Insomnia
Insomnia disorder is characterized by persistent difficulty falling asleep, staying asleep, or returning to sleep after early waking, occurring at least three nights per week for three months or more, and producing daytime impairment. It is a discrete DSM-5-TR diagnosis distinct from short-term sleep disturbance.
Overview
Insomnia disorder is a clinical condition involving persistent dissatisfaction with sleep quantity or quality, with difficulty initiating sleep, maintaining sleep, or returning to sleep after early-morning waking. It is one of the most prevalent sleep disorders and one of the most prevalent mental-health conditions overall.
The DSM-5-TR places insomnia disorder within the Sleep-Wake Disorders category. Diagnosis requires that the difficulty occur at least three nights per week, last at least three months despite adequate opportunity for sleep, and cause clinically significant distress or impairment in social, occupational, educational, academic, behavioural, or other areas of functioning. The DSM-5-TR moved away from the older distinction between “primary” and “secondary” insomnia, recognizing that insomnia frequently co-occurs with other conditions and merits direct treatment regardless.
The U.S. Centers for Disease Control estimates that approximately one-third of U.S. adults report insufficient sleep, with chronic insomnia affecting approximately 10% to 15% of adults. Prevalence increases with age and is higher in women, individuals with psychiatric or medical comorbidity, and shift workers.
Insomnia is frequently characterized by hyperarousal — sustained physiological, cognitive, or emotional activation that interferes with the natural transition to sleep. Many individuals with insomnia describe being “tired but wired” — physically exhausted yet mentally activated. Cognitive components include worry about sleep itself, performance anxiety around falling asleep, and rumination during night waking.
Untreated chronic insomnia is associated with increased risk for depression, anxiety disorders, cardiovascular disease, metabolic dysregulation, accidents, and reduced occupational performance and quality of life. Crucially, chronic insomnia rarely resolves spontaneously; without treatment, it tends to entrench rather than improve. Conversely, evidence-based treatments — particularly cognitive behavioural therapy for insomnia (CBT-I) — produce clinically significant and durable improvement in 70% to 80% of individuals who complete treatment.
Signs and symptoms
- Difficulty falling asleep — Sleep onset taking longer than 30 minutes, often despite tiredness. Lying awake with active mind is a common experience.
- Difficulty maintaining sleep — Frequent or prolonged night waking, often with difficulty returning to sleep, sometimes lasting for hours.
- Early-morning waking — Waking earlier than desired with inability to return to sleep, even when total sleep duration has been short.
- Non-restorative sleep — Even when sleep occurs, it does not feel refreshing; the person wakes feeling unrested.
- Daytime fatigue — Persistent tiredness, low energy, and reduced functional capacity throughout the day, often accompanied by difficulty initiating activities.
- Cognitive impairment — Difficulty with concentration, attention, and working memory; sometimes called "brain fog." Mistakes, slowed thinking, and reduced productivity follow.
- Mood disturbance — Irritability, low mood, or anxiety driven or amplified by sleep disturbance; can also drive sleep problems in a bidirectional pattern.
- Anxiety about sleep itself — Anticipatory worry about whether tonight's sleep will come, performance anxiety around the act of sleeping, and clock-watching during night waking.
- Rumination during night waking — Active mental processing — work, relationships, sleep itself — that begins or amplifies during night waking and prevents return to sleep.
- Hyperarousal — Sustained physiological activation — elevated heart rate, body temperature, cortisol — that interferes with the natural transition to sleep, often present even in absence of obvious worry.
Diagnostic context
Insomnia disorder in the DSM-5-TR requires dissatisfaction with sleep quantity or quality, with one or more sleep-related complaints (difficulty initiating sleep, maintaining sleep, or early-morning waking with inability to return to sleep). Symptoms must occur at least three nights per week, persist for at least three months despite adequate opportunity for sleep, and cause clinically significant distress or impairment.
Diagnosis typically combines clinical interview, sleep history, and self-report instruments. The Insomnia Severity Index (ISI) is the most widely used self-report measure. Sleep diaries, in which the individual tracks sleep over one to two weeks, provide important diagnostic and treatment-monitoring data. Polysomnography (overnight sleep study) is not routine for insomnia diagnosis but is appropriate when other sleep disorders (sleep apnea, periodic limb movement disorder) are suspected.
Differential diagnosis includes other sleep disorders (sleep apnea, restless legs syndrome, circadian rhythm disorders), medical conditions (chronic pain, hyperthyroidism, gastroesophageal reflux), psychiatric conditions (anxiety disorders, depression, PTSD), substance effects (caffeine, alcohol, stimulants, withdrawal states), and medication side effects. Insomnia frequently co-occurs with these and warrants direct treatment regardless.
Causes and risk factors
Insomnia arises from interaction of predisposing, precipitating, and perpetuating factors — often described as the “3-P model” (Spielman).
Predisposing factors
Genetic factors, temperamental traits (anxious or ruminative cognitive style), and individual differences in sleep architecture or arousal-regulation create baseline vulnerability. Family history of insomnia is common.
Precipitating factors
Acute stressors — bereavement, work pressure, medical illness, relationship change, time-zone travel — frequently trigger short-term sleep disturbance. Most individuals recover within weeks once the stressor passes. The transition from acute to chronic insomnia involves perpetuating factors.
Perpetuating factors
Behavioural and cognitive responses to short-term sleep loss often inadvertently maintain the problem. Common perpetuators include extending time in bed (hoping for more sleep), daytime napping, irregular sleep schedules, increased caffeine to manage daytime fatigue, alcohol use to initiate sleep (which fragments sleep architecture), and clock-watching during night waking. Cognitive perpetuators include worry about sleep, catastrophic predictions about consequences of sleep loss, and the development of sleep performance anxiety.
