Overview
Insomnia
1. Clinical Overview
Summary
Insomnia is a persistent difficulty with sleep initiation, Duration, Consolidation, or Quality despite adequate opportunity and circumstances for sleep, resulting in Daytime Impairment. It is the most common sleep disorder, affecting approximately 30% of adults intermittently and 10% with chronic insomnia. Insomnia is classified as Short-Term (Acute) or Chronic (≥3 nights/week for ≥3 months) (ICSD-3). It may be Primary (Idiopathic) or Comorbid with other conditions (Mood disorders, Anxiety, Chronic pain, Medical conditions). A key perpetuating factor is Conditioned Arousal and Maladaptive Behaviours (Excessive time in bed, Clock-watching, Daytime naps). First-line treatment is Cognitive Behavioural Therapy for Insomnia (CBT-I), which addresses dysfunctional beliefs and behaviours. Pharmacotherapy (Hypnotics) is second-line, used short-term for acute insomnia, with the "Z-drugs" (Zopiclone, Zolpidem) being most commonly prescribed. Good Sleep Hygiene is important but insufficient alone for chronic insomnia. [1,2,3]
Clinical Pearls
"CBT-I is First-Line, Not Tablets": Cognitive Behavioural Therapy for Insomnia is more effective long-term than medication.
"Chronic = ≥3 Nights/Week for ≥3 Months": Differentiates from acute/Short-term insomnia.
"Insomnia is a Symptom and a Disorder": May be primary or secondary to other conditions (Anxiety, Depression, Pain, Sleep Apnoea).
"Watch for Sleep Apnoea": Screen for snoring, Witnessed apnoeas, Daytime sleepiness in overweight/Collar size >17 patients.
2. Epidemiology
Demographics
| Factor | Notes |
|---|---|
| Prevalence | ~30% have intermittent insomnia symptoms. ~10% meet criteria for chronic insomnia disorder. |
| Age | Increases with age. Elderly are more affected. |
| Sex | Female > Male (~1.5:1). |
Risk Factors
| Risk Factor | Notes |
|---|---|
| Mental Health Conditions | Depression, Anxiety, PTSD. Bidirectional relationship. |
| Chronic Pain | Arthritis, Fibromyalgia, Neuropathy. |
| Medical Conditions | COPD, Heart failure, GORD, Nocturia, Menopause. |
| Shift Work | Disrupts circadian rhythm. |
| Substance Use | Caffeine, Alcohol (Disrupts sleep architecture), Nicotine. |
| Medications | Steroids, Beta-blockers, SSRIs (Activating), Stimulants. |
| Stressful Life Events | Trigger acute insomnia. May become chronic. |
| Poor Sleep Habits | Irregular schedule, Screens in bed, Excessive caffeine. |
3. Pathophysiology
Spielman's 3P Model
| Factor | Description |
|---|---|
| Predisposing | Trait factors increasing vulnerability (Anxiety-prone personality, Genetic, Hyperarousal tendency). |
| Precipitating | Triggers that initiate insomnia (Stress, Life event, Illness, Jet lag). |
| Perpetuating | Factors that maintain insomnia after trigger resolves (Maladaptive behaviours: Excessive time in bed, Daytime napping, Clock-watching, Worry about sleep). |
Hyperarousal Model
- Insomnia is characterised by physiological and cognitive hyperarousal (Elevated cortisol, Increased metabolic rate, Increased beta EEG activity).
- The bed becomes associated with Wakefulness and Frustration rather than sleep.
- Conditioned Arousal: Being in bed triggers wakefulness.
