In an analysis of test scores, researchers found that older adults who took anticholinergic drugs to treat urinary incontinence or another disorder had a rate of cognitive function decline 1.5 times faster than those who didn't take the drugs.

Every year for nearly 8 years, researchers tested 870 older Catholic priests, nuns, and brothers for cognitive decline. Participants had to complete tasks such as naming as many fruits as they could in 1 minute and reciting a string of numbers forward and backward. Almost 80% of them took one or more anticholinergic drugs to treat conditions such as urinary incontinence, hypertension, asthma, and Parkinson's disease. Incontinence drugs such as tolterodine (Detrol) and oxybutynin (Ditropan) were among the most potent and most frequently used of all of the anticholinergics. They control incontinence by relaxing bladder smooth muscle and preventing bladder spasms.

Findings held true even after researchers controlled for confounding variables, such as age. They didn't find any link between the drugs and Alzheimer's disease.

Reporting their findings at a meeting of the American Academy of Neurology, the researchers said that health care providers should do baseline cognitive testing on patients before prescribing these drugs and consider alternative nonpharmacologic therapies, such as biofeedback and toileting schedules, for treating incontinence.