Neurocognitive Disorders

All neurocognitive disorders were at one time classified as “dementia” because they involve similar cognitive impairment and decline, and most often impact the elderly. Although Alzheimer’s disease accounts for the majority of cases of neurocognitive disorders, several other conditions can similarly affect memory, thinking, and reasoning, and some can also affect the motor system. In addition to Alzheimer’s, these conditions include frontotemporal degeneration, Huntington’s disease, Lewy body disease, traumatic brain injury (TBI), Parkinson’s disease, prion disease, and dementia/neurocognitive issues due to HIV infection. These disorders can be categorized and diagnosed as either major in nature or mild (also known as slight cognitive impairment), depending on the severity of an individual’s symptoms. For some, such as with TBI and HIV, younger as well as older people can be affected. Major cognitive disorder is estimated to affect 1 to 2 percent of people by age 65 and as much as 30 percent of the population by age 85.