Common medications, when used for 1 year or more, increase the risk of dementia by 30% in a recent study looking at dementia onset in 350,000 older adults (aged 65 to 99). These medications include anticholinergic drugs – which block the effects of acetylcholine, a chemical used by nerve cells to send signals to other nerve cells and muscles – used for depression, Parkinson’s disease, and urinary incontinence. Anticholinergic drugs prescribed for asthma and gastrointestinal issues did not increase the dementia risk when compared to controls. BMJ
→Takeaway: Anticholinergic medications are prescribed to as many as 50% of older populations in the U.S. and U.K. In addition to the 2018 BMJ study described above, a 2017 study found that long-term use of anticholinergic drugs, including first-class antihistamines (Benadryl) and tricyclic antidepressants, is associated with a significant increased risk of dementia. These findings highlight the importance of embarking on a risk-benefit analysis before taking medication.