Summary

Chronic insomnia or insomnia disorder negatively impacts mental and physical health and leads to increased healthcare costs. At least 30% of the general population report symptoms of sleep disturbance, while 10-15% report symptoms indicative of chronic insomnia disorder.

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

Insomnia disorder includes:

• 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 difficulty falling and/or staying asleep including waking too early is:

• Present for at least 3 nights per week for 3 months
• Occurs despite adequate opportunity for sleep
• Causes clinically significant distress or impairment in social, occupational, educational, academic, behavioral, or other important areas of daytime functioning (See daytime symptoms below)

SYMPTOMS AND CLINICAL PRESENTATION

The clinical presentation of insomnia disorder includes night-time and daytime symptoms which are present for at least 3 nights per week for 3 months.

Night-time symptoms

• Self-reported frequent difficulties falling asleep at the start of the night
• Awakenings during the night with difficulties returning to sleep
• Early morning awakenings with difficulties returning to sleep

Daytime symptoms

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

Insomnia is not defined by feelings of ‘non-restorative sleep’ as the isolated nocturnal complaint.

RISK FACTORS & DEVELOPMENT

Factors of the 3P model contributing to the development of insomnia disorder include:

1. Predisposing factors that place an individual at greater risk of developing insomnia
2. Precipitating factors that trigger/cause the initial sleep disturbance
3. Perpetuating factors, including psychological, behavioural, and physiological that maintain the chronic insomnia over time, independently of the initial precipitating factors

Predisposing factors

• Increased cognitive activity including anxiety, stress, and worry
• Inappropriate expectations about sleep such as obtaining more sleep than is necessary, or obtaining an unbroken sleep throughout the night
• Genetically determined factors including increased core body temperature during the sleep period, and increased stress-reactivity

Precipitating factors

• Stressful life event including death in family, relationship difficulties, job loss, starting a new job, newborn
• Pain
• Menopause
• Shift work including hospitality work
• Travel between time zones and circadian disruption (daylight savings)
• Environmental factors (noise disturbance, temperature)
• Caffeine and alcohol
• Medication with stimulant properties
• Mental health disorders (which often have a bidirectional relationship with insomnia)
• Medical disorders including respiratory, cardiovascular, endocrine, neurological, gastro-oesophageal reflux, frequent nocturia, and itch
• Other sleep health disorders including obstructive sleep apnoea, restless legs syndrome

Perpetuating factors

• Anxiety about sleep including repeated association of the bed environment with unsuccessful attempts to initiate sleep or return to sleep after awakening
• Counter-productive compensatory behaviours including spending too much time in bed at night and/or napping during the day to make up for the lack of sleep, cancelling daytime commitments including lack of physical activity or exercising late in the day
• Inappropriate behaviours and use of sleep aids including alcohol, watching TV and mobile phone use in bed
• Misperceptions about the quality and quantity of sleep including underestimating the amount of time spent asleep, leading to increased sleep-related anxiety
• Dysfunctional beliefs about sleep such as misconception that a few brief night-time awakenings are abnormal

Cognitive Behavioural Therapy for insomnia targets these perpetuating factors to improve the insomnia.

CO-MORBID INSOMNIA

Insomnia can present as an independent condition, or co-morbid with other conditions including:

Other mental health conditions

• Depression
• Anxiety
• Post-traumatic stress disorder (PTSD)
• Alcohol dependence

Physical conditions

• Gastroesophageal reflux
• Chronic pain
• Arthritis
• Dementia
• Chronic obstructive pulmonary disease (COPD)
• Asthma
  
• Nocturia
• Hyperthyroidism
• Hypertension
• Insulin resistance
• Menopause
• Obesity

Other sleep disorders

• Obstructive sleep apnoea (OSA)
• Restless legs syndrome

Substance abuse or drug or substance use/withdrawal

As well as being a potential result of having these comorbidities, insomnia is associated with increased risk of developing co-morbidities. When co-occurring with other conditions, insomnia is responsive to targeted insomnia-treatment, which often improves management of the other condition too.

HISTORY & QUESTIONNAIRES

A diagnosis of insomnia disorder is based upon patient-reported sleep history and the use of the Sleep Condition Indicator (SCI) or Insomnia Severity Index (ISI) questionnaires.

Sleep history includes sleep quantity (See night-time symptoms above) and daytime function (See daytime symptoms above), and sleep hygiene (relating to environmental factors, physiologic factors, behaviour and habits), onset and trajectory of insomnia symptoms, previous treatments used and effect of these treatments and checking for co-morbid conditions as well as excluding other potential causes of insomnia (mental health screening tools e.g. DASS 21, K10, Oestrogen Deficiency Score, or bloods e.g. TFTs, FSH if indicated). Poor sleep hygiene may include mobile phone or TV use while in bed, spending too long in bed.

A sleep diary (paper or watch which monitors sleep patterns) can assist in the assessment of insomnia, and help patients with to monitor and recognise their sleep habits.

The following questionnaires may be of use to determine symptoms of insomnia disorder during assessment and follow-up:

• Sleep Condition Indicator (SCI) score 16 indicates probable insomnia
• Insomnia Severity Index (ISI) score ≥15 moderate to severe insomnia

TREATMENT

Non-pharmacological, cognitive and behavioural treatment strategies are the recommended treatments for insomnia disorder. Because they treat the underlying cause of insomnia, these treatments lead to long-term therapeutic improvement of sleep and daytime functioning.

Non-pharmacological, cognitive and behavioural treatment strategies include:

• Brief Behavioural Therapy for Insomnia (BBTi)
  
• Cognitive Behavioural Therapy for insomnia (CBTi)
  

Therapeutic components of BBTi include:

1. Basic sleep and sleep hygiene education
   
2. Bedtime restriction therapy
   
3. Stimulus control therapy
   
4. Relaxation techniques
   

CBTi adds cognitive restructuring to the above therapeutic components as well as having more therapeutic sessions of a longer duration.

Non-pharmacological, cognitive and behavioural treatments target the underlying perpetuating factors of insomnia disorder and can be administered by:

• GPs and other primary health care professionals, e.g. BBTi
• Clinical psychologists (with a Mental Healthcare Plan), e.g. face-to-face CBTi
• The use of digital programs, i.e. online CBTi

Patients with complex insomnia (insomnia with comorbidities) who require more specialised support, those who do not experience improvement of their insomnia disorder with BBTi or digital CBTi, or those who prefer not to use digital CBTi, can be referred to a psychologist specialising in sleep health for CBTi.

Patients can be referred to digital CBTi programs (e.g. This Way Up) while being monitored regularly for changes in symptoms, and to encourage adherence.

If pharmacotherapy is used, e.g. sedative-hypnotic medicines (benzodiazepines, 'z-drugs'), they should be used only when CBTi is not available, tolerated by patient, or patient does not respond to CBTi, at the lowest effective dose, for the shortest possible duration (i.e. <4 weeks) e.g. for acute severe insomnia (acute grief, job stress, etc.). Also a strategy to withdraw from sedative-hypnotic use should be established early to prevent patterns of long-term use and/or dependence.

Management of insomnia disorder needs to address any co-morbid medical or mental health condition, substance use or other sleep disorder that may share reciprocal relationships with the insomnia. Furthermore targeted insomnia-treatment often improves management of the co-occurring condition.