Cholinergic therapy for neuropsychiatric symptoms in neurologic disorders.

Acetylcholine is a modulatory central nervous system (CNS) neurotransmitter involved in diverse brain processes. Historically, drugs that increase CNS cholinergic transmission have been investigated primarily for relieving cognitive symptoms in Alzheimer"s disease (AD). Emerging from these efforts are recent findings that several cholinesterase-inhibitor agents also have a beneficial effect on selected noncognitive symptoms in AD, such as apathy, psychosis, and purposeless motor behaviors. The broad psychotropic effects of cholinergic agents observed in AD and other degenerative conditions highlight potential symptom-based therapeutic indications for these drugs across a variety of neurologic disorders.