Insomnia in the elderly can have many different causes, frequently in combination (). A precise differential diagnosis is therefore required for appropriate treatment. Common causes of insomnia in the elderly are:
(b) organic problems – cardiovascular symptoms, nocturia, chronic pain, bronchitis and asthma;
(c) sleep apnoea and sleep-disordered breathing;
(d) restless legs syndrome and periodic limb movements during sleep;
(e) maladaptive sleep habits.
(f) drug and alcohol use;
(g) persistent psychophysiological insomnia (‘behavioural insomnia’) with sleep-preventing associations, increased somatised tension.
In all age groups, insomnia often occurs secondary to psychiatric disorders such as depression, psychosis or dementia. Depressive insomnia can be treated with the tricyclic antidepressant trimipramine () or by other antidepressants with sedative potential such as amitriptyline, doxepine or trazodone. The usage of neuro-leptics should be restricted to patients with psychosis and for agitated demented patients.
Physical disorders (e.g. nocturia, cardiac failure, respiratory diseases and chronic pain) are further common causes of disrupted sleep, especially in the elderly. Thus, severe physical disease, a secondary depression and extensive bed rest may further contribute to sleep disturbance. An appropriate analgesic medication can help to manage insomnia in chronic pain patients. Rescheduling the intake of diuretics may help to reduce nocturia.
An additional important cause of reduced sleep quality is a disturbance of nocturnal respiratory function, such as sleep apnoea syndrome. Ancoli-Israel et al () and Ancoli-Israel & Coy () reported that 10% of randomly selected elderly subjects had 10 or more apnoeas per hour of sleep and 24% had five or more per hour. Sleep-related breathing disorders are associated with hypertension, cardiac arrhythmias, heart failure, impaired memory and frequent napping during the daytime, and may enhance the risk of brain infarction (). Ingraim reported that vigilance maybe impaired only in those older adults suffering from more severe sleep apnoea.
An important differential diagnosis in patients complaining of insomnia is restless legs syndrome (RLS) (). The prevalence of this disorder increases with ageing, and is present in about 5% of the elderly. These patients experience uncomfortable sensations, typically located in the legs. These sensations encompass pain, burning, tingling, ‘insects crawling over the skin’ and an urge to move one’s legs; they usually occur in the late evening and early night. The afflicted usually have severe sleep disturbances, and polysomnographic recording frequently shows a massive disruption of the sleep profile, as well as many periodic leg movements (PLMs), inducing arousals during sleep or preventing sleep onset (). It is important to consider RLS in differential diagnosis, as this disorder often remains undiagnosed, with its sensory symptoms attributed to other disorders such as polyneuropathy and various orthopaedic problems. Restless legs syndrome can be effectively treated by dopaminergic agents such as L-dopa (). The prevalence of PLMs during sleep as an isolated phenomenon without the symptoms of RLS is as high as about 30% in elderly individuals (), but there is still some controversy over the relevance of this to insomnia.
Many old people acquire poor sleep habits such as spending too much time in bed and frequent daytime napping. These practices were often introduced by the patients in response to their sleeping problem. Very often expectations of sleep are far too high. This was shown in our epidemiological study (), in which 46% of the elderly individuals wished for a sleeping time of nine hours or more.
Educating patients in good sleep habits and changing maladaptive sleeping habits is therefore an essential component of insomnia management, especially in the elderly. The behavioural measures should include restriction and regulation of time spent in bed, avoidance of daytime napping, enhancement of daytime activities and exposure to daylight. Campbell & Dawson () and Campbell et al () reported beneficial effects of light therapy for geriatric insomnia with significant effects on sleep EEC and daytime performance (). Behavioural treatments for insomnia might also include muscle relaxation therapy, stimulus control therapy, cognitive techniques such as cognitive relaxation, discontinuation of ruminations, and reorganisation of sleep-incompatible thoughts ().
The use of hypnotics for elderly patients should be much more fastidious than that described by the epidemiological data. Sedative medication can induce daytime carryover effects, and thus promote inactivity and daytime napping. Benzodiazepines rapidly induce tolerance and rebound insomnia after discontinuation of the drug (). Impaired memory, a characteristic side-effect of benzodiazepines, and an increased risk of hip fractures () due the muscle-relaxing effect of the substances must also be given special consideration.
Alternative drugs for insomnia include herbal substances and sedative antidepressants, which may be useful not only for depressive insomnia but also for primary insomnia (). The effect of melatonin on sleep disturbances is currently being evaluated in a large number of studies. The secretion of melatonin, which is inversely correlated with ageing (), plays an important role in the entrainment of the circadian system to external time cues. With the concurrent weakening of the circadian rhythm in old age, melatonin might be especially useful for the treatment of insomnia in the elderly. Haimov et al () and Garfinkel et al () reported a significant amelioration of sleep problems in elderly insomniacs following melatonin replacement therapy. However, information on the effectiveness and side-effects after long-term use of melatonin are still lacking, so that recommendations cannot presently be given.
In summary, the complaint of insomnia is very common in older individuals, and is frequently caused by multiple factors such as the physiological changes of sleep in ageing, disturbances of the circadian rhythm, psychiatric and organic disease, sleep apnoea syndrome, RLS and maladaptive sleep habits. A differential therapy can be improved if all these factors are considered.
Selections from the book: “Late-Onset Mental Disorders. The Potsdam Conference”, 1999.