4. Classification (ICSD-3)
Duration
| Type | Duration |
|---|---|
| Short-Term (Acute) Insomnia | less than 3 months. Often related to identifiable stressor. |
| Chronic Insomnia Disorder | ≥3 nights/week for ≥3 months. |
Association
| Type | Description |
|---|---|
| Primary (Idiopathic) | No clear underlying cause. |
| Comorbid (Secondary) | Associated with another condition (Psychiatric, Medical, Substance). Note: Current classification views these as "Comorbid" rather than "Secondary" – acknowledging bidirectional relationships. |
5. Clinical Presentation
Symptoms
| Symptom | Notes |
|---|---|
| Difficulty Falling Asleep (Initial Insomnia) | Lying awake for >30 mins before sleep onset. |
| Difficulty Staying Asleep (Maintenance Insomnia) | Frequent or prolonged awakenings during the night. |
| Early Morning Awakening (Terminal Insomnia) | Waking earlier than desired and unable to return to sleep. |
| Non-Restorative Sleep | Feeling unrefreshed despite adequate sleep duration. |
| Daytime Impairment | Fatigue, Mood disturbance, Concentration difficulties, Impaired work/Social functioning. |
History Taking
| Component | Notes |
|---|---|
| Sleep Pattern | Typical bedtime, Wake time, Time to fall asleep (Sleep Onset Latency), Number/Duration of awakenings, Total sleep time, Napping. |
| Daytime Symptoms | Fatigue, Sleepiness, Mood, Concentration, Function. |
| Sleep Environment | Bedroom: Light, Noise, Temperature, Partner (Snoring?). Screen use. |
| Substances | Caffeine (Time, Quantity), Alcohol, Nicotine, Recreational drugs. |
| Medications | Any sleep-affecting drugs. |
| Mental Health | Depression screen (PHQ-9), Anxiety (GAD-7). |
| Medical Conditions | Pain, Nocturia, GORD, Respiratory symptoms. |
| Sleep Apnoea Screen | Snoring, Witnessed apnoeas, Daytime sleepiness (Epworth Sleepiness Scale), BMI, Collar size. |
| Sleep Diary | 2-week diary invaluable. |
Examination
Usually unremarkable in primary insomnia.
Common presentation.
Look for signs of underlying conditions (Thyroid, Depression).
Common presentation.
Assess for obstructive sleep apnoea risk (Obesity, Large neck, Retrognathia, Tonsillar hypertrophy).
Common presentation.
6. Investigations
Sleep Diary
| Notes |
|---|
| Key Tool: 2-week sleep diary. Records bedtime, Wake time, Estimated sleep time, Naps, Caffeine/Alcohol, Subjective sleep quality. |
| Helps identify maladaptive patterns. |
Questionnaires
| Questionnaire | Purpose |
|---|---|
| Insomnia Severity Index (ISI) | Quantifies insomnia severity. |
| Epworth Sleepiness Scale (ESS) | Screens for excessive daytime sleepiness (Sleep apnoea, Narcolepsy). |
| STOP-BANG | Screens for Obstructive Sleep Apnoea risk. |
| PHQ-9, GAD-7 | Screen for depression and anxiety. |
Polysomnography (PSG)
| Indication | Notes |
|---|---|
| NOT routinely indicated for insomnia | |
| Indicated if: Suspected OSA, Periodic Limb Movement Disorder, Narcolepsy, Parasomnias. |
7. Management
Management Algorithm
INSOMNIA PRESENTATION
(Difficulty sleeping + Daytime impairment)
↓
COMPREHENSIVE ASSESSMENT
- Sleep history (Diary)
- Screen for: Anxiety, Depression, OSA, Medical causes
- Identify perpetuating factors
↓
CLASSIFY
- Short-Term vs Chronic (≥3 nights/week, ≥3 months)
- Primary vs Comorbid
↓
TREAT UNDERLYING CONDITIONS
(Depression, Anxiety, Pain, OSA, GORD)
↓
MANAGEMENT
┌────────────────┴────────────────┐
SHORT-TERM INSOMNIA CHRONIC INSOMNIA
↓ ↓
- Sleep Hygiene Advice **FIRST-LINE:**
- Address stressor **CBT-I (Cognitive Behavioural
- Short-term hypnotic Therapy for Insomnia)**
if severe (Z-drug, Max 2-4 ↓
weeks) **IF CBT-I NOT AVAILABLE /
INSUFFICIENT:**
- Sleep Hygiene
- Sleep Restriction Therapy
- Stimulus Control
↓
**SECOND-LINE (Pharmacotherapy):**
- Short-term hypnotic
