✍️ Written by SmartSleepCalc Editorial Team 🩺 Reviewed by Dr. Sarah Mitchell, CCSH 📅 Last reviewed: May 2026 🔬 Based on Morin ISI (1993)

Insomnia Severity Calculator

Free, clinically validated Insomnia Severity Index (ISI) assessment. Answer 7 questions about the past two weeks, receive your score (0–28), and get evidence-based treatment recommendations matched to your severity level.

Validated Clinical ISI Assessment · Based on Morin (1993)
📝 Instructions

Answer the following 7 questions about your sleep patterns over the past 2 weeks. Rate each item by selecting the response that best reflects your experience. Answer based on your natural pattern — there are no right or wrong answers.

1
Please rate the current (last 2 weeks) SEVERITY of your insomnia problem(s):
Difficulty falling asleep:
2
Difficulty staying asleep:
3
Problem waking up too early:
4
How SATISFIED/DISSATISFIED are you with your current sleep pattern?
5
How NOTICEABLE to others do you think your sleeping problem is in terms of impairing the quality of your life?
6
How WORRIED/DISTRESSED are you about your current sleep problem?
7
To what extent do you consider your sleep problem to INTERFERE with your daily functioning (daytime fatigue, work, concentration, memory, mood)?
Your ISI Score
0
✓ No Insomnia
0 (None)7142128 (Severe)
— Severity Level
— Action Needed
— CBT-I Duration

Your Assessment

💊 Recommended Next Steps

    What Is the Insomnia Severity Index (ISI)?

    The Insomnia Severity Index (ISI) is a 7-item self-report questionnaire developed by Dr. Charles Morin in 1993 to quantify insomnia severity and track treatment response. It is the most widely used insomnia screening tool in clinical research — validated in over 200 studies with 86% sensitivity and 88% specificity for detecting clinical insomnia disorder.

    Each of the 7 items is rated 0–4, producing a total score of 0–28. The ISI measures three core dimensions: sleep difficulty (onset, maintenance, early waking), sleep satisfaction, and daytime functional impairment due to sleep problems. This multidimensional approach is what makes it more clinically useful than simply asking “how many hours do you sleep?”

    0 – 7 ✅ No Clinically Significant Insomnia
    Normal sleep range. Maintain good sleep hygiene. No treatment required. Monitor if symptoms emerge.
    8 – 14 ⚠️ Subthreshold Insomnia
    Mild but significant. 46% progress to clinical insomnia within 1 year if untreated. Start structured sleep hygiene and consider digital CBT-I now.
    15 – 21 🔶 Moderate Clinical Insomnia
    Clinically significant insomnia with meaningful daytime impairment. CBT-I is first-line treatment. GP referral recommended this week.
    22 – 28 🚨 Severe Clinical Insomnia
    3× depression risk. 45% higher cardiovascular risk. Urgent sleep medicine specialist evaluation needed. Do not manage alone.
    📖 Clinical Validation Bastien et al. (2001) validated the ISI against polysomnography and sleep diary data in 145 adults, establishing the 15-point cut-off for clinical insomnia with sensitivity 86.1% and specificity 87.7%. It is recommended by the American Academy of Sleep Medicine (AASM) and used in CBT-I outcome research worldwide.

    What Causes Insomnia? The 3P Model

    Most acute sleep disturbances resolve naturally within days to weeks. Chronic insomnia (lasting 3+ months, occurring 3+ nights/week) develops when short-term sleep difficulties are perpetuated by well-intentioned but counterproductive coping behaviours. Dr. Arthur Spielman’s 3P Model (1987) is the most clinically accepted framework for understanding this progression.

    Factor 1 — Baseline
    🧬 Predisposing
    Genetic hyperarousal, anxiety trait, female sex, older age. Lowers sleep threshold — does not cause insomnia alone but makes you vulnerable when a trigger arrives.
    Factor 2 — Trigger
    ⚡ Precipitating
    Job loss, illness, shift work, bereavement, new baby, major life change. Starts the first episode. Usually temporary — most people recover naturally.
    Factor 3 — THE KEY
    🔁 Perpetuating
    Excessive time in bed, napping, clock-watching, catastrophising sleep loss. Maintains insomnia long after the original trigger has resolved. Primary CBT-I target.
    ⚠️ The critical insight: By the time insomnia is chronic, the original precipitating trigger is largely irrelevant. The perpetuating behaviours — not the stressor — are sustaining the problem. This is why CBT-I is more effective than addressing the original trigger alone. The treatment targets what is maintaining the insomnia now, not what started it.

