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 features

• 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