Psychometric tests used for the early detection of dementia often are seen as too difficult or too complex. Classical neuropsychologic tests were not developed for this purpose. Sensitivity and specificity to discriminate "healthy" vs. "ill" are low. For measuring both dementive and depressive symptoms, so far no test has been published. The objective of this study was to develop a sensitive and specific test for dementia that is easy to administer and to evaluate. Moreover, it should discriminate dementia from depressive pseudodementia. With respect to former studies, items were selected that recognized patients in the beginning of the disease. Additionally, depressive symptoms were rated. With the items for dementia, 88 patients with dementia of the Alzheimer type, 52 patients with depressive disorder and 37 healthy elderly controls were investigated. In this group of already diagnosed patients, the test reached a sensitivity and specificity of 100 percent (healthy elderly controls vs. patients with Alzheimer's disease: n = 125, U = 0, p < 0.001; patients with depressive disorder vs. patients with Alzheimer's disease: n = 140, U = 0, p < 0.001; healthy elderly controls vs. patients with depressive disorder: n = 89, U = 485.5, p < 0.001). For the dementia items, the inter-rater-reliability was rs = 0.996 (p < 0.001, n = 18), for the depression items it was rs = 0.753 (n = 18, p < 0.001). The test-retest-reliability was rs = 0.868 (p < 0.001, n = 35) for the dementia items and rs = 0.7 (n = 8, p < 0.05) for the depression items. These validation data will make the test useful for practitioners. Its ability to discriminate patients suffering from dementia of the Alzheimer type from healthy controls is comparable to tests consuming more time.

Neuropsychol Rev. 1998 Sep;8(3):109-67.
Differential diagnosis of the major progressive dementias and depression in middle and late adulthood: a summary of the literature of the early 1990s.
Rosenstein LD.
Department of Psychiatry, Scott & White Clinic and Memorial Hospital, Temple, Texas 76508, USA.

There is a preponderance of research on the neuropsychology of the various dementias. There are also direct comparisons between two or more dementias available in the literature. This paper sought to summarize the most recent literature, primarily from 1990 through mid-1996, including recent reviews of the literature from previous decades. The purpose was to provide, in one location, a summary of neuropsychological (i.e., cognitive, motor, and psychiatric) characteristics of major noninfectious, progressive dementias and depression of middle and late adulthood. It is hoped that this review, particularly a summary table provided, will serve as a guide in the differential diagnosis of the dementias by clinicians. In addition to Alzheimer's disease, vascular dementias, Parkinson's disease, Lewy body dementia, Huntington's disease, and frontal lobe dementia, the impact of depression on cognitive functioning is covered given the frequency with which neuropsychologists are asked to differentiate depression from primary dementia.

Ateneo Parmense Acta Biomed. 1979;50(4):209-19.
Problems in differential diagnosis between early presenile dementia and depression in elderly persons
de Risio C, Mazzucchi A.

The difficulties in correct differential diagnosis between depression and early pre-senile dementia syndromes are pointed-out by the AA. They underline that, on the ground of literature reports and clinical experience, the instrumental methods (electroencephalography, cerebral blood flow examination, pneumoencephalography, evoked cerebral responses, etc...) appear of little use in differential diagnosis, if separately considered. A particular attention is called on psychometric tests, in order to worn the non-specialist against any too over-simplified and mechanistic acceptance of test results.

Dement Geriatr Cogn Disord. 2004 [Epub ahead of print]. Epub 2003 Oct 15.
Diagnosis and Treatment of Depression in Alzheimer's Disease. A Practical Update for the Clinician.
Lyketsos CG, Lee HB.
Division of Geriatric Psychiatry and Neuropsychiatry, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Md., USA.

Over 80% of patients with Alzheimer's disease (AD) develop 'noncognitive' neuropsychiatric symptoms at some point during the course of their illness. Depression is among the most frequent of such comorbidities. Affecting up to 50% of AD patients, depression is associated with severe negative consequences for patients and caregivers. Despite having a presentation in the context of AD that differs from typical 'geriatric' depression, it can be detected and quantified reliably, and can be differentiated from the other neuropsychiatric symptoms of AD. Several effective treatment modalities for depression in AD are available. In many cases, these reduce its adverse impact on patients and caregivers. This paper provides an overview of current knowledge regarding depression in AD for the clinician. It is followed by a practical discussion of the detection, evaluation, quantification, differential diagnosis and treatment of depression in AD.

J Geriatr Psychiatry Neurol. 2002 Fall;15(3):147-55.
Complexity in late-life depression: impact of confounding factors on diagnosis, treatment, and outcomes.
Kales HC, Valenstein M.
Department of Psychiatry, University of Michigan, Ann Arbor Veterans Affairs Medical Center 48105, USA.

Late-life depression is a heterogeneous syndrome. Although depression in elderly patients is highly treatable, a number of factors or confounds create complexity in its overall management. Patient factors, such as medical illness, neuropsychiatric comorbidity, and race, may interact with provider factors to make management more complex. Outcomes and services research indicate that these factors, particularly medical illness, affect whether late-life depression is appropriately detected, diagnosed, and treated. Attention to such factors must be included in an agenda for mental health services research, with emphasis on the delivery of effective treatment to elderly patients with depression and improved outcomes in clinical settings.