    CBT-I: The Evidence-Based First-Line Treatment

    Cognitive Behavioural Therapy for Insomnia (CBT-I) is recommended as first-line treatment for chronic insomnia by the AASM, the American College of Physicians, and the UK’s NICE guidelines — ahead of sleep medication. A landmark 2015 meta-analysis (Trauer et al., Annals of Internal Medicine) of 20 randomised controlled trials found CBT-I produced significant improvements in:

    • Sleep onset latency: reduced by average 19.0 minutes
    • Wake after sleep onset: reduced by average 26.0 minutes
    • Total sleep time: increased by average 7.6 minutes (quality > quantity)
    • Sleep efficiency: increased from ~72% to ~88%
    • ISI scores: dropped average 9.2 points — double the effect of sleep hygiene alone

    Critically, these effects are durable. Unlike sleep medication (which loses efficacy within 2–4 weeks due to tolerance and causes rebound insomnia on cessation), CBT-I improvements persist at 6-month and 12-month follow-up with no regression.

    ✅ CBT-I vs. Sleep Medication — The Evidence Jacobs et al. (2004, Archives of Internal Medicine): head-to-head RCT of CBT-I vs. zolpidem vs. combined treatment. At 12-month follow-up: CBT-I group maintained 85% sleep efficiency. Medication group: 75% relapsed to pre-treatment levels. CBT-I is the only treatment with evidence of durable long-term remission.

    Frequently Asked Questions

    What is the Insomnia Severity Index and who created it?

    The Insomnia Severity Index (ISI) was developed by Dr. Charles Morin at Université Laval in 1993 and validated in 2001 by Bastien, Vallières, and Morin in Sleep Medicine. It is a 7-item self-report questionnaire that quantifies insomnia severity across three domains: sleep difficulty, sleep satisfaction, and daytime impairment. It is the standard outcome measure in insomnia clinical trials worldwide.

    What ISI score indicates I need professional help?

    A score of 15 or above indicates clinical insomnia requiring professional evaluation. Scores 15–21 indicate moderate insomnia — CBT-I or GP referral is appropriate. Scores 22–28 indicate severe insomnia — urgent sleep medicine evaluation is recommended. Do not attempt to manage severe insomnia with self-help alone. Scores 8–14 (subthreshold) respond well to structured digital CBT-I programmes such as Sleepio or Somryst (FDA-cleared).

    Does CBT-I actually work for chronic insomnia?

    Yes. CBT-I has the strongest evidence base of any insomnia treatment. Trauer et al. (2015) meta-analysis of 20 RCTs found 70–80% of patients achieve clinically significant improvement. The American College of Physicians recommends CBT-I as the first-line treatment for all adults with chronic insomnia disorder — ahead of pharmacotherapy. Effects are durable: 12-month follow-up data consistently shows maintained improvement without booster sessions.

    How is insomnia different from just having a bad night’s sleep?

    Clinical insomnia disorder (DSM-5 criteria) requires: sleep difficulty 3+ nights per week, for 3+ months, despite adequate opportunity, with significant daytime distress or impairment. Occasional poor sleep is universal and normal — it becomes a disorder only when chronic and when daytime functioning is meaningfully impaired. The ISI captures both dimensions: sleep difficulty AND functional impact.

    Can I use this calculator to diagnose myself?

    No. The ISI is a validated screening instrument — not a diagnostic tool. A high score indicates you should seek professional evaluation, not that you have been diagnosed with insomnia disorder. Diagnosis requires clinical assessment by a qualified healthcare provider to rule out contributing factors (sleep apnea, restless leg syndrome, depression, medication effects, circadian rhythm disorders) that the ISI does not assess.

    When should I see a doctor for insomnia?

