There is usually no single cause of insomnia but, in addition to medical causes, there are a number of factors known to contribute, including certain personality traits, lifestyle habits and life situations.
The most common form is acute insomnia triggered by a change in the patient's life situation.
If the patient reacts to insomnia by worry, it may lead to a state of hyperalertness which in turn will perpetuate (chronic) insomnia (functional insomnia).
A careful history is crucial in evaluation, and a sleep diary is a useful additional tool.
A good doctor-patient relationship and a non-pharmacological approach are the primary elements oftreatment.
Prevalence
Transient insomnia is reported to occur in one third of the adult population and chronic insomnia in just under one tenth.
Insomnia is also common among children and adolescents.
Insomnia is more common in women than in men and it becomes more common with age.
predisposing factors (familial history of insomnia, hyperarousability, i.e. ”a light sleeper”, personality traits, behavioural patterns)
precipitating factors (chronic or acute strain/stress at work or other life situation, change in health status)
perpetuating factors (the mechanisms of psychophysiological insomnia, see above, changes in sleep habits leading to insomnia, e.g. too early a bedtime or excessive amount of time spent in bed, or an increased use of stimulants such as caffeine).
It is difficult for insomniacs to estimate accurately the duration of broken and light sleep (the average length of sleep often significantly underestimated).
Even small amounts of stimulants can affect sleep.
Caffeine (adenosine antagonist) may adversely affect sleep, particularly among sensitive individuals, regardless of the time of consumption.
Smokers sleep less well than non-smokers.
Even a fairly small amount of alcohol (< 3 units) will lighten sleep and lessen its refreshing effect.
Insomnia is a common symptom of stressful life situations and of almost all psychiatric disorders.
In the elderly insomnia is associated, in particular, with other concurrent illnesses (comorbid insomnia), whereas in middle-aged persons psychosocial factors (related e.g. to work or family) have a stronger impact.
Many physical disorders are also associated with insomnia, for example:
Idiopathic insomnia is rare; it starts in childhood or during adolescence and has no other recognisable causes. The patient has a positive family history and the cause of the disorder is organic, originating from the central nervous system (ICD-10 classification G47.0).
Manifestation: difficulty falling asleep (initial insomnia), middle of the night awakenings (middle insomnia), waking up too early (terminal insomnia) and/or non-restorative sleep.
Rapidity of sleep onset, repeated waking up (cause?), ability to fall back to sleep, waking up feeling refreshed?
Time spent in bed vs. duration of sleep
The onset, duration and development of insomnia, any changes in symptoms and their causes
The patient's own perception of the cause of insomnia
Sleep pattern before the onset of symptoms
Subjective assessment of the amount of sleep needed
Sleep environment
Effect on well-being and performance the following day
Degree of tiredness (dropping off to sleep, i.e. is the patient sleepy?)
Daytime naps
Attention, concentration, memory, proneness to accidents and mistakes
Mood (depression or insomnia-induced dysphoria?)
Physical perceptions.
Assess whether the patient has symptoms that indicate an insomnia disorder:
The clinical examination and differential diagnostics aim at detecting or excluding e.g. other sleep disorders (particularly sleep apnoea and restless legs syndrome), psychiatric illnesses, drug-induced insomnia and somatic causes.
Stimulus control therapy is the most studied and effective method, sleep restriction may prove effective and relaxation training leads to good outcomes.
Pharmacotherapy
The maximum dose must not be exceeded, and the medicine should be taken as a single dose at bedtime.
The half-life of the medicine should be considered and the patient informed about possible residual effects that persist until the following morning or day (e.g. accident proneness, fatigue and other cognitive disturbances, fitness to operate in traffic).
Insufficient data exist on hypnotic use exceeding 3 months, and it is not possible to estimate the efficacy (or safety) of long-term use.
The treatment of any underlying conditions may also be considered as insomnia treatment (e.g. an antidepressant for depression, an analgesic for pain or a dopamine agonist for restless legs syndrome).
References
Kronholm E, Partonen T, Härmä M et al. Prevalence of insomnia-related symptoms continues to increase in the Finnish working-age population. J Sleep Res 2016;25(4):454-7. [PubMed]
Davidson JR, Dickson C, Han H. Cognitive behavioural treatment for insomnia in primary care: a systematic review of sleep outcomes. Br J Gen Pract 2019;69(686):e657-e664. [PubMed]