Toggle Main Menu Toggle Search

Open Access padlockePrints

Anticholinergic drugs and risk of dementia: case-control study

Lookup NU author(s): Professor Dame Louise Robinson, Professor Carol Brayne, Professor Fiona MatthewsORCiD



This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0).


Study question What is the association between dementia incidence and level of exposure to different classes of anticholinergic medication over the previous 20 years? Methods We performed a case-control study nested within the UK Clinical Practice Research Datalink (CPRD). 40,770 patients aged 65-99 years and diagnosed with dementia between April 2006 and July 2015, and 283,933 controls without dementia were matched 7:1 on date, sex, age, deprivation level of the area of the general practice, and years of available data history. We compared prescriptions of anticholinergic medications coded by the Anticholinergic Cognitive Burden scale between cases and controls, controlling for medical conditions, health factors and other medication use. Anticholinergics were classified by class and quantity prescribed in exposure windows between 4 and 20 years prior to dementia diagnosis. Study answer and limitations Greater dementia incidence was observed for patients prescribed greater quantities of anticholinergic antidepressants, urological and antiparkinson medications. Gastro-intestinal anticholinergics were not associated with dementia. Despite extensive control for covariates, as an observational study residual confounding cannot be excluded as a possible explanation for our findings. What this study adds This study adds estimates for the risk of dementia associated with long term exposure to several classes of commonly used anticholinergic medications. The association between anticholinergics and future dementia incidence varies considerably by class. The association between anticholinergic antidepressants, anticholinergic urologicals, and anticholinergic antiparkinson medications is robust up to 20 years before dementia incidence. Funding, competing interests, data sharing This research was funded by the Alzheimer’s Society (AS-PG-2013-017). The authors report no conflicts of interest beyond personal fees received from Thame Pharmaceuticals to YL and from Astellas Pharmaceuticals to IM, NC and CF. Data used in this study is available from CPRD. Full code lists are available from the authors on request.

Publication metadata

Author(s): Richardson K, Fox C, Maidment I, Steel N, Loke YK, Arthur A, Myint PK, Grossi CM, Mattishent K, Bennett K, Campbell NL, Boustani M, Robinson L, Brayne C, Matthews FE, Savva GM

Publication type: Article

Publication status: Published

Journal: BMJ

Year: 2018

Volume: 361

Print publication date: 28/04/2018

Online publication date: 25/04/2018

Acceptance date: 07/03/2018

Date deposited: 17/03/2018

ISSN (print): 0959-535X

ISSN (electronic): 1756-1833

Publisher: BMJ Group


DOI: 10.1136/bmj.k1315


Altmetrics provided by Altmetric


Funder referenceFunder name
This research was supported by the Alzheimer’s Society (AS-PG-2013-017).