The impact of chronic benzodiazepine use on cognitive evolution in nursing home residents.

ABSTRACT

OBJECTIVE: Chronic use of benzodiazepines and Z-drugs (BZD/Zs) has been linked to cognitive decline. In this one-year prospective cohort study, we explored the impact of chronic BZD/Z use on cognitive decline compared to nonusers. METHODS: In cognitively capable BZD/Z users and nonusers in 10 Belgian nursing homes, we investigated cognition with the MiniMentalStateExamination(MMSE) at baseline and one year. A decrease of ≥ 4 points on the MMSE (clinically relevant decrease) was used in multiple logistic regression. We collected baseline demographics, functional, psychometric and social characteristics potentially influencing cognition. RESULTS: In both the 131 BZD/Z users and 95 nonusers, the cognition decreased significantly over time, but without significant difference between the groups. Clinically relevant decrease was present in 34% BZD/Z users and 27% nonusers (NS). Controlled for age, gender, education and BZD/Z use, the significant risk factors for clinically relevant cognitive decline were depression, hearing and functional impairment. Frequent reading was associated with less MMSE decrease. Our findings could not demonstrate with statistical significance that BZD/Z use was associated with fast cognitive decline. The risk factors for fast decline were depression, hearing and functional impairment, and the absence of a reading attitude. In addition, BZD/Z use and depression were associated, indicating a complex relationship.