When a neuropsychologist or other professional in the field of psychology or psychiatry sees a person exhibiting symptoms of Alzheimer's, a set of criteria is often used to help make an accurate diagnosis. The Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition), also known as the DSM-IV, outlines a detailed set of criteria for the diagnosis of Alzheimer’s.
First, multiple cognitive deficits must be present, one of which must be memory impairment. In addition to problems with memory, one or more of the following must be displayed:
- Aphasia -- a deterioration of language abilities, which can manifest in several ways
- Apraxia -- difficulty executing motor activities, even though movement, senses, and the ability to understand what is being asked are still intact
- Agnosia -- an impaired ability to recognize or identify objects, even though sensory abilities are intact
- Problems with executive functioning, such as planning tasks, organizing projects, or carrying out goals in the proper sequence
In order to meet the criteria for Alzheimer’s disease, the deficits must affect one’s ability to hold a job or volunteer position, fulfill domestic responsibilities, and/or maintain social relationships. The deficits must also represent a significant decline from the person’s previous level of functioning.
Alzheimer’s disease involves a gradual onset and progressive worsening of symptoms. In order to receive a diagnosis of Alzheimer’s, the deficits can't be due to another medical condition, such as Parkinson’s disease, thyroid problems, or alcoholism. Similarly, the symptoms can't occur exclusively during an episode of delirium, or be better explained by a psychological disorder such as depression or schizophrenia.
Source:
American Psychiatric Association (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: Author.
