Journal of Geriatric Psychiatry and Neurology

Dementia and depression are frequently comorbid among older adult patients. Depression is related to cognitive decrement and can even represent the first signs of a neurodegenerative process. It can be difficult to distinguish depressed patients exhibiting the first signs of dementia from those whose cognition will improve with treatment. In this article, studies from the neuropsychological literature are reviewed that aid in accurate diagnosis and prognosis. Furthermore, the relationship between depression and dementia is explored by examining potential neurobiological mechanisms that may potentiate both syndromes in the context of the ongoing debate on depression as a prodrome and/or a risk factor for dementia. This article is concluded with suggestions for clinicians when deciding who to refer for neuropsychological assessment and with ideas for further research that might promote a better understanding of the complex association between depression and dementia during old age. (J Geriatr Psychiatry Neurol 2007;20:189-198)

Psychotropic medications are widely used in older adults and may cause neurocognitive deficits. Older adults are at increased risk of developing adverse effects because of age-related pharmacodynamic and pharmacokinetic changes. This article provides a comprehensive review of the undesirable, and at times beneficial, effects of psychotropic medications. The review covers a wide range of medications that impair executive function, memory, and attention, as well as a much smaller group of medications that lead to improved neurocognitive function. Some of the most commonly used psychotropic medications in older adults, namely, antidepressants, sedatives, and hypnotics, are among the drugs that most consistently lead to cognitive impairments. Medications with anticholinergic properties almost invariably lead to neurocognitive dysfunction, despite symptom improvement. The neurocognitive costs and benefits of psychiatric medications should be considered in the context of disease treatment in older adults. (J Geriatr Psychiatry Neurol 2007;20:199—214)

This review begins with a historical accounting of the evolution of the concept of mild cognitive dysfunction, including nomenclature and criteria from Kral to Petersen. A critical analysis of the main elements relating to assessment and diagnosis of mild cognitive dysfunction is provided. Methodological limitations in design, measurement, and characterization, especially as they relate to older African Americans, are identified. Data from a 15-year longitudinal study of community-dwelling African Americans in Indianapolis, Indiana, indicate a 23% prevalence of all-cause mild cognitive dysfunction, with approximately 25% progressing to dementia in 2 years and another 25% reverting to normal cognition in the same interval. Factors contributing to this longitudinal variability in outcomes are reviewed, including the role of medical health factors. The review closes with suggestions for next steps in the epidemiological research of mild cognitive impairment. (J Geriatr Psychiatry Neurol 2007;20:215—226)

The neurocognitive and behavioral profiles of vascular dementia and vascular cognitive impairment, dementia with Lewy bodies and Parkinson's disease with dementia, and dementia syndromes associated with frontotemporal lobar degenerations are compared and contrasted with Alzheimer's dementia (AD). Vascular dementia/vascular cognitive impairment is characterized by better verbal memory performance, worse quantitative executive functioning, and prominent depressed mood. Dementia with Lewy bodies and Parkinson's disease with dementia are equally contrasted with AD by defective processing of visual information, better performance on executively supported verbal learning tasks, greater attentional variability, poorer qualitative executive functioning, and the presence of mood-congruent visual hallucinations. The frontal variant of frontotemporal lobar degeneration (frontotemporal dementia) differs from AD by better multimodal retention on learning tasks, different patterns of generative word fluency, defective qualitative executive functioning, and by markedly impairment of comportment. For temporal variants of frontotemporal lobar degenerations, progressive aphasia and semantic dementia, worse language performance relative to AD is typically characteristic. (J Geriatr Psychiatry Neurol 2007;20:227-238)

There have been increasing efforts to develop cognitive interventions to ameliorate cognitive problems experienced by older adults. In healthy elderly populations, cognitive training has centered on the enhancement of memory and speed of processing, with the goal of maximizing current function and reducing the risk of cognitive decline. Among elderly persons with nonprogressive neurological conditions such as traumatic brain injury (TBI) and stroke, there has been an emphasis on rehabilitation to help restore function. Most recently, there has been increased attention on the development of new cognitive techniques to treat persons with progressive neurodegenerative conditions such as Alzheimer disease. The literature is reviewed on current approaches to cognitive interventions in elderly healthy populations, and a particular emphasis is placed on the most recent strides in progressive neurocognitive conditions, particularly Alzheimer disease. Important issues such as study design, the use of ecologically and functionally valid outcome measures, the need to examine heterogeneous populations and cross-cultural variables, and the incorporation of technologically based systems are examined. It is concluded that cognitive interventions in the elderly show considerable promise and deserve further study. (J Geriatr Psychiatry Neurol 2007;20:239—249)