In the United States alone, rates of Alzheimer's disease (AD) and other dementias are at epidemic proportions, afflicting approximately 5.4 million individuals, with 96% being older than 65. Of this older group, 63% are female (Alzheimer's Association, 2012). The main risk factor for all forms of dementia is age, and with the number of older Americans projected to nearly double in the next 30 years, there will clearly be a tremendous surge in the number of dementia cases, barring any major advance in prevention or treatment. It is estimated that AD and other dementias afflict over 35 million people worldwide currently, with a projected increase to over 155 million people by 2050 (Alzheimer's Disease International, 2010). Most of the increase will take place in developing Southeast Asian countries such as China and India. The annual cost of treating dementia in the United States was estimated to be between $157 billion and $215 billion in 2010, eclipsing the costs of both heart disease and cancer (Hurd et al., 2013).
Case Study
Mr. R was a retired businessman who had immigrated to the United States at the age of 10 years and had spent most of his early life working in the garment industry in New York City. He later worked as a furrier, running his own business for more than 20 years. He was married for more than 60 years and had two grown daughters. Mr. R sold his business at the age of 75, and he and his wife moved to a retirement community. His wife passed away when he was 85, and Mr. R insisted on living by himself, despite his daughtersâ concern that his memory and physical strength had declined. Shortly after his 90th birthday, Mr. R fell and broke his hip. After the hip surgery, he was admitted to a long-term care facility for two months of rehabilitation, followed by permanent placement in a nursing home. Staff reported that Mr. R had significant cognitive impairment and symptoms of depression. He frequently spoke about his deceased wife, stating that he wished to join her. Six months after admission, Mr. R developed pneumonia, leading to his hospitalization. On his return to the facility, the staff noted that he was confused, paranoid, and agitated. The acute confusion resolved after approximately two weeks, but Mr. R's cognitive abilities appeared to be much worse. He continued to be quite depressed and even overtly suicidal, with paranoid ideation and episodes of agitation. These symptoms improved slowly after Mr. R was placed in a unit for residents with behavioral problems and was treated with psychotropic medications. Over the next few years, Mr. R's short-term memory continued to worsen, and he could not remember important facts about his life. He also began to have difficulty recognizing familiar family and friends. With time, he became more apathetic, and his language function worsened to the point where he was nearly mute. He stopped walking and relied on nursing staff for all of his daily needs.
Many details of this caseâa slow, insidious course; comorbid medical problems that led to further decline; and associated psychiatric problems, including depression, psychosis, agitation, and deliriumâare typical for dementia, especially AD. As this case illustrates, long-term care placement is a frequent result, since many individuals progress to a near vegetative state in which they are completely dependent on others for care.
Definitions and Diagnostic Criteria
According to the diagnostic classification in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, or DSM-IV-TR (American Psychiatric Association, 2000), dementia refers to the development of multiple cognitive or intellectual deficits that involve memory impairment of new or previously learned information and one or more of the following disturbances:
- aphasia, or language disturbance;
- apraxia, or impairment in carrying out skilled motor activities despite intact motor function;
- agnosia, or deficits in recognizing familiar persons or objects despite intact sensory function;
- executive dysfunction, or impairments in planning, initiating, organizing, and abstract reasoning.
These deficits result in significant impairment in both social and occupational functioning, and they represent a decline, often with an insidious onset and progressive course, from a previous level of functioning.
As noted, the revised diagnostic nomenclature for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, or DSM-5 (American Psychiatric Association, 2013) replaces the term dementia with major or minor neurocognitive disorder (NCD) to provide a broader definition. Whereas the DSM-IV-TR criteria for dementia are patterned after AD, the DSM-5 criteria encompass a variety of potential forms of dementia (in addition to delirium and amnestic disorders) and do not require memory impairment in all cases. Individuals can meet the criteria for major NCD if they have decline in one (and typically two or more) of the following cognitive domains:
- complex attention
- executive ability
- learning and memory
- language
- perceptual-motor
- social cognition.
These domains are detailed in Table 1.1. According to DSM-5 criteria for major NCD, the declines in these domains are acquired and not developmental, represent a decline from previous levels of functioning (preferably established by neuropsychological testing), interfere with independence in everyday activities, and are not associated with the cognitive deficits seen in other major mental disorders such as schizophrenia or bipolar disorder (American Psychiatric Association, 2013). The criteria for minor NCD (labeled âCognitive Disorder, Not Otherwise Specifiedâ in DSM-IV-TR) are similar to those for major NCD, although the degree of cognitive impairment is less, and it does not interfere entirely with independence in everyday activities. The diagnosis of mild cognitive impairment (MCI) is considered a prodromal state of dementia; it is described in Chapter 3. In DSM-5 it would be labeled as a mild NCD due to a specified cause, such as âmild NCD due to AD.â
DSM-5 includes specifiers for severity (mild, moderate, and severe) and the presence (or absence) of behavioral disturbances, which may include psychosis, mood disturbances, agitation, apathy, and other unspecified behavioral symptoms.
Classification
Many different ways exist for classifying dementia subtypes, including classification by etiology, anatomic location, course, and prognosis. The main subtypes of NCD in DSM-5 include the following:
- NCD due to Alzheimer's disease
- vascular NCD
- NCD with Lewy bodies
- NCD due to Parkinson's disease
- frontotemporal NCD
- NCD due to traumatic brain injury
- NCD due to HIV infection
- substance-/medication-induced NCD
- NCD due to Huntington's disease
- NCD due to prion disease
- NCD due to another medical condition
- NCD due to multiple etiologies
- unspecified NCD
Each of these categories has its own specific criteria, which will be detailed in the corresponding chapters in this text. NCD due to another medical condition specifies that there is evidence from the history, physical examination, or laboratory findings that the NCD is the âpathophysiological consequenceâ of a specified medical condition distinct from the categories already stated (American Psychiatric Association, 2013). An unspecified NCD involves a condition in which the symptoms meet general NCD criteria...