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Chronic Insomnia / Insomnia Disorder

Clinical Presentation

The clinical presentation of insomnia disorder includes the night-time symptoms (difficulty falling and/ or staying asleep including waking too early, present for at least 3 nights per week for 3 months), and daytime sequelae.

Insomnia disorder is characterised by self-reported ‘Difficulties Initiating and/or Maintaining Sleep’ (DIMS).

Clinical presentation of insomnia disorder includes the following night-time symptoms:

  • Difficulty initiating sleep defined by sleep latency (time taken to fall asleep >30 min)
  • Difficulty maintaining sleep (wake periods >30 min) and unable to fall back to sleep
  • Early waking (termination of sleep >30 minutes before desired wake time) and unable to fall back to sleep

The insomnia disorder’s sleep difficulty is:1

  • Present for at least 3 nights per week for 3 months or more
  • Occurs despite adequate opportunity for sleep - insomnia is not defined by feelings of ‘non-restorative sleep’ as the isolated nocturnal complaint
  • Causes clinically significant distress or impairment in social, occupational, educational, academic, behavioural, or other important areas of daytime functioning

The night-time symptoms are accompanied with one or more of the following daytime sequelae:

  • Fatigue
  • Irritability
  • Anxiety
  • Stress
  • Concerns and worries
  • Impaired attention, concentration and memory
  • Mood disturbance
  • Headaches
  • Pervasive malaise
  • GI symptoms
  • Deterioration in work performance
  • Low libido, erectile dysfunction

People with insomnia can report daytime sleepiness, however high levels of daytime sleepiness may also indicate other sleep/medical disorders e.g. obstructive sleep apnoea (OSA), depression, or inadequate opportunity for sleep.

It is important not to confuse insomnia disorder and other sleep-wake conditions or disorders that require different and specific treatments or advice. These include:

  • Obstructive sleep apnoea (OSA) - the insomnia should be conceptualised as a co-morbid condition which is responsive to targeted treatment with CBTi 2
  • Short sleepers (no daytime dysfunction present)
  • Chronic sleep restriction (inadequate opportunity to sleep, daytime dysfunction present)
  • Circadian rhythm disorders (e.g. delayed / advanced sleep-wake phase disorder)
  • Parasomnias, sleep waking, night terrors
  • Substance or medication induced sleep disorder (e.g. heavy coffee/cola consumption, bronchodilators, glucocorticoids, alcohol)

Insomnia can present as an acute (<3 months), or chronic disorder (≥3 months). Very acute insomnia (e.g. <2 weeks) is likely associated with an obvious underlying precipitating factor (e.g. acute pain, work stress, side-effect of new medication). Acute insomnia symptoms do not persist in most patients. However a minority quickly develop independent perpetuating factors and may require targeted assessment and management with CBTi.


AHI - Apnoea-Hypopnoea Index
BBTi - Brief Behavioural Therapy for Insomnia
BMI - Body Mass Index (kg/m2)
BQ - Berlin Questionnaire
CBTi - Cognitive Behavioural Therapy for Insomnia
CELL - Coblation Endoscopic Lingual Lightening
COPD - Chronic Obstructive Pulmonary Disease
CVA - Cerebrovascular Accident
CPAP - Continuous Positive Airway Pressure
CSA - Central Sleep Apnoea
DASS - Depression Anxiety Stress Scale
DBAS - Dysfunctional Beliefs and Attitudes about Sleep
DBP - Diastolic Blood Pressure
DIMS - Difficulties Initiating and/or Maintaining Sleep
DISE - Drug-Induced Sleep Endoscopy
DISS - Daytime Insomnia Symptom Scale
ENT - Ear Nose and Throat
ESS - Epworth Sleepiness Scale
FOSQ - Functional Outcomes of Sleep Questionnaire
FSH - Follicle-Stimulating Hormone
FTP - Friedman Tong Position
GP - General Practitioner
HANDI - RACGP Handbook of Non-Drug Interventions
HGNS - Hypoglossal Herve Htimulation
ISI - Insomnia Severity Index
K10 - Kessler Psychological Distress Scale
MAD - Mandibular Advancement Device
MAS - Mandibular Advancement Rplint
MBS - Medicare Benefits Schedule
MMA - Maxillomandibular Advancement Surgery
MRA - Mandibular Repositioning Appliance
ODI - Oxygenation Desaturation Index
OSA - Obstructive Sleep Apnoea
PLMD - Periodic Limb Movement Disorder
PT - Positional Therapy
PTSD - Post-Traumatic Stress Disorder
PSG - Polysomnography
QSQ - Quebec Sleep Questionnaire
REM - Rapid Eye Movement
RFTB - Radiofrequency Thermotherapy of the Tongue Base
SBP - Systolic Blood Pressure
SCI - Sleep Condition Indicator
SE - Sleep Efficiency
SF36 - Short-Form (36) Health Survey
SMILE - Submucosal Minimally Invasive Lingual Excision
SNRIs - Serotonin-Norepinephrine Reuptake Inhibitors
SOL - Sleep Onset Latency
SSRI - Selective Serotonin Reuptake Inhibitors
TFTs - Thyroid Function Tests
TIB - Time In Bed
TORS - Transoral Robotic Surgery
TST - Total Sleep Time
UPPP - Uvulopalatopharyngoplasty
WASO - Wake After Sleep Onset

Quick links


  1. International Classification of Sleep Disorders, 3rd ed. Darien, IL: American Academy of Sleep Medicine; 2014; American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 5th ed. Arlington VA: American Psychiatric Publishing 2013
  2. Sweetman A et al. Cognitive and behavioral therapy for insomnia increases the use of continuous positive airway pressure therapy in obstructive sleep apnea participants with co-morbid insomnia: A randomized clinical trial. Sleep 2019;42(12)