A new report from the University of Washington links long-term use of anticholinergic medications and dementia. Anticholinergic drugs block the action of acetylcholine. This substance transmits messages in the nervous system. In the brain, acetylcholine is involved in learning and memory. In the rest of the body, it stimulates muscle contractions. Anticholinergic drugs include some antihistamines, tricyclic antidepressants, medications to control overactive bladder, and drugs to relieve the symptoms of Parkinson’s disease. The study found that people who used anticholinergic drugs were more likely to have developed dementia as those who didn’t use them. Dementia risk increased with the cumulative dose. Taking an anticholinergic for the equivalent of three years or more was associated with a 54% higher dementia risk than taking the same dose for three months or less. Safer alternatives to anticholinergic drugs exist.