Refers to a situation in which elderly people have been prescribed several medications. The various side effects and interactions of those medications can result in dementia symptoms.

Deposits of a particular kind of protein in the brain that interfere with communication between neurons; Lewy bodies cause neurocognitive disorder.

The idea that cognition should be measured in settings and conditions that are as realistic as possible and that the abilities measured should be those needed in real life.

Impairments of intellectual functioning caused by organic brain damage or disease. NCDs may be diagnosed as major or mild, depending on the severity of symptoms. They become more common with age, but they are abnormal and pathological even in the very old.

An examination of one’s own life and one’s role in the history of human life, engaged in by many elderly people.

Clumps of a protein called beta-amyloid, found in brain tissues surrounding the neurons; a normal brain contains some tau, but in brains of people with Alzheimer disease these plaques proliferate, especially in the hippocampus, a brain structure crucial for memory.

The most common cause of dementia, characterized by gradual deterioration of memory and personality and marked by the formation of plaques of beta-amyloid protein and tangles of tau in the brain. (Sometimes called senile dementia of the Alzheimer type.)

Twisted masses of threads made of a protein called tau within the neurons of the brain; a normal brain contains some beta-amyloid tau, but in brains of people with Alzheimer disease these tangles proliferate, especially in the hippocampus, a brain structure crucial for memory.

Deterioration of the amygdala and frontal lobes that may be the cause of 15 percent of all dementias. (Also called frontotemporal lobar degeneration and, in the DSM-5, frontotemporal NCD.)

A chronic, progressive disease that is characterized by muscle tremor and rigidity, and sometimes dementia; caused by a reduction of dopamine production in the brain.

A form of neurocognitive disorder characterized by sporadic, and progressive, loss of intellectual functioning caused by repeated infarcts, or temporary obstructions of blood vessels, which prevent sufficient blood from reaching the brain.

The final stage in Maslow’s hierarchy of needs, characterized by aesthetic, creative, philosophical, and spiritual understanding.