Diagnostic Issues in Dementia: Advancing the Research Agenda for DSM-V

Can you imagine a more onerous job than trying to revise the Diagnostic and Statistical Manual of Mental Disorders ? But DSM-IV is getting old. Whether or not you agree with the categories that are being emphasized by the revision planners, you have to admire the effort.

Diagnostic Issues in Dementia follows a collection of white papers, Advancing the Research Agenda for DSM-V, in the slated progress toward the creation of DSM-V . David Kupfer is chair of the DSM-V Task Force, and Darrel Regier is the vice-chair. This gargantuan, decade-long revision process involves an international collaboration between the American Psychiatric Association (APA), the World Health Organization, and the National Institutes of Health. In 2005, the Dementia Work Group, chaired by three of the editors of Diagnostic Issues in Dementia, invited a small, international panel to convene in Geneva, Switzerland. The papers from that conference were published in the Journal of Geriatric Psychiatry and Neurology and have been republished, most without apparent change, in the book reviewed here.

This book summarizes in very few pages—146 pages, including references—what leaders in the fields of geriatric psychiatry and dementia research see as pertinent information. As such, it represents a manageable overview of the field for students, geriatrics residents and fellows, academics preparing lectures, or those studying for board exams. Chapters cover normal and abnormal aging of the brain, epidemiology of dementia, diagnostic criteria for various dementias, mild cognitive impairment, neuropsychological testing and neuropsychiatric syndromes, biomarkers, neuroimaging, and genetics.

All of the chapters take care to describe a historical perspective about what is known and how disorders became classified, which I found to be valuable and intriguing. Gaps that need more investigation are also identified. For example, it is still not clear if the depression associated with dementia has the same biological basis as major depression in younger people. This distinction has important ramifications for treatment, especially because the few studies that have looked at antidepressant use in depression in dementia have been, in the aggregate, less than convincing about the benefits of pharmacologic treatment.

Brief summaries of the presentations from the Geneva conference can be found online at dsm5.org. The information, prepared by Michael First, does an excellent job collating the highlights of each presentation. Some material from the conference was left out of the book, which is unfortunate. For example, there was a discussion by John Saunders on substance use and cognition that does not receive its own chapter in the book. Breakout sessions at the conference made recommendations for possible changes to DSM-V ; however, this information does not appear in easily accessible form in the book. Ideas for changes are embedded in the text of each chapter, but there is no wrap-up or final summary. There is a one-page appendix of recommendations attached after the reference section for Chapter 3—"Diagnostic Criteria in Dementia"—but I found it by accident.

The problem that I, as a geriatrics psychiatrist, have with DSM-IV definitions in dementia is their lack of specificity and the need to rule out so many other, less likely, diagnoses before I can give a name to a patient's symptoms. Any dementia will, at some point, cause problems with speech, recognition, ability to carry out patterned tasks, or executive function. When I have a question about diagnosis in dementia, I don't reach for the DSM-IV-TR for clarity; I reach for my beloved copy of Dementia: A Clinical Approach ( 1 ) and then try to retrofit my diagnosis to the ICD/DSM codes. If patients have mild cognitive impairment or are clearly disabled by dementia but their memory has been thus far spared, DSM-IV is more of a hindrance than a help.

Based on the material presented in Diagnostic Issues in Dementia, DSM-V may improve in these areas. DSM-V may get rid of the concept that age 65 is an important diagnostic consideration in Alzheimer's disease. I may include mild cognitive impairment as a diagnostic category, broaden the scope of the vascular dementia criteria to include more than multi-infarct dementia, and recognize that loss of function, not simply memory impairment, is the hallmark of some early dementias. Neuropsychiatric syndromes in dementia—in particular, psychosis and agitation—do not have as much evidenced-based clarity but are receiving appropriate discussion. These ideas for DSM-V resonate with my clinical experience.

However, some of the discussion in this book made me very nervous—in particular, the chapters on neuroimaging and on biomarkers. The chapter on neuroimaging was actually fascinating, but I shudder at the cost of doing imaging on an ever-increasing geriatric population. It's great as a research tool; I just hope the imaging will be used to identify treatments and not to expand the roster of routine clinical procedures. Likewise, the idea of doing routine lumbar punctures for diagnosis is unpalatable because of the cost but even more so because of the implications for patient care. The idea that "the lumbar puncture procedure itself can be streamlined and improved to markedly reduce the threat of lumbar puncture headaches" seemed so out of line with reality in nonacademic, rural, or non-Western settings that I pray that cerebrospinal fluid findings will never be part of diagnostic criteria for Alzheimer's disease. Maybe this procedure is necessary for rare dementias when diagnosis can't wait, but certainly not for routine diagnosis. I was horrified that researchers involved in DSM discussion panels even mentioned brain biopsy in the context of future changes in risk assessment for dementia diagnosis.

And then there is the issue of the pharmaceutical industry influence in these discussions. It's all well and good that the APA limited participation in the DSM-V Task Force to those who have received less than $10,000 a year from pharmaceutical companies in the past few years, but what about all of the folks who have already advanced their careers by receiving industry grants and now serve on panels and editorial boards and grant review committees? Is that taken into account anywhere? How has that affected creativity in research? Of the 27 members of the APA DSM-V Task Force, only eight members had no industry relationships in the past 36 months to report. In the volume reviewed here, 11 of 21 authors reported conflicts of interest. I fear that it's no coincidence that the pharmaceutical industry has achieved treatments for middle to end stages of Alzheimer's disease and that research in dementia has clustered, for the most part, in the same clinical ballpark. As the first chapter of this book makes clear, plaques and tangles are hardly the end of the story for Alzheimer's disease. People with no known dementia or with non-Alzheimer's dementias have the pathophysiologic findings, and a fair number of patients with dementia have neither plaques nor tangles. Maybe it's time to expand our horizons.

A surprise in this book is that genetics "has only meager offerings for DSM-V … those who expect a gene test or genetic profile that defines Alzheimer's disease or another dementia will be sorely disappointed." The issue of apolipoprotein E as a risk factor is clearly reviewed. Even though apolipoprotein E testing is not advised as a clinical tool, it is being used in research to enrich the sample of patients who may develop cognitive problems. As Gary Small points out, "combining apolipoprotein E genetic data with other relevant biological information (neuroimaging in his case) has proved to be a useful strategy for early detection of subtle brain abnormalities."

As a final harangue, I worry about the DSM as it tries to incorporate so many ideas from so many sources. One hopes that form follows function, but what does that mean when the end product will be used by clinicians as well as by the general public, certain businesses, and those in research? My hope is that they don't create something that makes it easier for insurance companies to deny treatment for my patients. DSM-V should appear sometime in 2011.