James M Turnbull
I do not want two diseases,
one nature made,
one doctor made.
The diagnosis of Alzheimer's disease is more dependent on intellectual impairment and memory loss than on behavioral change. However, it is the behavioral disturbances that greatly affect the quality of life not only for the patient but also for the family and the caregivers. These behavioral changes, described in detail in other chapters of this book, include agitation, wandering, screaming, aggression, violence, and inappropriate sexual acting out.
Drugs used to treat these behaviors do not affect the overall course of Alzheimer's disease. They are merely symptomatic treatments.
A close relationship exists between depression and dementia, one that is classically illustrated by the most tragic of Shakespeare's characters, King Lear. The early stages of Alzheimer's disease are frequently associated with the characteristic signs and symptoms of a mood disorder, including anhedonia (loss of pleasure in things that were formerly enjoyed), insomnia, low mood, crying spells, hopelessness, change in appetite, lethargy, and even thoughts of suicide. The frequency of depressive disorders in patients with dementia may be as high as 20%.
Phamacotherapy of behavioral disturbances and depression is both appropriate and in some cases life saving, but it is also fraught with danger. The physiological changes that take place with aging affect the pharmacokinetics and pharmacodynamics of drugs. Most patients older than 75 are taking more than one medication, which leads to problems with compliance, drug-drug interactions, and iatrogenic illness. Frequently, a close look at the combination of drugs a patient is taking is the key to explaining the appearance of new symptoms.