Condition of unsatisfactory sleep, either in terms of sleep onset, sleep maintenance or early waking
Aetiology
Commonly secondary to functional, mood and substance misuse disorders
Frequently present in individuals under stress
Can often be triggered by one of these factors before becoming a habit on its own, driven by anticipation of insomnia and daytime naps
Clinical presentation
Daytime sleepiness and fatigue, with consequences such as road traffic accidents
The timing of insomnia can indicate the cause:
Initial insomnia (trouble going off to sleep) is common in mania, anxiety, depressive disorders and substance misuse
Middle insomnia (waking up in the middle of the night) occurs with medical conditions such as sleep apnoea and prostatism
Late insomnia (early morning wakening) is caused by depressive illness and malnutrition (anorexia nervosa)
Management
Hypnotic drugs should be limited to the lowest effective dose for the shortest time possible, with a maximum two-week treatment period, and avoided where possible in the elderly
Manage underlying cause
About 30% of patients with primary insomnia will improve with sleep hygiene advice alone e.g. limit caffeine, avoid napping, avoid looking at screens before bed