Are sleeping pills harmful in the long term?

Classic sleeping pills (benzodiazepines) have been shown to be safe for up to two to four weeks. After that, the balance no longer holds. Yet short-term use often grows into long-term use: in a Japanese cohort study of nearly 4,000 new users, 1 in 10 people were still taking the pills after twelve months. Older age, a high starting dose, and concurrent use of antidepressants were the strongest predictors of that pattern¹.

Physical dependence with long-term use is well established. There are two forms: dependence that arises from the treatment itself at low doses, and abuse at high doses. Both problems have been present for fifty years, yet are still underestimated by many prescribers².

Long-term use also impairs your cognitive functioning. Attention, reaction speed, and the ability to plan and make decisions decline measurably, even in people who have been using these medications for years. On public roads, users drove less stably, with more lane deviations. Notably, with use lasting longer than three years, on-road driving performance appeared to improve slightly, probably due to habituation, but the cognitive deficits remained fully present³. A driving simulator study found no demonstrable difference, but the groups were small, so that evidence carries little weight⁴.

Whether long-term use causes lasting changes in the brain has not yet been adequately studied. It is taken seriously as a question, but an answer is not yet available.

Newer sleeping pills, the so-called z-drugs such as eszopiclone, perform somewhat better than classic benzodiazepines. Eszopiclone helps you fall asleep an average of 12 minutes faster, results in 17 minutes less time lying awake, and provides 28 minutes more sleep per night, based on moderate-quality evidence⁵. Side effects do occur: an unpleasant aftertaste (18% more often than with placebo), dry mouth, daytime drowsiness, and dizziness. Extra caution is warranted in older adults. Z-drugs appear on the whole to produce tolerance and withdrawal symptoms less readily than classic benzodiazepines, but this has been described in a narrative review and has not been demonstrated in direct comparisons⁶.