Treatment of Alzheimer's disease: current approaches and promising developments

Alzheimer's disease (AD) is characterized by a gradual decline in 3 domains: cognition, behavior, and function. Ideally, an effective treatment would target all 3 types of impairment. However, available treatments for AD diminish only certain symptoms and cannot halt the dementing process. Most pharmacologic agents currently available or in development target a specific symptom cluster (e.g., cognitive loss), and are based on the known neurobiology of the disease (e.g., neurotransmitter deficit) or hypothesized antidementia approaches (e.g., anti-inflammation, antioxidation). Two currently available cholinesterase inhibitors improve memory and other aspects of cognition during short-term treatment. Additional cholinergic agents will soon become available. Other promising agents under study for cognitive enhancement or protection include vitamin E, selegiline, estrogen, and nonsteroidal anti-inflammatory drugs. As scientists uncover the basic pathogenetic mechanisms of AD, additional treatments will likely emerge. Therapies for behaviors associated with dementia (e.g., depression, agitation, anxiety) are sometimes effective. Choices of specific medications, including antidepressants, antipsychotics, and anxiolytics, depend on specific side-effect profiles. Psychotherapies aimed at enhancing cognition are ineffective for dementia but nonpharmacologic interventions may minimize depression and agitation and may improve quality of life.