Sedative-hypnotic use of diphenhydramine in a rural, older adult, community-based cohort: effects on cognition.

OBJECTIVE: The authors sought to identify patterns and associations of prescription and over-the-counter sedative-hypnotic use in an older, rural, blue-collar, community-based cohort in southwestern Pennsylvania over 10 years.

METHODS: A group of 1,627 individuals age 65 and over were recruited and assessed during 1987-1989 and re-assessed during approximately biennial waves. Data included sleep medications, demographics, depressive symptoms, sleep complaints, and cognitive functioning (Mini-Mental State Exam [MMSE]).

RESULTS: At Waves 1 through 5, the mean age of the cohort increased from 73.4 to 80.5 years. Use of prescription sedative-hypnotics (primarily benzodiazepines) increased from 1.8% to 3.1%, and over-the-counter sedative-hypnotic use (primarily diphenhydramine) increased from 0.4% to 7.6%. At Wave 5 (1996-1998), 8.17% of the sample reported using diphenhydramine as a sleep aid. After adjusting for age and sex, diphenhydramine use was associated with higher education and more depressive symptoms, the latter becoming nonsignificant after controlling for initial insomnia. MMSE became significantly associated with diphenhydramine use when 143 subjects with dementia were excluded from the analysis.

CONCLUSION: As the cohort aged, prescription sedative-hypnotic use remained relatively stable, whereas over-the-counter sedative use, principally diphenhydramine, increased substantially. The association of this drug with cognitive impairment in persons without dementia highlights its potential for causing adverse reactions in older adults.