Sleep disturbance and insomnia

Definition | Aetiology | Pathophysiology | Risk factors | Signs and symptoms | Investigations | Management

Definition

Sleep disturbance and insomnia refer to difficulties in initiating, maintaining, or obtaining restorative sleep, leading to impaired daytime functioning.

Aetiology

  • Primary insomnia: idiopathic, without underlying medical cause.
  • Secondary insomnia:
    • Psychiatric disorders (e.g., anxiety, depression, PTSD).
    • Medical conditions (e.g., chronic pain, asthma, gastro-oesophageal reflux disease).
    • Neurological disorders (e.g., Parkinson’s disease, dementia).
    • Substance use (e.g., caffeine, alcohol, stimulants, recreational drugs).
    • Shift work or jet lag.

Pathophysiology

  • Increased sympathetic nervous system activity leading to hyperarousal.
  • Disruption of circadian rhythm due to altered melatonin production.
  • Alterations in neurotransmitters regulating sleep (e.g., serotonin, gamma-aminobutyric acid [GABA]).

Risk factors

  • High levels of stress or anxiety.
  • Irregular sleep schedule or poor sleep hygiene.
  • Chronic medical conditions.
  • Use of stimulants or alcohol before bedtime.
  • Ageing (increased prevalence in older adults).
  • Night shift work.

Signs and symptoms

  • Difficulty falling or staying asleep.
  • Early morning awakenings.
  • Daytime fatigue or sleepiness.
  • Impaired concentration or memory.
  • Irritability, mood disturbances.
  • Reduced ability to cope with stress.

Investigations

  • Clinical assessment: sleep history, including sleep diary and questionnaire (e.g., Epworth Sleepiness Scale).
  • Blood tests: if metabolic or endocrine disorder suspected (e.g., thyroid function tests).

Management

1. Sleep hygiene education:

  • Maintain a regular sleep schedule.
  • Avoid caffeine, alcohol, and heavy meals before bedtime.
  • Reduce screen exposure before sleep.
  • Create a dark, quiet, and comfortable sleep environment.
  • Encourage relaxation techniques such as meditation.

2. Cognitive behavioural therapy for insomnia (CBT-I):

  • First-line treatment for chronic insomnia.
  • Addresses maladaptive thoughts and behaviours related to sleep.
  • Includes stimulus control and sleep restriction therapy.

3. Pharmacological management (short-term use only if severe):

  • Promethazine 10/25mg ON for short term.
  • Z-drugs (e.g., zolpidem, zopiclone) for short term relief.
  • Melatonin for circadian rhythm disorders.
  • Avoid benzodiazepines where possible due to dependence risk.

4. Referral:

  • Sleep specialist: if obstructive sleep apnoea or restless legs syndrome suspected.
  • Psychiatrist: if insomnia is associated with severe anxiety or depression.
PsychiatrymypanotesSleep disturbance and insomnia