Studies: Common Prescription Drugs Linked to Increased Dementia Risk | The Hearty Soul
In March 2015, researchers published a prospective cohort study in JAMA Internal Medicine called “Cumulative Use of Strong Anticholinergics and Incident Dementia.” The University of Washington and Seattle healthcare system, Group Health, conducted the long-term study which tracked 3,434 men and women who were aged 65 and up, and had no dementia when the study began. 
The team accessed every participant’s history of drug use for the previous decade, including both over-the-counter and prescription drugs. Over a 7-year timeline, they followed up with all the participants every two years, during which 797 participants developed dementia (637 of whom developed Alzheimer’s disease).
As researchers looked back on what those 797 individuals took, anticholinergic drugs became the main suspect. The most common anticholinergics participants used were tricyclic antidepressants, first-generation antihistamines, and bladder antimuscarinics. Compared to those who didn’t take anticholinergic drugs, people who did for as little as three years were 54% more likely to develop dementia.