Judgments of efficacy and utility in remediating either symptomatic domain in AD should take into consideration the effects of treatment on both cognitive domain and behavioral domain symptoms separately and interactively. Appropriate assessment procedures are discussed. They occur commonly in DAT, and there is evidence that they may indicate subtypes of the disorder in view of their demographic, structural, and prognostic correlates. Personality changes are very common, and these may be the earliest manifestation of dementia. Behavioral disturbances tend to be associated with advanced dementia and are particularly disruptive to caregivers.
Structural correlates suggest that some behaviors are a direct result of brain damage.
Psychiatric and behavioral features in DAT are important, as they may serve as a model for symptomatology in functional psychiatric disorders. Evaluation of changes in functional performance and activities of daily living skills is an essential aspect of the assessment of elderly individuals with chronic illness. In this paper the results of three separate investigations regarding the reliability, validity, and progressive ordinality of FAST are described. The results indicate that FAST is a reliable and valid assessment technique for evaluating functional deterioration in AD patients throughout the entire course of the illness. Because the elements of functional capacity incorporated in FAST are relatively universal and readily ascertainable, as well as characteristic of the course of AD, FAST can serve as a strong diagnostic and differential diagnostic aid for clinicians.