Medical and substance contributors
Many medical conditions disrupt sleep: chronic pain, gastroesophageal reflux, urinary frequency, asthma, hyperthyroidism, menopause, restless legs syndrome, and sleep apnea. Caffeine, nicotine, alcohol, stimulants, and several medications (decongestants, certain antidepressants, corticosteroids) can produce or amplify insomnia. Medical evaluation is appropriate when chronic insomnia emerges with physical symptoms.
Psychiatric comorbidity
Insomnia and psychiatric conditions have bidirectional relationships. Anxiety disorders, depression, and PTSD frequently produce insomnia, and chronic insomnia increases risk for these conditions. Treatment of insomnia often improves comorbid psychiatric symptoms and vice versa.
Typical treatments
Cognitive behavioural therapy for insomnia (CBT-I) is the first-line treatment recommended by major clinical guidelines.
Cognitive Behavioural Therapy for Insomnia (CBT-I). A multi-component intervention typically delivered in 6 to 8 sessions, including: sleep restriction therapy (limiting time in bed to actual sleep time, then gradually expanding); stimulus control therapy (re-establishing the bed-sleep association by leaving bed when not sleeping); cognitive therapy for sleep-related worry and unhelpful beliefs about sleep; relaxation training; and sleep hygiene education as adjunct. Multiple meta-analyses confirm CBT-I as more effective than pharmacotherapy in long-term outcomes, with 70% to 80% response rates and durable gains.
Digital CBT-I (dCBT-I). Internet-delivered or app-based CBT-I has substantial evidence and can be effective for individuals who cannot access in-person specialist care. Programs vary in quality; clinician-supported digital programs typically outperform self-guided ones.
Pharmacotherapy. Several medication classes are approved for insomnia: benzodiazepine receptor agonists (zolpidem, eszopiclone, zaleplon), orexin receptor antagonists (suvorexant, lemborexant), and melatonin receptor agonists (ramelteon). Sedating antidepressants (low-dose doxepin, trazodone, mirtazapine) are commonly prescribed off-label. Pharmacotherapy is generally reserved for short-term use or as adjunct to CBT-I; long-term medication-only treatment is less effective and carries dependence and tolerance risks. Decisions should be made with a physician.
Lifestyle and adjunctive interventions. Sleep hygiene practices — consistent sleep schedule, dark and cool sleep environment, no screens before bed, limited caffeine and alcohol, regular exercise (not close to bedtime) — support sleep but are typically insufficient alone for chronic insomnia. They are part of CBT-I rather than substitutes for it.
Treatment of comorbid conditions. When insomnia co-occurs with another condition (depression, anxiety, sleep apnea, chronic pain), addressing both is generally more effective than treating either alone. CBT-I is often the appropriate insomnia component.
When to seek help
Professional consultation is warranted when sleep difficulty persists for more than three months, occurs at least three nights per week, and causes daytime impairment in functioning, mood, or quality of life. Earlier intervention prevents the entrenchment that turns short-term sleep disruption into chronic insomnia.
Immediate medical evaluation is appropriate if insomnia is accompanied by loud snoring or witnessed apneas (suggesting obstructive sleep apnea), restless legs (suggesting restless legs syndrome), nighttime gasping, or significant daytime sleepiness despite adequate time in bed.
In Canada, free 24-hour mental-health support is available through 9-8-8: Suicide Crisis Helpline (call or text 988). For sleep-specific care, family physicians can provide initial evaluation and refer to sleep medicine specialists or psychologists trained in CBT-I. The Canadian Sleep Society maintains professional directories.
Frequently asked questions
How much sleep do I actually need?
Is melatonin effective for insomnia?
Will sleeping pills work long-term?
Why do I sleep worse when I worry about sleep?
What is sleep restriction therapy?
Can insomnia be cured?
References
- American Psychiatric Association. (2022). Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR).
- American Academy of Sleep Medicine. (2017). Clinical Practice Guideline for the Pharmacologic Treatment of Chronic Insomnia in Adults.
- Riemann, D. et al. (2017). European guideline for the diagnosis and treatment of insomnia. Journal of Sleep Research, 26(6), 675-700.
- Edinger, J. D. et al. (2021). behavioural and psychological treatments for chronic insomnia disorder in adults: An American Academy of Sleep Medicine clinical practice guideline. Journal of Clinical Sleep Medicine, 17(2), 255-262.
- Spielman, A. J. et al. (1987). A behavioural perspective on insomnia treatment. Psychiatric Clinics of North America, 10(4), 541-553.
Find the pattern behind what's been feeling hard
A few simple questions to help surface the concerns that may fit best.
Find Your PatternFind a Therapist by City
Browse therapy availability by city to see local and virtual options, explore services, and connect with a clinician who can serve your area.
Find a Therapist by Province
Browse therapy options by province to see which clinicians are available to work with clients in your region.
Trusted by Leading Psychology & Mental Health Organizations Across Canada
ShiftGrit Psychology & Counselling is professionally regulated, certified, and recognized by leading psychology and mental-health organizations across Canada. These associations reflect our commitment to ethical practice, clinical standards, and evidence-informed therapy through Identity-Level Therapy and Reconditioning.
Trusted By Alberta’s Leading Psychology & Mental Health Organizations
ShiftGrit Psychology & Counselling is professionally regulated, certified, and recognized by leading psychology and mental-health organizations across Alberta and Canada. These associations reflect our commitment to ethical practice, clinical standards, and evidence-informed therapy through Identity-Level Therapy and Reconditioning.
Regulated and affiliated across Alberta’s leading psychology, counselling, and mental-health organizations.
Regulated and affiliated across Canada’s leading psychology, counselling, and mental-health organizations.