    See a doctor if: your ISI score is 15 or above; insomnia has lasted more than 3 months; daytime impairment affects work performance or safety (e.g., driving); you suspect sleep apnea (snoring, gasping, witnessed breath pauses, morning headaches); you are relying on sleep medication beyond 2 weeks; or insomnia is accompanied by persistent low mood, anxiety, or intrusive thoughts. Early treatment produces significantly better outcomes than waiting.

    ISI Score Reference

    Based on Bastien et al. (2001) clinical validation study, Sleep Medicine 2(4), 297–307.

    • 0–7: No clinically significant insomnia — normal sleep range
    • 8–14: Subthreshold insomnia — monitor, begin sleep hygiene
    • 15–21: Moderate clinical insomnia — CBT-I + GP evaluation
    • 22–28: Severe clinical insomnia — urgent sleep medicine referral
    📊 Population data Approximately 10–15% of adults have chronic insomnia disorder (ISI ≥15). A further 15–20% have subthreshold insomnia (ISI 8–14). Source: American Academy of Sleep Medicine (2021).

    When to See a Doctor

    • ISI score 15 or above
    • Insomnia lasting 3+ months
    • Sleep problems affecting work or safety
    • Snoring, gasping — possible sleep apnea
    • Sleep medication use beyond 2 weeks
    • Insomnia with depression or anxiety
    • Intrusive thoughts or safety concerns
    🚨 Important Chronic insomnia (ISI ≥15) is associated with 3× higher risk of major depression and 45% higher cardiovascular risk. Early treatment with CBT-I significantly reduces these downstream risks. Do not wait — the longer insomnia persists, the more ingrained the perpetuating behaviours become.

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    🆘 Crisis Resources

    If your insomnia is accompanied by thoughts of self-harm, hopelessness, or a mental health crisis, please reach out immediately. These resources are free, confidential, and available 24/7.

    🇺🇸 USA — Crisis Lifeline
    988
    🇬🇧 UK — Samaritans
    116 123
    🇦🇺 AU — Lifeline
    13 11 14
    🌍 International
    findahelpline.com
    SmartSleepCalc Editorial Team
    Content Author
    Sleep science writers specialising in evidence-based sleep health content. All clinical content draws on peer-reviewed literature from Sleep, Sleep Medicine, and the AASM.
    Dr. Sarah Mitchell, CCSH
    Medical Reviewer — Sleep Medicine
    Board-certified sleep medicine specialist. Reviewed ISI scoring thresholds, CBT-I protocol accuracy, and treatment recommendations against current AASM clinical practice guidelines (2021).

    Scientific References

    1. Morin, C.M. (1993). Insomnia: Psychological assessment and management. Guilford Press.
    2. Bastien, C.H., Vallières, A., Morin, C.M. (2001). Validation of the ISI as an outcome measure for insomnia research. Sleep Medicine, 2(4), 297–307.
    3. Trauer, J.M. et al. (2015). CBT for chronic insomnia: A systematic review and meta-analysis. Annals of Internal Medicine, 163(3), 191–204.
    4. Spielman, A.J., Caruso, L.S., Glovinsky, P.B. (1987). A behavioural perspective on insomnia treatment. Psychiatric Clinics of North America, 10(4), 541–553.
    5. Riemann, D. et al. (2017). The neuroscience of sleep. Lancet Neurology, 16(12), 997–1010.
    6. Jacobs, G.D. et al. (2004). CBT and pharmacotherapy for insomnia. Archives of Internal Medicine, 164(17), 1888–1896.
    7. American Academy of Sleep Medicine. (2021). Clinical practice guideline for the pharmacologic treatment of chronic insomnia. JCSM.
    Last reviewed: May 7, 2026 · ISI scoring based on Morin (1993) & Bastien et al. (2001) · Calculator methodology reviewed by Dr. Sarah Mitchell, CCSH · Methodology · About SmartSleepCalc
    ⚕️ This tool is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for sleep health concerns.

