Insomnia
Persistent difficulty sleeping — causes, assessment and management
Insomnia is one of the most common sleep disorders, affecting up to one in three adults in the UK. It is characterised by difficulty falling asleep, staying asleep, or waking too early — resulting in daytime tiredness, poor concentration, and reduced quality of life. NICE recommends cognitive behavioural therapy as the first-line treatment, ahead of medication.
What is insomnia?
Insomnia is defined as persistent difficulty initiating or maintaining sleep, or non-restorative sleep, occurring at least three nights per week for at least three months (chronic insomnia). Short-term or acute insomnia lasts less than three months and is often triggered by a specific stressor. Both types cause significant daytime impairment including fatigue, poor concentration, mood disturbance, and reduced work performance. Insomnia affects all ages but is more common in older adults, women, and those with mental health conditions.
Causes & risk factors
Insomnia can be primary (no clear underlying cause) or secondary to other conditions. Common causes include anxiety and depression, chronic pain conditions, obstructive sleep apnoea (OSA), restless legs syndrome, shift work and irregular sleep schedules, medications (corticosteroids, beta-blockers, decongestants, SSRIs), caffeine and alcohol use, and environmental factors such as noise and light. Psychological factors — particularly hyperarousal and negative beliefs about sleep — play a central role in perpetuating chronic insomnia and are the target of CBT-I.
Assessment
Assessment of insomnia should include a sleep history covering sleep onset latency, number of awakenings, total sleep time, and daytime functioning. A two-week sleep diary provides invaluable objective data on sleep patterns, bedtimes, and wake times. Validated screening tools include the Epworth Sleepiness Scale (ESS — scores ≥10 suggest excessive daytime sleepiness, raising suspicion for OSA) and the Insomnia Severity Index (ISI — scores ≥15 indicate moderate-severe insomnia). Bloods may be required to exclude organic causes: TFTs, FBC, ferritin (low ferritin linked to restless legs). Polysomnography is not routinely indicated unless OSA or parasomnias are suspected.
Non-pharmacological treatment
NICE CG159 recommends Cognitive Behavioural Therapy for Insomnia (CBT-I) as the first-line treatment for chronic insomnia — ahead of sleeping tablets. An evaluation of the patient's sleep patterns, contributing factors, and previous treatment responses should guide individual management. CBT-I is effective, has no side effects, and produces durable results. Its components include: stimulus control (use bed for sleep and sex only; get up if unable to sleep after 20 minutes), sleep restriction therapy (consolidate sleep to increase sleep drive), relaxation techniques (progressive muscle relaxation, mindfulness), cognitive restructuring (challenge unhelpful beliefs about sleep), and sleep hygiene education. Sleepio is a NICE-recommended digital CBT-I programme available without prescription. Additional advice: maintain a fixed wake time every day, avoid screens for 1 hour before bed, limit caffeine intake after 2pm, keep the bedroom cool and dark, and avoid alcohol as a sleep aid — whilst it aids sleep onset, it disrupts REM sleep and worsens sleep quality overall.
When to refer
Refer to a sleep clinic if obstructive sleep apnoea is suspected — key features include habitual snoring, witnessed apnoeas, Epworth score >10, and morning headaches. Refer to psychology or IAPT if CBT-I cannot be accessed in primary care. Refer to psychiatry if comorbid depression or anxiety is driving the insomnia and is not responding to treatment in primary care. For patients on long-term Z-drugs, a supervised tapering and withdrawal plan should be arranged, with monitoring for rebound insomnia and dependence.