Impairment in executive cognition (EC) is now recognized as relatively common among older persons with mild cognitive impairment (MCI), and may be predictive of the development of dementia. However, both MCI and executive functioning are broad and heterogeneous constructs. The present study sought to determine whether impairments in specific domains of EC are associated with specific subtypes of MCI. 124 MCI patients were divided into four subgroups (amnestic versus nonamnestic, and single-versus multiple-domain) based on their performance of widely-used neuropsychological screening tests. These patients and 68 normal elderly were administered 18 clinical and experimental tests of executive function. Principal components analysis suggested two highly reliable EC components, planning/problem-solving and working memory, and a less reliable third component, judgment. Planning/problem-solving and working memory, but not judgment, were impaired among the MCI patients. This was true even among those with Apure amnestic@ MCI, the least impaired group overall. Multiple-domain MCI patients had more severe impairments in planning/problem-solving and working memory than single-domain patients, leading to the supposition that they, not pure amnestic MCIs, are at highest risk of imminent dementia. Keywords executive function; mild cognitive impairment; dementia; principal components analysis; flexibility; working memory; planningThe status of mild cognitive impairment (MCI) as an important clinical entity remains debated. Expert opinion ranges from it being early Alzheimer=s disease (AD) in virtually all cases (Morris et al., 2001) to it being a diagnostic nonentity (Milwain, 2000;Gauthier & Touchon, 2005; Whitehouse, 2007). Most opinions fall somewhere between these two extremes, and view MCI as a heterogeneous cognitive state that sometimes heralds the onset of progressive Address correspondence to: Jason Brandt, Ph.D., Department of Psychiatry and Behavioral Sciences, The Johns Hopkins Hospital, 600 N. Wolfe Street, Meyer 218, Baltimore, MD 21287-7218, phone 410-825-9048, fax 410-955-0504, jbrandt@jhmi.edu. Publisher's Disclaimer: The following manuscript is the final accepted manuscript. It has not been subjected to the final copyediting, fact-checking, and proofreading required for formal publication. It is not the definitive, publisher-authenticated version. The American Psychological Association and its Council of Editors disclaim any responsibility or liabilities for errors or omissions of this manuscript version, any version derived from this manuscript by NIH, or other third parties. The published version is available at www.apa.org/journals/neu. NIH Public Access Author ManuscriptNeuropsychology. Author manuscript; available in PMC 2010 September 1. Published in final edited form as:Neuropsychology. Chertkow et al., 2007). Much recent research has focused on determining the characteristics of patients with MCI that predict the progression to AD or another dementia.It is now widely recognized that several ...

Cognitive impairment in late life depression is prevalent, disabling, and heterogeneous. Although mild cognitive impairment in depression does not usually progress to dementia, accurate assessment of cognition is vital to prognosis and treatment planning. For example, executive dysfunction often accompanies late-life depression, influences performance across cognitive domains, and is associated with poor antidepressant treatment outcomes. Here, we review how assessment can capture dysfunction across cognitive domains, and discuss cognitive trajectories frequently observed in late-life depression in the context of the neurobiology of this disorder. Furthermore we review the efficacy of a sample of interventions tailored to specific cognitive profiles.

Patients with amnestic mild cognitive impairment (aMCI) have been described as exhibiting greater impairment on tests of category fluency than letter fluency. This has been offered as evidence that this condition represents pre-clinical Alzheimer’s disease (AD). We hypothesized that this pattern of differential impairment is dependent on the specific semantic categories and initial letters selected, and is not specific to AD and aMCI. A total of 40 cognitively normal older adults, 74 MCI patients—25 “amnestic single domain” (aMCI), 27 “amnestic multiple domain”, and 22 non-amnestic—and 29 AD patients were tested with multiple forms of semantic-category and initial-letter fluency tasks. The pattern of deficits within and across groups was highly dependent on the specific categories and letters chosen. Overall, aMCI patients did not demonstrate greater impairment in category than letter fluency. In fact, the level and pattern of their performance resembled that of cognitively normal older adults much more than AD patients. MCI patients with deficits in multiple cognitive domains performed most like AD patients. These findings indicate that verbal fluency performance is highly influenced by the specific tasks used, and impairment on semantic fluency is not characteristic of pure amnestic MCI.