Benzodiazepine use and cognitive function among community-dwelling elderly.
OBJECTIVE
To evaluate the relation between benzodiazepine use and cognitive function among community-dwelling elderly.


METHODS
This prospective cohort study included 2765 self-reporting subjects from the Duke Established Populations for Epidemiologic Studies of the Elderly. The subjects were cognitively intact at baseline (1986-1987) and alive at follow-up data collection 3 years later. Cognitive function was assessed with the Short Portable Mental Status Questionnaire (unimpaired versus impaired and change in score) and on the basis of the number of errors on the individual domains of the Orientation-Memory-Concentration Test. Benzodiazepine use was determined during in-home interviews and classified by dose, half-life, and duration. Covariates included demographic characteristics, health status, and health behaviors.


RESULTS
After control for covariates, current users of benzodiazepine made more errors on the memory test (beta coefficient, 0.35; 95% confidence interval [CI], 0.10 to 0.61) than nonusers. Further assessment of the negative effects on memory among current users suggested a dose response in which users taking the recommended or higher dose made more errors (beta coefficient, 0.57; 95% CI, 0.26 to 0.88) and a duration response in which long-term users made more errors (beta coefficient, 0.39; 95% CI, 0.05 to 0.73) than nonusers. Users of agents with long half-lives and users of agents with short half-lives both had increased memory impairment (beta coefficient, 0.32; 95% CI, 0.01 to 0.64 and beta coefficient, 0.38; 95% CI, 0.02 to 0.75, respectively) relative to nonusers. Previous benzodiazepine use was unrelated to memory problems, and current and previous benzodiazepine use was unrelated to level of cognitive functioning as measured with the other 4 tests.


CONCLUSIONS
The results suggested that current benzodiazepine use, especially in recommended or higher doses, is associated with worse memory among community-dwelling elderly.
Hanlon
J T
JT
Department of Medicine, Duke University Medical Center, USA.
Horner
R D
RD
Schmader
K E
KE
Fillenbaum
G G
GG
Lewis
I K
IK
Wall
W E
WE
Landerman
L R
LR
Pieper
C F
CF
Blazer
D G
DG
Cohen
H J
HJ
D000368:Aged; D000369:Aged, 80 and over; D014151:Anti-Anxiety Agents / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D001569:Benzodiazepines; D003071:Cognition / Q000187:drug effects*; D005260:Female; D006207:Half-Life; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects; D011159:Population Surveillance; D011446:Prospective Studies; D012111:Residence Characteristics; D013997:Time Factors
D014151:Anti-Anxiety Agents; D001569:Benzodiazepines