Chronic insomnia: when bad sleep becomes a disorder

Chronic insomnia is a sleep complaint that persists and comes with distress or problems in daytime life. It is recognised as a disorder in its own right, not only a symptom of something else. ^[1][7]

What the research says

Chronic insomnia has a working definition: dissatisfaction with how long or how well you sleep, trouble getting to sleep or staying asleep, and real distress or impairment in the day. ^[1] It is common. In a Canadian survey of 2,000 adults, 40.2% had at least one insomnia symptom three or more nights a week in the past month, 19.8% were dissatisfied with their sleep, and 13.4% met the full criteria for insomnia. Only about 13% had ever asked a health professional about their sleep. ^[2] It also carries a longer-term risk: across 21 studies that followed people over time, those with insomnia at the start had roughly twice the odds of later depression. ^[3] On treatment, the European and American guidelines agree that CBT-I is the first thing to try. ^[5][6] In plain terms, if your sleep has been poor for months and your days are suffering, you are far from alone, most people never ask for help, and there is a recommended treatment.

The studies behind this

• Definition: dissatisfaction with sleep duration or quality, trouble getting to sleep or staying asleep, and significant distress or daytime impairment. ^[1]
• Canadian survey (Morin, 2011): 2,000 adults. 40.2% had at least one insomnia symptom three or more nights a week in the past month. 19.8% were dissatisfied with their sleep. 13.4% met full criteria for insomnia. ^[2]
• Care-seeking: only about 13% of respondents had ever consulted a health professional about sleep. ^[2]
• Depression risk (Baglioni, 2011): across 21 long-term studies, people with insomnia at the start had roughly twice the odds of later depression (odds ratio 2.1 to 2.6 depending on the model). ^[3]
• Treatment: CBT-I is the recommended first treatment. ^[5][6]

How is chronic insomnia different from a rough patch?

Most people have short spells of poor sleep around stress, illness or travel, and brief waking at night is a normal part of sleep. The third edition of the international classification of sleep disorders (ICSD-3) made significant changes to how insomnia is classified. ^[7] Reviews describe a move away from treating insomnia purely as a symptom, towards recognising it as a disorder in its own right. ^[1] Cognitive models propose that what a person does and thinks about sleep can keep the problem going. ^[4]

We have not cited a single numeric cut-off here because the sources we could verify for this article describe the definition in terms of persistence, distress and daytime impact. Your clinician will apply the formal criteria.

What keeps it going?

A widely cited cognitive model proposes a loop: worry about sleep and its daytime effects raises arousal, attention turns to sleep-related threats, the deficit is overestimated, and the anxiety may add to a real loss of sleep. ^[4] This is a theoretical model with supporting evidence, not a settled account of every case.

How is it assessed?

The European guideline recommends:

• a clinical interview covering sleep and medical history;
• sleep questionnaires and sleep diaries;
• an overnight sleep study (polysomnography) when another sleep disorder such as a breathing or limb-movement disorder is suspected, when insomnia does not respond to treatment, and for some other indications;
• actigraphy (a wrist movement monitor) not as routine evaluation, though it may help in differential diagnosis. ^[5]

What does treatment look like?

• First: CBT-I, in person or digitally. ^[5][6] The ways to get it in this country are compared in CBT-I options in Canada.
• If CBT-I is not enough: a short-term medication can be considered with a clinician, weighing benefits, harms and costs. ^[6][5] How CBT-I and sleeping pills compare in trials has its own article.
• Other contributors: insomnia often sits alongside pain, depression or other conditions, and these deserve their own attention. ^[1]

When to see a doctor

• Sleep problems lasting months, or affecting mood, work or safety.
• Symptoms that may point to another sleep disorder. The European guideline names breathing-related and limb-movement disorders as ones to evaluate if suspected. ^[5]
• Low mood, or any thoughts of harming yourself. Contact a doctor or emergency services straight away.

Where evidence is thin

• Prevalence figures depend on the definition used and the survey method. The Canadian estimate above used the older DSM-IV-TR and ICD-10 criteria. ^[2]
• The depression link shows increased risk; it does not prove that treating insomnia prevents depression, although the authors suggest early treatment programs might help. ^[3]

If you recognise this pattern, Small Hours can help you track your sleep and work through CBT-I week by week. You can sign up at trysmallhours.com.

General education, not medical advice.