- Or as adjunct to CBT-I
↓
COGNITIVE BEHAVIOURAL THERAPY FOR INSOMNIA (CBT-I)
┌──────────────────────────────────────────────────────────┐
│ **GOLD STANDARD for Chronic Insomnia** │
│ - 4-8 sessions (Individual or Group) │
│ - Online/Digital CBT-I also effective (e.g., Sleepio) │
│ │
│ **Components:** │
│ 1. **Sleep Education** │
│ 2. **Stimulus Control**: Bed for sleep/Sex only. Get │
│ out of bed if awake >15-20 mins. Fixed wake time. │
│ 3. **Sleep Restriction**: Limit time in bed to actual │
│ sleep time. Gradually increase as efficiency improves│
│ 4. **Cognitive Therapy**: Challenge dysfunctional │
│ beliefs about sleep (Catastrophising). │
│ 5. **Relaxation Techniques**: Progressive muscle │
│ relaxation, Mindfulness. │
│ 6. **Sleep Hygiene**: Supportive but insufficient alone │
└──────────────────────────────────────────────────────────┘
↓
PHARMACOTHERAPY (Second-Line, Short-Term)
┌──────────────────────────────────────────────────────────┐
│ **Z-DRUGS (Non-Benzodiazepine Hypnotics)** │
│ - Zopiclone 3.75-7.5mg nocte │
│ - Zolpidem 5-10mg nocte │
│ - Short-term use (2-4 weeks max, NICE) │
│ - Risk: Dependence, Tolerance, Rebound insomnia, │
│ Complex sleep behaviours, Falls (Elderly) │
│ │
│ **LOW-DOSE SEDATING ANTIDEPRESSANTS (Off-Label)** │
│ - Amitriptyline 10-25mg nocte │
│ - Trazodone 25-100mg nocte │
│ - Mirtazapine 7.5-15mg nocte (If depression comorbid) │
│ - Useful if: Comorbid depression/Anxiety, Neuropathic │
│ pain, Need for longer-term option │
│ │
│ **MELATONIN (Circadin - Prolonged Release)** │
│ - Licensed for >55 years, Short-term (less than 13 weeks) │
│ - Modest effect │
│ │
│ **OREXIN RECEPTOR ANTAGONISTS (Newer)** │
│ - Daridorexant, Suvorexant (Not widely available UK) │
│ │
│ **AVOID BENZODIAZEPINES** long-term (Dependence, Falls) │
└──────────────────────────────────────────────────────────┘
↓
SLEEP HYGIENE (Supportive, Not Sufficient Alone)
┌──────────────────────────────────────────────────────────┐
│ - Regular sleep schedule (Fixed wake time) │
│ - Avoid caffeine after midday │
│ - Limit alcohol (Disrupts sleep architecture) │
│ - Regular exercise (Not late evening) │
│ - Dark, Cool, Quiet bedroom │
│ - Avoid screens 1 hour before bed (Blue light) │
│ - Wind-down routine │
│ - Avoid clock-watching │
│ - Don't stay in bed awake (Get up if >15-20 mins) │
└──────────────────────────────────────────────────────────┘
8. Complications
| Complication | Notes |
|---|---|
| Depression / Anxiety | Bidirectional. Insomnia is a risk factor for developing depression. |
| Impaired Cognitive Function | Concentration, Memory, Decision-making. |
| Reduced Quality of Life | |
| Occupational Impairment | Absenteeism, Accidents. |
| Road Traffic Accidents | Increased risk. |
| Cardiovascular Risk | Chronic sleep deprivation associated with hypertension, Cardiac disease. |
| Hypnotic Dependence | With prolonged use of Z-drugs/Benzodiazepines. |
9. Prognosis and Outcomes
| Factor | Notes |
|---|---|
| CBT-I Response | ~70-80% improve. Effects sustained long-term (Better than hypnotics). |
| Pharmacotherapy | Effective short-term. High relapse on discontinuation. Tolerance. |
| Chronic Insomnia | Without treatment, Often persists. |
| Comorbid Conditions | Treating underlying condition improves insomnia (And vice versa). |
10. Evidence and Guidelines
Key Guidelines
| Guideline | Organisation | Key Recommendations |
|---|---|---|
| Insomnia | NICE | CBT-I first-line for chronic. Hypnotics short-term only. Address underlying causes. |
| Insomnia | AASM / ESRS | CBT-I recommended. Medications for short-term use or adjunct. |
Key Evidence
- CBT-I vs Pharmacotherapy: CBT-I has more durable effects. Hypnotics provide short-term benefit but risk dependence and rebound.
