The ABCD (Anticholinergics, Benzodiazepines, Cognition and Dementia) study is comprised of three work packages that will be drawn together to evaluate the evidence for exploring whether anticholinergic medication, benzodiazepine or Z-drug use lead to cognitive decline and increased dementia risk.
Work package 1 - Primary Care Studies
We are using routine primary care data collected through the Clinical Practice Research Datalink (CPRD), to examine whether long-term prescriptions for Anticholinergics, Benzodiazepines and Z-drug are associated with greater dementia incidence in the older UK population.
Work package 2 - Cohort Studies
We are using data from various cohort studies, including the MRC Cognitive Function and Ageing Study (MRC CFAS) and The Irish Longitudinal Study on Ageing (TILDA), to examine whether Anticholinergic, Benzodiazepine and Z-drug use are associated with cognitive decline. Using MRC CFAS we are also able to look at whether neuropathological changes occur for those with long-term exposure to Anticholinergics, Benzodiazepines or Z-drugs.
Work package 3 - Systematic Reviews
Finally, we will evaluate and synthesise the available international evidence from various sources as well as the results from our observational studies to answer the questions as to whether Anticholinergic, Benzodiazepine and Z-drug use are associated with cognitive decline and increased dementia incidence.
Public Patient Involvement
We are working closely with the Alzheimer's Society who have funded Research Network Volunteers to act as study monitors and service user representatives on our study steering committee. The monitors contribute to our protocol development by sharing their experiences of psychoactive medication use and their view of the balance between the benefits of medication use and potential cognitive decline. Monitors meet the study team to regularly discuss study progress. They will be particularly concerned with the dissemination phase of our study, making sure that lay summaries of results are accessible and avoid possible misinterpretation.