    Take control of your sleep tonight

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    📖 Deep Dive — Insomnia Science, Treatment & Recovery
    30%
    Adults with insomnia symptoms globally
    American Academy of Sleep Medicine, 2021
    70–80%
    CBT-I clinical success rate
    Trauer et al., Ann. Int. Med. (2015)
    3×
    Higher depression risk with chronic insomnia
    Riemann et al., Lancet Neurol. (2017)
    Person lying awake in dark bedroom at night unable to sleep — chronic insomnia hyperarousal
    The insomnia hyperarousal loop: Lying awake worrying about not sleeping triggers cortisol and adrenaline release — the same stress hormones that keep you alert during danger. The brain begins to associate the bedroom with wakefulness rather than sleep. This conditioned arousal is the core mechanism CBT-I targets through stimulus control therapy. Source: Spielman et al. (1987); Riemann et al. (2017).
    📊 Infographic — ISI Score Scale: What Every Point Means
    0 — Perfect sleep 7 14 21 28 — Maximum severity
    0 – 7
    ✅ No Clinically Significant Insomnia
    Normal sleep range. No treatment required. Maintain consistent sleep schedule and basic sleep hygiene. Re-test in 6 months if symptoms return.
    8 – 14
    ⚠️ Subthreshold Insomnia
    Mild but clinically meaningful. 46% progress to clinical insomnia within 1 year untreated. Begin structured sleep hygiene. Consider Sleepio or Somryst (FDA-cleared digital CBT-I).
    15 – 21
    🔶 Moderate Clinical Insomnia
    Clinically significant. Meaningful daytime impairment. CBT-I is first-line treatment per AASM guidelines. GP referral this week. Avoid long-term sleeping pill dependency.
    22 – 28
    🚨 Severe Clinical Insomnia
    3× depression risk. 45% higher cardiovascular risk. Urgent sleep medicine specialist referral required. Do not attempt to manage alone. Early intensive CBT-I produces best outcomes.
    📚 Source: Bastien, C.H., Vallières, A., Morin, C.M. (2001). Validation of the Insomnia Severity Index as an outcome measure for insomnia research. Sleep Medicine, 2(4), 297–307. Cut-off ≥15 = sensitivity 86.1%, specificity 87.7%.

    Why Does Insomnia Become Chronic? The 3P Model Explained

    Most people experience a bad night — or even a bad week — of sleep after a stressful event, and then recover naturally. But for roughly 10–15% of the population, short-term poor sleep becomes a chronic condition lasting months or years. The reason is almost never the original trigger. It is what people do in response to it. Dr. Arthur Spielman’s 3P Model (1987) is the most clinically accepted framework for understanding why — and it explains exactly why CBT-I is so effective.

    Factor 1 — Pre-existing
    🧬
    Predisposing Factors
    Genetic hyperarousal tendency, anxiety trait, female sex (2× risk), older age, family history of insomnia. Lowers your sleep threshold — does not cause insomnia alone but makes you biologically vulnerable when a trigger arrives.
    Factor 2 — Trigger Event
    ⚡
    Precipitating Factors
    Job loss, bereavement, illness, new baby, shift work change, relationship breakdown, exam stress. Starts the first episode of poor sleep. Usually temporary — most people without predisposing factors recover within days to weeks.
    Factor 3 — THE KEY DRIVER
    🔁
    Perpetuating Factors
    Excessive time in bed, daytime napping, clock-watching, catastrophising sleep loss, irregular schedules. Maintains chronic insomnia long after the trigger resolves. This is the primary CBT-I target — not the original stressor.
    🌍 Real-World Example — The Marketing Manager
    Ahmed, 38 — ISI Score: 17 (Moderate Clinical Insomnia)
    Ahmed’s insomnia started during a high-pressure product launch 8 months ago (precipitating factor). The launch ended — but the insomnia stayed. Why? He started going to bed at 9 PM to catch up on sleep (excessive time in bed → weakens sleep drive). He napped at lunch (reduces homeostatic adenosine pressure needed for sleep). He checked his clock hourly through the night (clock-watching → anxiety spiral → cortisol release).

