Dementia is an acquired, persistent, and usually progressive impairment in multiple cognitive domains, usually including memory. There must also be a significant decline in function that is severe enough to interfere with work or social life. As the disorder progresses, individuals with dementia often fail to recognize family members, are unable to express themselves clearly and meaningfully, and often undergo dramatic personality changes. In the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), dementia has been relabeled Major Neurocognitive Disorder. Mild cognitive impairment has been relabeled Minor Neurocognitive Disorder. Because this newer terminology has not been widely disseminated through the clinical world, we will continue to use the names dementia and mild cognitive impairment throughout this chapter.
Dementia is a common disorder with a prevalence that doubles every 5 years after the age of 60 years, affecting up to 45% of those aged 85 years and older. Today, over 5 million Americans are living with Alzheimer disease (AD) and related dementias. By 2050, up to 16 million will have dementia. Dementia is the sixth leading cause of death in the United States. In 2014, the direct costs of caring for those with dementia totaled an estimated $214 billion, including $150 billion in costs to Medicare and Medicaid. By 2050, these costs could rise as high as $12 trillion. Nearly one in every five dollars of Medicare spending is spent on people with Alzheimer and related dementias. Two-thirds of the 5 million seniors with Alzheimer disease are women. Women in their 60s are twice as likely to develop Alzheimer disease over the rest of their lives as they are to develop breast cancer.
Despite the high prevalence of dementia, the diagnosis is often missed by clinicians, particularly in the early stages. The primary care practitioner can play an important role in diagnosing and treating dementia. An early diagnosis can offer the opportunity to involve patients in meaningful advance care planning while they are still able to express their preferences clearly. In addition, potentially treatable causes, though rare, are more likely to be partially or fully reversed if diagnosed early. Later in the disease, the practitioner can work with other team members to manage difficult behaviors, ensure that the patient is as comfortable and safe as possible, recognize when referral for specialist care is needed, educate caregivers about the condition, and support caregivers in coping with their situations to the best of their abilities.
Alzheimer disease is the most common form of dementia, accounting for about 60–70% of cases. The age of onset varies considerably, but most commonly symptoms arise after the age of 70 years. Incidence of the disease increases with age. Women may be at a slightly higher risk of developing the disorder than men. The rare patient with early onset of AD (before ...