Neurologist Jack Tsao, M.D., of the Uniformed Services University of Bethesda, Md., and colleagues analyzed "the medication use and cognitive test scores of 870 older Catholic priests, nuns, and brothers [average age 75] who participated in the Religious Orders Study at Chicago's Rush University Medical Center." Approximately "80 percent of the study participants took one or more of a class of drugs called anticholinergics, including drugs for high blood pressure, asthma, Parkinson's disease, and incontinence drugs such as Detrol (tolterodine) and Ditropan (oxybutynin)." The researchers followed the participants "for nearly eight years, testing [them] yearly for cognitive decline," and found that those "who took the drugs had a 50 percent faster rate of cognitive decline compared to those who didn't take any," even after adjusting for "other risk factors for memory loss, such as age."

According to HealthDay (4/17, Doheny), "Anticholinergic drugs are a class of medicines that work by blocking the binding of a brain chemical called acetylcholine to its receptor in nerve cells." Dr. Tsao explained that individuals "need acetylcholine for [good] memory." Research published in 2006 in the BMJ previously "found that elderly people taking anticholinergics had poorer performance on memory and other tests than those who didn't take the drugs." Notably, in Dr. Tsao's study, participants not on anticholinergic medications showed an overall "decline in cognitive performance of about 0.5 on the scale used," but "[t]hose on the medicines showed a decline of 1.5." In particular, Dr. Tsao and colleagues found that drugs "used for bladder problems and Parkinson's disease impaired memory about three times as much."

Related Links:

- "Common Medications May Harm Memory in Older People," Kathleen Doheny, HealthDay, April 17, 2008.