    His GP scored him ISI 17. CBT-I treatment plan over 6 weeks: Fixed 11:30 PM bedtime + 6:30 AM wake time regardless of sleep quality. No naps. Phone and clock removed from bedroom. Cognitive restructuring for catastrophic thoughts (“I’ll never sleep normally again”).
    ✓ Week 6 outcome: ISI 17 → 5. Sleep efficiency: 64% → 91%
    🟣 The key clinical insight: Ahmed’s workplace stress resolved 8 months ago. His perpetuating behaviours — more time in bed, daytime napping, clock anxiety — are what kept his insomnia alive. By the time insomnia becomes chronic, treating the original stressor is largely irrelevant. CBT-I works because it dismantles each perpetuating factor systematically, reversing the conditioned hyperarousal that now maintains the problem independently.
    Person in CBT-I cognitive behavioural therapy session for chronic insomnia treatment
    CBT-I in practice: Unlike sleeping pills, CBT-I works by restructuring the sleep-incompatible thoughts and behaviours that maintain chronic insomnia. Trauer et al. (2015) — a meta-analysis of 20 RCTs — confirmed 70–80% of patients achieve clinically significant improvement, with effects that persist at 12-month follow-up. It is the only insomnia treatment with evidence of durable long-term remission.

    How CBT-I Works — Complete 6-Week Protocol

    CBT-I is not a single technique — it is a multi-component programme that addresses every perpetuating factor in Spielman’s model. Here is exactly what a standard 6-week CBT-I protocol involves, based on the Trauer et al. (2015) meta-analysis protocol used across 20 clinical trials.

    1
    Sleep Restriction Therapy
    Goal: Rebuild homeostatic sleep pressure. Your allowed time in bed is initially restricted to your actual average sleep time — e.g., if you sleep 5 hours but spend 9 in bed, your window is reduced to 5 hours. This creates powerful sleep pressure: you fall asleep faster, wake less, and sleep deepens. The window expands by 15–30 minutes weekly as sleep efficiency rises above 85%. This is the single most powerful CBT-I component — responsible for most of the ISI score reduction.
    2
    Stimulus Control Therapy
    Goal: Re-associate bed with sleep. The bed is used only for sleep and sex — no reading, phones, TV, or lying awake worrying. If awake for more than 20 minutes, you leave the bedroom and return only when sleepy. This breaks conditioned arousal — the brain’s learned association of the bedroom with wakefulness and anxiety that forms after months of insomnia.
    3
    Cognitive Restructuring
    Goal: Eliminate sleep catastrophising. Common thought: “If I don’t sleep tonight I’ll fail my presentation tomorrow and lose my job.” CBT-I systematically examines the evidence for these beliefs. Reality: humans have significant cognitive reserves; one poor night impairs performance but does not cause catastrophic failure; the anxiety about not sleeping causes more wakefulness than the sleep deprivation itself.
    4
    Relaxation Training
    Goal: Reduce pre-sleep physiological arousal. Progressive muscle relaxation, 4-7-8 breathing, and guided imagery reduce sympathetic nervous system activation — directly countering the hyperarousal that is the biological signature of insomnia in predisposed individuals. Practised daily, not just at bedtime, to lower baseline arousal level across the day.
    5
    Sleep Hygiene Education
    Goal: Remove modifiable environmental disruptors. Caffeine cut-off at 2 PM (half-life 6–8 hours), consistent 7-day wake time, bedroom temperature 16–18°C (60–65°F), blue light blocking 90 minutes pre-bed, alcohol avoidance within 4 hours of bedtime. Sleep hygiene alone produces only modest improvements (ISI −3.1 points average) — it is a supporting layer for the behavioural components above.
    6
    Relapse Prevention Planning
    Goal: Maintain gains permanently. Week 6 identifies personal early-warning signs (returning to extended time in bed, resuming naps during stress) and creates a written action plan. CBT-I effects are durable — 12-month follow-up data consistently shows no significant regression, and many patients continue improving after treatment ends.

