Behavrl Neuroscience

Dementia and Cognitive Impairment: Epidemiology, Diagnosis, and Treatment

Julie Hugo, MD and Mary Ganguli, MD, MPH

Synopsis

Clinicians can diagnose the syndromes of dementia (major neurocognitive disorder) and mild

cognitive impairment (mild neurocognitive disorder) based on history, examination, and

appropriate objective assessments, using standard criteria such as DSM-5. They can then diagnose

the etiological subtypes of these syndromes using standard criteria for each of them. Brain

imaging and biomarkers are gaining ground for the differential diagnoses among the different

disorders. Treatments for the most part are still symptomatic.

Keywords

Neurocognitive disorder; Mild Cognitive Impairment (MCI); Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5); National Institute on Aging- Alzheimer’s Association (NIA-AA) Guidelines; diagnosis; risk factors; biomarkers; Alzheimer’s disease

INTRODUCTION

When older patients and their families report symptoms of “memory loss,” experienced

clinicians know that these concerns refer to a range of cognitive abilities or to general

cognitive decline, and not just memory. However, some degree of cognitive slowing is

typical of normal aging.

The clinician’s first challenge, therefore, is to identify the cognitive changes that are

clinically significant. Dementia is typically diagnosed when acquired cognitive impairment has become severe enough to compromise social and/or occupational functioning. Mild cognitive impairment (MCI) is a state intermediate between normal cognition and dementia, with essentially preserved functional abilities.

We will describe these entities and their diagnoses using the framework of the recently

published fifth edition of the American Psychiatric Association’s Diagnostic and Statistical

Manual (DSM-5) (Table 1).1 Briefly, the DSM-5 diagnosis of Major Neurocognitive

© 2014 Elsevier Inc. All rights reserved.

Corresponding Author: Mary Ganguli, MD, MPH, Professor of Psychiatry, Neurology, and Epidemiology, University of Pittsburgh, Pittsburgh, PA, WPIC, 3811 O’Hara Street, Pittsburgh, PA 15213, GanguliM@upmc.edu.

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NIH Public Access Author Manuscript Clin Geriatr Med. Author manuscript; available in PMC 2015 August 01.

Published in final edited form as: Clin Geriatr Med. 2014 August ; 30(3): 421–442. doi:10.1016/j.cger.2014.04.001.

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