- Digital CBT-I: Effective and accessible (e.g., Sleepio).
11. Patient and Layperson Explanation
What is Insomnia?
Insomnia is difficulty falling asleep, Staying asleep, Or waking too early, Which causes problems during the day (Tiredness, Difficulty concentrating, Low mood).
What causes it?
- Stress or Worry: Common trigger.
- Poor Sleep Habits: Irregular schedule, Screens in bed, Caffeine.
- Mental Health: Depression and Anxiety often go hand-in-hand with insomnia.
- Physical Problems: Pain, Breathing issues, Needing to urinate at night.
What is the best treatment?
The most effective treatment is CBT for Insomnia (CBT-I). This is a structured therapy (Often 4-8 sessions, Or online courses) that helps you change unhelpful thoughts and behaviours around sleep.
What about sleeping tablets?
Sleeping tablets (Like Zopiclone) can help in the short term (A few weeks) but are not a long-term solution. They can become less effective, Be habit-forming, And make insomnia worse when you stop them.
Sleep Tips
- Keep a regular wake time (Even weekends).
- Avoid caffeine after midday.
- Make your bedroom dark, Cool, And quiet.
- Avoid screens before bed.
- If you can't sleep, Get up and do something relaxing until you feel sleepy.
12. References
Primary Sources
- National Institute for Health and Care Excellence. Insomnia. Clinical Knowledge Summary. 2022.
- Qaseem A, et al. Management of Chronic Insomnia Disorder in Adults: A Clinical Practice Guideline From the American College of Physicians. Ann Intern Med. 2016;165(2):125-133. PMID: 27136449.
- Riemann D, et al. European guideline for the diagnosis and treatment of insomnia. J Sleep Res. 2017;26(6):675-700. PMID: 28875581.
13. Examination Focus
Common Exam Questions
- First-Line Treatment: "What is the first-line treatment for chronic insomnia?"
- Answer: Cognitive Behavioural Therapy for Insomnia (CBT-I).
- Chronic Definition: "How is chronic insomnia defined?"
- Answer: Difficulty sleeping ≥3 nights/week for ≥3 months, with daytime impairment.
- Pharmacotherapy Caution: "Why should hypnotics be used cautiously?"
- Answer: Risk of Dependence, Tolerance, Rebound insomnia, Complex sleep behaviours, Falls (Elderly). Should be short-term only (2-4 weeks).
- CBT-I Component: "What is Stimulus Control in CBT-I?"
- Answer: Using the bed only for sleep and sex. Getting out of bed if unable to sleep after 15-20 minutes. Fixed wake time.
Viva Points
- 3P Model (Spielman): Predisposing, Precipitating, Perpetuating factors.
- Sleep Hygiene is Supportive, Not Curative: Insufficient alone for chronic insomnia.
- Screen for OSA and Depression: Common comorbidities/Differentials.
- Digital CBT-I: Effective and accessible option (e.g., Sleepio).
Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate specialists.