Treatment for Depression in Older Persons with Dementia

To the Editor:

I read with interest the review article by Gellis et al¹ about treatment for depression in older persons with dementia. I would like to contribute to the discussion by highlighting three salient observations.

First, depressive features in dementia are often subsyndromal and not severe enough to meet the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM- IV) criteria for major depressive disorder (MDD).^2,3 Some authors propose a distinct set of criteria for depression of Alzheimer’s disease (dAD), which is increasingly recognized as a distinct entity from MDD.² In particular, dAD may be less severe, less persistent with a waxing and waning course, less correlated with psychosocial factors, and exhibit fewer melancholic factors. In contrast to the DSM IV criteria for MDD, the more inclusive dAD criteria require the presence of fewer symptoms (3 instead of 5); do not require the presence of symptoms nearly every day; incorporate irritability, social isolation, and hopelessness as part of the criteria; and revise criteria for anhedonia to reflect decreased positive affect or pleasure in response to social contact and usual activities. Data from population-based cohorts such as the Cache County Study support the use of less restrictive criteria for the determination of depression in dementia.⁴

Second, just as many guidelines stress the importance of routinely assessing for suicidal risk in any older person who is newly diagnosed with depression, a similar degree of vigilance cannot be overemphasized in the evaluation of depression in dementia.⁵ Consistent case reports of completed suicides in older persons with dementia highlight the folly of the previously held assumption that the level of risk for suicide in persons with dementia is negliglible. Careful scrutiny of the literature readily reveals a high-risk phenotype predisposing to increased suicidal risk: male gender, highly educated professional, preserved insight, depressive symptoms that need not necessarily meet criteria for major depression and often postdate the onset of cognitive symptoms, and suicidal ideation.⁶

Last, I would like to draw attention to a recent excellent review of the differential behavioral effects of antidementia drugs, namely cholinesterase inhibitors (ChEIs) and memantine.⁷ Mood symptoms and apathy were the behavioral domains that most commonly responded to ChEIs, whereas memantine was associated with a reduction in irritability and agitation. However, the authors noted that many of these studies were not designed to test the psychotropic properties of antidementia drugs, and there is substantial variability among trials in terms of behavioral outcomes.

Dr. Wee-Shiong Lim, MBBS, MRCP (UK)
Consultant, Department of Geriatric Medicine
Tan Tock Seng Hospital
Singapore

References

1. Gellis ZD, McClive-Reed KP, Brown EL. Treatments for depression in older persons with dementia. Annals of Long-Term Care: Clinical Care and Aging 2009;17(2):29-36.
2. Olin JT, Schneider LS, Katz IR, et al. Provisional criteria for depression of Alzheimer’s disease. Am J Geriatr Psychiatry 2002;10:125-128.
3. Olin JT, Katz IR, Meyers BS, et al. Provisional diagnostic criteria for depression of Alzheimer’s disease. Rationale and background. Am J Geriatr Psychiatry 2002;10:129-141.
4. Lyketsos CG, Steinberg M, Tschanz JT, et al. Mental and behavioural disturbances in dementia: Findings from the Cache County Study on Memory in Aging. Am J Geriatr Psychiatry 2000;57:708-714.
5. Lapid MI, Rummans TA. Evaluation and management of geriatric depression in primary care. Mayo Clin Proc 2003;78:1423-1429.
6. Lim WS, Rubin EH, Coats M, et al. Early-suicide Alzheimer Disease represents increased suicidal risk in relation to later stages. Alzheimer Dis Assoc Disord 2005;19:214-219.
7. Cummings JL, Mackell J, Kaufer D. Behavioural effects of current Alzheimer’s disease treatments: A descriptive review. Alzheimer’s & Dementia 2008;4:49-60.

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Response from Drs. Gellis, McClive-Reed, and Brown:

We appreciate the discussion comments from Dr. Mei based on our recent article.¹ The subsyndromal nature of depressive symptoms in this population, even when not sufficiently severe to meet DSM-IV criteria for major depressive disorder, is clearly significant to the patient and the clinician attempting to assess the symptoms being observed. Perhaps dAD may be considered as a relevant risk indicator for MDD if regarded as a component of an early phase of MDD in patients with dementia. However, not all patients with dAD will develop more severe symptoms that can lead to a diagnosis of MDD. An alternative way to view dAD is as a subthreshold disorder similar to a diagnosis of minor depression (or one with even fewer symptom markers) in older adults without dementia. Currently, in the population of older adults with dementia, occurrence of clusters of clinically meaningful depressive symptoms that do not meet criteria for MMD is a distinctive feature that may be overlooked. Moreover, the notion of types of symptoms may be salient for this discussion. For instance, we consider whether loneliness may be a relevant depressive feature in the patient with dementia even though it may not always be observed or measured. Loneliness as a condition may be viewed as a self-imposed withdrawal from day-to-day life, or it may be regarded as a symptom of dementia due to physiological personality change.²

We agree that assessment of suicide risk in persons with comorbid dementia and depression needs attention. In addition, a thorough evaluation of suicidality, in such cases, should consider common, potentially life-threatening behaviors not always viewed as suicidal, such as compliance with or refusal of medication and treatment.

The provisional diagnostic criteria for depression in persons with Alzheimer’s disease proposed by a panel of experts is of importance, and we look forward to seeing further validation studies of these new depression criteria. Detection and accurate assessment of depression of persons with Alzheimer’s disease and other dementia disorders is an essential step toward improved treatment and management. A common barrier to depression detection efforts in the long-term care setting that has received little attention is the lack of a knowledgeable informant, which is crucial for patients with moderate to severe dementia.³ Often, in the nursing home setting, the certified nursing assistant provides the most direct personal care and spends the most time with residents, but frequently lacks the training to observe for behaviors indicative of depression.

Zvi D. Gellis, PhD
School of Public Policy & Practice
University of Pennsylvania, Center for Mental Health & Aging
Philadelphia

Kimberly P. McClive-Reed, PhD
Institute of Gerontology, School of Social Welfare
State University of New York at Albany

Ellen L. Brown, EdD, MS, ARNP
College of Nursing and Health Sciences
Florida International University
Miami

References

1. Gellis ZD, McClive-Reed KP, Brown EL. Treatments for depression in older persons with dementia. Annals of Long-Term Care: Clinical Care and Aging 2009;17(2):29-36.
2. Barg FK, Huss-Ashmore R, Wittink M, et al. A mixed methods approach to understanding loneliness and depression in older adults. J Gerontol Soc Sci 2006;61B:S329-S339.
3. Alexopoulos GS, Abrams RC, Young RC, Shamoian CA. Cornell Scale for Depression in Dementia. Biol Psychiatry 1988;23:271-284.