihood of chronicity. This is shown perhaps most clearly in data reported by Hollon and Dimidjian (2002) from a study of patients meeting criteria for severe depression (similar findings are summarized in Hollon et al., 2002). As in research reviewed above, in well-controlled trials, CBT was as effective as medication in terms of symptom improvement and number of patients reaching full remission. In addition, there was a strongly significant difference in rates of relapse; patients who received CBT had from 10% to 20% relapse over a lengthy follow-up period, unlike patients who had received medication, who had from 50% to 80% relapse rate. Arnow and Manber (2002) have reported similar data, in which the probability of recurrence of depression was much higher for patients who improved on nefazodone (30%) than for patients who improved with CBT (10%). Thus, the "rule of thirds" offered by Blazer seems to apply particularly to patients who received only medication treatment, at least in studies of mid-life depression. Patients who receive CBT have a much lower likelihood of recurrence of depression (and this is possibly true of other empirically supported therapies such as interpersonal therapy, although this has not yet been demonstrated).
The directive to treat everyone as if depression could recur can seem attractive. Since we don't really know the risk factors for relapse, a conservative approach is to treat everyone as if they could relapse, and seek to prevent it, even though only a minority (albeit a sizable one, at least in some studies) will relapse. However, well-intended actions can have unexpected consequences. A specific concern in this case is unintended effects that may result from telling everyone who is treated for depression that they have a chronic condition. In fact, such action might serve to increase the overall rate of relapse, as people interpret the normal ups and downs of everyday life as signs that their depression is returning, and generate a depressive downward spiral as a result of the worry and despair this causes. Ultimately, the decisions regarding when and with whom to expect a chronic course of depression is not well-informed by current research except that, as described above, patients who receive an active psychotherapy such as CBT have a fairly low probability of recurrence. But even within CBT responders, we have little or no information about what risk factors predict which of them will relapse. As noted above, an interprofessional approach to longitudinal research on this issue should be a high priority and could serve to improve our ability to provide the best, yet least necessary, care for older adults who have experienced depression.
Areas for Future Research
In summary, I have attempted to put the rich information offered by the three volumes reviewed in this essay into a context in which they also can be seen as offering a valuable guide regarding the gaps in our knowledge. In that spirit, I have offered four primary recommendations for future research to close those gaps, or at least to reduce them:
References
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