Review, Aug/21: Is there a link between the use of benzos/Z-drugs and dementia?

The full title of this Portuguese study is "Is there a link between the use of benzodiazepines and related drugs and dementia? A systematic review of reviews".

 

https://pubmed.ncbi.nlm.nih.gov/34403113/

 

Abstract

 

Purpose: Benzodiazepines (BZDs) and related drugs (BZRDs) are commonly used to treat diverse psychiatric disorders due to their anxiolytic, hypnotic and sedative properties, despite their known associated side effects, including acute consequences on cognition. Recently, some studies have also suggested that long-term cognitive effects may coexist, as the increased risk of cognitive decline and dementia. This review aims to appraise and summarise published synthesis studies on the risk of dementia development due to BZDs/BZRDs use.

 

Methods: A comprehensive systematic search was carried out in PubMed, Web of Science, Cochrane Library and Epistemonikos databases. Grey literature and hand search of the studies' reference lists were undertaken. Meta-analysis, systematic and non-systematic reviews were included. Neither language nor date restrictions were applied. Search results other than synthesis studies were excluded. The methodological quality of the included reviews was analysed with AMSTAR-2 and SANRA tools.

 

Results: Overall, 877 records were initially retrieved and 15 complied with the inclusion criteria. From these, five were systematic reviews with meta-analysis, two were systematic reviews and eight were non-systematic reviews. Most of the primary studies included in the analysed reviews found an association between BZDs/BZRDs use and subsequent dementia, with meta-analysis studies reporting an increased risk for users (ORs ranging from 1.38 to 1.78). However, the considerable clinical and methodological heterogeneity of the primary studies makes it difficult to establish a causal relationship.

 

Conclusion: Although hampered by the heterogeneity between the studies, the present findings suggest an association between BZDs/BZRDs use and increased risk of dementia in older adults.

I think there is many studies re this and they cant seem to agree sadly. 

 

 

https://ajp.psychiatryonline.org/doi/10.1176/appi.ajp.2020.20040375  1 June 2020

 

In this issue of the Journal, Danish researchers Osler and Jørgensen (14) report that a “large cohort study did not reveal associations between use of benzodiazepines or Z-drugs and subsequent dementia, even when exposures were cumulated or divided into long- and short-acting drugs.” Their large case-controlled survey carefully identified a sample of individuals who had “any use” of benzodiazepines (and Z-drugs) over a decade. Prescription data and valid patient diagnostic information were used to assess any possible association between benzodiazepine use and the development of dementia. Covariates eliminated factors that might affect the conclusions (e.g., alcohol and substance use, other psychiatric drugs, and sociodemographic variables). The authors, who are well known in the field, concluded that there is no evidence to support the association between benzodiazepine use (and Z-drugs) and the development of dementia. They even added: “Some results were compatible with a protective  effect.

Yes, there have been numerous studies looking at this particular issue, and, as yet, it doesn't seem there is agreement. There can be so many confounding factors.