Article
DENVER—Sleep medication, when administered in recommended dosages at bedtime, can significantly impair next-morning short- and long-term memory, according to data presented at the 30th Anniversary Meeting of the Associated Professional Sleep Societies. Additionally, the medication significantly impairs psychomotor speed in healthy adults, but not in the elderly.
Joris C. Verster, PhD, Associate Professor in the Division of Pharmacology at Utrecht University in the Netherlands, and colleagues conducted two meta-analyses on the next-morning effects of hypnotic drugs. In one analysis, they looked at the drugs’ effects on short- and long-term memory functioning in healthy adults and in the elderly. In another study, they examined the next-morning effects on psychomotor speed and motor control in the same two age groups. For these meta-analyses, Dr. Verster and colleagues identified 33,969 potentially relevant articles.
Joris C. Verster, PhD
Morning-After Effects on Memory
Studies were included if they assessed next-morning short- and long-term memory after bedtime administration of recommended dosages of hypnotic drugs and were double-blind, placebo-controlled, and conducted in healthy volunteers, and if sufficient data were reported. Separate analyses were performed for adults (ages 18 to 65) and for elderly healthy volunteers (age 65 or older).
In adults, eight studies assessing next-morning short-term memory (after bedtime administration of nitrazepam, triazolam, temazepam, flurazepam, melatonin, zaleplon, lormetazepam, or zolpidem) and five studies assessing long-term memory (after bedtime administration of triazolam, nitrazepam, zopiclone, flurazepam, or zolpidem) were included in the meta-analysis. The analysis revealed that next-morning short- and long-term memory were significantly impaired.
In the elderly, three studies assessing next-morning short-term memory (after bedtime administration of flurazepam, zolpidem, or temazepam) and three studies assessing long-term memory (after bedtime administration of flurazepam, zolpidem, or temazepam) were included in the meta-analysis. This analysis revealed that in the elderly, next-morning short-term memory was significantly impaired, but no significant impairment was detected in long-term memory.
Morning-After Effects on Psychomotor Speed and Motor Control
Studies were included in the analysis if they assessed next-morning effects on psychomotor speed or motor control after bedtime administration of recommended dosages of hypnotic drugs. As in the meta-analyses described above, studies also had to be double-blind, placebo-controlled, and conducted in healthy subjects, and to provide sufficient data.
In adults, 15 studies assessing next-morning psychomotor speed and five studies assessing next-morning motor control were included in the meta-analysis. This analysis revealed that next-morning psychomotor speed was significantly impaired, whereas next-morning motor control was not.
In the elderly, six studies assessing next-morning psychomotor speed and three studies assessing next-morning motor control were included in the meta-analysis. This analysis revealed that in the elderly, next-morning psychomotor speed and motor control were not significantly impaired. Taken together, the analyses show that skills and abilities that are relevant to daily activities such as driving a car or job performance may be impaired the day after using hypnotic drugs.
—Glenn S. Williams