Sophie Billioti de Gage, PhD student, Bernard Bégaud, professor, Fabienne Bazin, researcher, Hélène Verdoux, professor, Jean-François Dartigues, professor, Karine Pérès, researcher, Tobias Kurth, director of research, Antoine Pariente, associate professor
Université Bordeaux Segalen, F-33000 Bordeaux, France, INSERM, U657, F-33000 Bordeaux, CHU de Bordeaux, F-33000 Bordeaux, Centre Hospitalier Charles Perrens, F-33000 Bordeaux, INSERM, U897, F-33000 Bordeaux, Division of Preventive Medicine, Brigham and Women’s Hospital, Boston, MA, USA, NSERM, U708-Neuroepidemiology, F-33000 Bordeaux
BMJ 2012; 345 doi: 10.1136/bmj.e6231 (Published 27 September 2012)
Benzodiazepine use and risk of dementia: prospective population based study
Objective To evaluate the association between use of benzodiazepines and incident dementia.
Design Prospective, population based study.
Setting PAQUID study, France.
Participants 1063 men and women (mean age 78.2 years) who were free of dementia and did not start taking benzodiazepines until at least the third year of follow-up.
Main outcome measures Incident dementia, confirmed by a neurologist.
Results During a 15 year follow-up, 253 incident cases of dementia were confirmed. New use of benzodiazepines was associated with an increased risk of dementia (multivariable adjusted hazard ratio 1.60, 95% confidence interval 1.08 to 2.38). Sensitivity analysis considering the existence of depressive symptoms showed a similar association (hazard ratio 1.62, 1.08 to 2.43). A secondary analysis pooled cohorts of participants who started benzodiazepines during follow-up and evaluated the association with incident dementia. The pooled hazard ratio across the five cohorts of new benzodiazepine users was 1.46 (1.10 to 1.94). Results of a complementary nested case-control study showed that ever use of benzodiazepines was associated with an approximately 50% increase in the risk of dementia (adjusted odds ratio 1.55, 1.24 to 1.95) compared with never users. The results were similar in past users (odds ratio 1.56, 1.23 to 1.98) and recent users (1.48, 0.83 to 2.63) but reached significance only for past users.
Conclusions In this prospective population based study, new use of benzodiazepines was associated with increased risk of dementia. The result was robust in pooled analyses across cohorts of new users of benzodiazepines throughout the study and in a complementary case-control study. Considering the extent to which benzodiazepines are prescribed and the number of potential adverse effects of this drug class in the general population, indiscriminate widespread use should be cautioned against.
© 2012 BMJ Publishing Group Ltd