7 Old age psychiatry7.10 Sleep disorders in older people
7.10 Sleep disorders in later life
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Written by Resident Doctor Committee · Published
What normal ageing does to sleep
Normal ageing makes sleep lighter, shorter, more broken and less efficient, and each polysomnographic measure moves in a fixed direction.
Measure | Change with age |
|---|---|
Total sleep time | Shorter |
Slow-wave sleep | Decreases, particularly in men |
Rapid eye movement (REM) sleep | Relatively preserved compared with slow-wave sleep |
Waking after sleep onset and arousals | Increase, so sleep is lighter and more broken |
Sleep efficiency | Falls, and may keep falling after 60 |
Sleep timing | Earlier |
Circadian signals weaken through changes in the suprachiasmatic nucleus, lower melatonin amplitude and less effective light input, which cataract and little time outdoors make worse.
Sleep need changes less than the ability to keep sleep consolidated.
Sleep efficiency falls with long time in bed and daytime naps: six hours asleep in ten hours in bed gives 60%.
A complaint of poor sleep does not by itself establish insomnia disorder or justify a hypnotic.
Chronic insomnia
Chronic insomnia is persistent difficulty starting or maintaining sleep, or early waking, despite opportunity, with daytime consequences, typically at least three nights a week for three months.
It can be diagnosed and treated alongside depression, pain or another disorder.
Other sleep disorders in later life
Disorder | Core features | Points to remember |
|---|---|---|
Obstructive sleep apnoea | Witnessed apnoeas, snoring, unrefreshing sleep, nocturia; occurs without obesity | Home respiratory polygraphy first; treat with continuous positive airway pressure; zopiclone is contraindicated in severe apnoea |
Restless legs syndrome | Urge to move the legs at rest, worse in the evening, eased by movement | Check ferritin and transferrin saturation; dopaminergic drugs cause augmentation |
REM sleep behaviour disorder | Loss of REM atonia lets people act out dreams, often later in the night | Predicts synucleinopathy: about 6.3% a year, three quarters by 12 years |
Circadian rhythm disorders | Advanced phase gives an early but intact rhythm; dementia gives short sleep periods across day and night | Treat with consistent routines, daytime activity and correctly timed light |
Treatment
Cognitive behavioural therapy for insomnia is first-line for chronic insomnia, using stimulus control, adjusted time in bed, work on unhelpful beliefs and relaxation, adapted for cognition and frailty.
Hypnotics in adults over 60 add about 25 minutes of sleep, with a number needed to treat of about 13 against about 6 for an adverse event.
Benzodiazepines and Z-drugs cause residual sedation, falls, cognitive impairment, respiratory depression, tolerance and withdrawal.
Sedating antihistamines add anticholinergic harm: delirium, urinary retention and constipation.
Prolonged-release melatonin 2 mg is licensed for primary insomnia at age 55 and over, taken one to two hours before bed for up to 13 weeks.
Insomnia in dementia with falls
Melatonin is preferred for insomnia in an older person with dementia who is falling. It acts on the circadian system through melatonin receptors with little next-day sedation, whereas gamma-aminobutyric acid type A (GABA-A) hypnotics, sedating antihistamines and sedating antidepressants impair balance and alertness.
Trazodone may help in dementia but causes orthostatic hypotension, falls, hyponatraemia and QT effects.
Mirtazapine should not be prescribed simply because it sedates.
Antipsychotics are not sleep treatments in dementia, because they raise stroke and mortality risk.
Non-drug care comes first: personalised daylight, activity, exercise and sleep education.