Behavioral abnormalities in Alzheimer's disease.

Fundamental and therapeutic research into Alzheimer's disease (AD) initially focused on cognitive aspects. However, AD also frequently involves complex affective and behavioral disorders, which are currently grouped under the heading Behavioral and Psychological Signs and Symptoms of Dementia (BPSSD). BPSSD further handicap the patient in his or her daily activities and are a major source of problems for the family and other carers. Studies of these aspects must take into account various clinical aspects such as the development of reliable tools for assessment and diagnosis. BPSSD can only be understood on the basis of neuroanatomical and neurochemical findings, i.e. the link between the dysfunction of cortical-subcortical regions and networks and the onset of a particular behavioral disorder. Finally, therapeutic research must go beyond simple adaptation of an adult treatment protocol to affected elderly subjects by learning more about the different neurotransmitter systems in Alzheimer's disease.