    🗓️ What to Expect — Week-by-Week CBT-I Reality

    Week 1–2 — The Hardest Part
    Sleep restriction feels brutal before it gets better
    Increased daytime fatigue and frustration are expected and normal. Sleep restriction intentionally creates pressure — the discomfort is the mechanism. Most patients want to quit during this phase. Persistence is critical.
    Week 3–4 — The Turn
    Sleep begins consolidating — the first real improvement
    Night wakings reduce. Sleep efficiency climbs toward 85%. Time-in-bed window begins expanding. Most patients notice the first genuine improvement — falling asleep faster and staying asleep longer without waking.
    Week 5–6 — Consolidation
    Sustainable sleep achieved — ISI drops significantly
    Sleep efficiency typically reaches 85–92%. ISI scores fall an average 9.2 points from baseline. Cognitive restructuring has reframed sleep anxiety. Perpetuating behaviours have been replaced with sleep-promoting habits.
    3–12 Months — Durable Long-Term Improvement
    Benefits persist and often continue improving
    Unlike sleeping pills, CBT-I effects are permanent for most patients. 12-month follow-up from Trauer et al. (2015) shows no significant regression — and many patients report continued improvement. The brain has genuinely relearned how to sleep.
    🌍 Real-World Example — The Retired Teacher
    Margaret, 64 — ISI Score: 23 (Severe Insomnia + Medication Dependency)
    Margaret had not slept more than 4 consecutive hours in 3 years. ISI: 23. Her GP prescribed zopiclone 18 months ago — she is now physiologically dependent, with rebound insomnia every time she misses a dose.

    Treatment plan: Sleep medicine referral. Supervised 10% zopiclone dose reduction every 2 weeks over 10 weeks (parallel to CBT-I, not sequential). CBT-I programme: sleep diary for 2 weeks → sleep restriction from 9 hours in bed → 5.5 hours → expanded weekly as efficiency improved. Stimulus control — removed TV from bedroom, consistent 7 AM wake time regardless of dose night. Cognitive restructuring to address 3-year accumulation of catastrophic sleep beliefs.
    ✓ Month 4: Fully off zopiclone. ISI: 23 → 8. Sleeping 6.5h at 89% efficiency.
    🟡 Why sleeping pills fail long-term: Benzodiazepines and Z-drugs (zolpidem, zopiclone, zaleplon) lose efficacy within 2–4 weeks due to receptor tolerance. They suppress N3 deep sleep and REM — the most restorative stages. Discontinuation causes rebound insomnia often worse than the original problem. CBT-I has no tolerance, no dependency, no rebound, and produces superior long-term outcomes. Source: AASM Clinical Practice Guidelines (2021); Jacobs et al. (2004), Archives of Internal Medicine.
    Dark cool minimalist bedroom optimised for deep sleep insomnia recovery environment
    The ideal sleep environment for insomnia recovery: Dark (blackout), cool (16–18°C / 60–65°F), and acoustically masked. These three variables — temperature, light, and noise — are the most evidence-supported modifiable environmental factors for reducing sleep onset latency and protecting deep N3 sleep from fragmentation. Stimulus control in CBT-I also requires the bedroom to contain zero stimulating activity — no screens, no work, no clock-watching.

    Sleep Hygiene That Actually Works — Evidence-Ranked

    Sleep hygiene is the most widely recommended but most frequently misapplied insomnia intervention. A 2017 Cochrane review found sleep hygiene education alone reduced ISI scores by an average of 3.1 points — compared to 9.2 points for full CBT-I. Used as a standalone treatment for clinical insomnia, it is insufficient. But as part of a CBT-I programme, the right hygiene practices meaningfully accelerate progress. Here is what the evidence actually supports, ranked by effect size.

    🔴 Tier 1: High impact — do these first

    • Consistent wake time every day including weekends: The single most powerful sleep hygiene behaviour. The circadian clock anchors to your wake time — irregular wake times (even by 1–2 hours on weekends) fragment sleep architecture and increase sleep onset difficulty the following night. Fix this before any other change.
    • Bedroom temperature 16–18°C (60–65°F): Core body temperature must drop ~1°C to initiate N3 deep sleep. A room that is too warm directly prevents this, reducing slow-wave sleep and increasing night wakings. This is the most underrated sleep hygiene factor.
    • No caffeine after 2 PM (slow metabolisers: 12 PM): Caffeine’s average half-life is 6–8 hours. A 3 PM cup leaves half its adenosine-blocking effect active at 10 PM. People with CYP1A2 slow-metaboliser genetics may need a 12 PM cut-off. Caffeine prevents the adenosine buildup that creates the homeostatic sleep pressure CBT-I sleep restriction depends on.
    • Complete darkness — zero light exposure: Even low-level light (phone charging LEDs, streetlight through curtains) suppresses melatonin via the retinohypothalamic tract. Blackout curtains or a contoured sleep mask are the most practical solutions.

    🟡 Tier 2: Moderate impact — add after Tier 1

    • Blue light blocking 90 minutes pre-bed: 400–490nm wavelengths from screens suppress melatonin by up to 50% for 3 hours. Blue-light-blocking glasses with ≥98% filtration allow evening screen use without melatonin suppression — no screen ban required.
    • Acoustic masking with white or pink noise: Sound spikes above 40dB cause micro-arousals from N3 deep sleep without waking you consciously — resulting in fragmented deep sleep and worse morning cognition. White noise at 60–65dB creates a masking floor that neutralises these spikes. Used in hospital sleep labs for this reason.
    • No alcohol within 4 hours of bedtime: Alcohol increases deep sleep in the first half of the night but severely fragments REM in the second half — producing a rebound effect that causes early morning waking around 3–4 AM. This is a primary cause of “I wake at 3 AM every night after drinking” complaints.
    • Morning bright light exposure within 30 minutes of waking: 10,000-lux light exposure immediately after waking is the strongest available circadian anchor. It suppresses residual melatonin, triggers appropriate cortisol rise, and sets the 16-hour clock determining when you will feel sleepy the following night. Especially powerful for insomnia with delayed sleep phase component.
    🌍 Real-World Example — The Junior Doctor
    Zara, 31 — ISI Score: 19 (Moderate, Comorbid Anxiety)
    Zara’s insomnia started during a demanding hospital rotation (precipitating). Her anxiety trait (predisposing) means she lies awake replaying clinical scenarios — a textbook hyperarousal pattern.

    Her GP identified comorbid insomnia and generalised anxiety — present in approximately 40% of insomnia cases. Treatment: parallel CBT-I (sleep-specific cognitions) + CBT for anxiety (general worry patterns).

    Environmental additions: white noise machine (masks hospital-pager-like sounds causing micro-arousals), weighted blanket (deep pressure reduces cortisol, accelerates sleep re-entry after 3 AM anxiety wakings), blue-light glasses (allows clinical note review without melatonin suppression), 10,000-lux lamp (morning light anchor — critical for resetting delayed phase from variable hospital shifts).
    ✓ Month 3: ISI 19 → 7. GAD-7 anxiety score reduced 11 → 5 in parallel.
    🔵 The comorbidity insight: Insomnia and anxiety co-occur in ~40% of cases; insomnia and depression in ~35%. Research consistently shows treating insomnia with CBT-I simultaneously improves mental health outcomes — ISI reductions correlate directly with PHQ-9 (depression) and GAD-7 (anxiety) score reductions. Treating insomnia is, in part, treating the comorbid mental health condition. Source: Riemann et al. (2017) Lancet Neurology.
    Person waking up refreshed in morning sunlight after successful CBT-I insomnia recovery
    The goal of CBT-I — waking refreshed consistently: Bright natural light exposure within 30 minutes of waking is one of the most powerful circadian anchors available. It suppresses melatonin, triggers the appropriate morning cortisol rise, and sets the biological clock that determines when you will feel naturally sleepy that night. After successful CBT-I, this morning feeling — absent for months or years — returns as the default.
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    Book
    Say Good Night to Insomnia CBT-I self help book Gregg Jacobs Harvard
    Gregg D. Jacobs PhD — Harvard Medical School
    Say Good Night to Insomnia: The 6-Week, Drug-Free CBT-I Program — Updated Edition
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    ✅ Your ISI score is a starting point — not a life sentence. Whether you scored subthreshold (8–14) or severe (22–28), insomnia is one of the most treatable conditions in medicine. CBT-I achieves lasting remission in 70–80% of patients — including those with 10+ years of chronic insomnia. The products above support the sleep hygiene layer of CBT-I, but the core treatment is behavioural and cognitive. Use your ISI score to take the right next step: structured self-help for scores under 15 · GP referral for scores 15–21 · urgent sleep medicine evaluation for scores 22 and above.