Answer 7 validated questions about your sleep over the past 2 weeks. Get a clinical severity score, component breakdown, and personalized guidance in under 2 minutes.
Rate each item based on the past 2 weeks.
Difficulty falling asleep
Difficulty staying asleep
Problem waking up too early
How satisfied/dissatisfied are you with your current sleep pattern?
How noticeable to others is your sleep problem in terms of impairing your quality of life?
How worried/distressed are you about your current sleep problem?
To what extent does your sleep problem interfere with daily functioning? (e.g., fatigue, mood, concentration, memory)
Cutoffs from Morin et al. (2011). Sensitivity 86.1%, specificity 87.7% at threshold of 10.
The Insomnia Severity Index was developed by Dr. Charles Morin at Laval University in 1993 as a brief, reliable measure of insomnia severity. Unlike sleep diaries, which require 1-2 weeks of tracking, the ISI captures perceived severity in a single 2-minute assessment.
The definitive 2011 validation by Morin et al. in a community sample of 1,670 adults showed Cronbach's alpha of 0.91 and sensitivity of 86.1% / specificity of 87.7% at a cutoff of 10. The ISI is now one of the most widely used insomnia outcome measures in clinical trials worldwide.
The Insomnia Severity Index (ISI) is a validated, self-report questionnaire developed by Dr. Charles Morin at Université Laval in 1993. It was designed as a brief, reliable clinical measure of perceived insomnia severity that could be administered repeatedly to track treatment response. The ISI consists of seven items targeting the subjective symptoms and consequences of insomnia: difficulty falling asleep, difficulty staying asleep, early morning awakening, sleep dissatisfaction, interference with daytime functioning, noticeability of sleep problems to others, and distress caused by the sleep problem.
Each item is rated on a 0–4 Likert scale, yielding a total score between 0 and 28. The ISI was formally validated by Bastien, Vallières, & Morin (2001) in Sleep Medicine, and a landmark 2011 community validation by Morin et al. in a sample of 1,670 adults confirmed Cronbach’s alpha of 0.91, with sensitivity of 86.1% and specificity of 87.7% at a clinical cutoff of 10. The ISI is now one of the most widely used insomnia outcome measures in clinical trials and sleep medicine practice worldwide.
Your ISI total score maps to four clinical severity categories. A score of 0–7 indicates no clinically significant insomnia — your sleep appears healthy and no intervention is needed beyond maintaining good sleep hygiene. A score of 8–14 represents subthreshold (mild) insomnia, where sleep difficulties are present but may not yet meet full diagnostic criteria; targeted sleep hygiene improvements and consistent scheduling often help at this stage.
A score of 15–21 indicates moderate clinical insomnia, where CBT-I (Cognitive Behavioral Therapy for Insomnia) is the recommended first-line treatment per the American Academy of Sleep Medicine. A score of 22–28 represents severe clinical insomnia that requires prompt clinical attention — CBT-I and potentially short-term pharmacotherapy should be discussed with a sleep medicine specialist. These thresholds were established in the 2001 validation study and confirmed in the 2011 community sample, and are used in clinical trials to define treatment response (typically a reduction of 8+ points or crossing below the clinical threshold of 10).
No. The ISI is a subjective self-report screening tool that measures your perception of insomnia severity over the past two weeks. It captures how you experience your sleep problem — how difficult it is to fall or stay asleep, how dissatisfied you are, and how much it affects your daytime life. A polysomnography (PSG) sleep study, by contrast, is an objective diagnostic test that measures brain waves, eye movements, muscle activity, heart rhythm, blood oxygen, and airflow during an overnight stay in a sleep laboratory.
The ISI and PSG answer different clinical questions. PSG is essential for diagnosing conditions like obstructive sleep apnea, narcolepsy, and periodic limb movement disorder — conditions where objective measurement of physiological events during sleep is required. The ISI is designed to quantify the subjective burden of insomnia, which correlates only modestly with objective sleep measures because insomnia is fundamentally a disorder of perceived sleep quality and hyperarousal. Many patients with clinical insomnia show relatively normal sleep architecture on PSG, while their subjective distress and daytime impairment are very real. Both tools have distinct and complementary roles in sleep medicine.
Cognitive Behavioral Therapy for Insomnia (CBT-I) is a structured, evidence-based psychological treatment that targets the thoughts and behaviors that perpetuate chronic insomnia. It typically involves 4–8 sessions and includes several core components: sleep restriction therapy (temporarily limiting time in bed to match actual sleep time, building sleep pressure), stimulus control (re-associating the bed with sleep by leaving bed when awake), cognitive restructuring (addressing catastrophic beliefs about sleep consequences), sleep hygiene education, and relaxation training.
The American Academy of Sleep Medicine (AASM) recommends CBT-I as the first-line treatment for chronic insomnia disorder in adults, ahead of pharmacotherapy. Multiple randomized controlled trials and meta-analyses have demonstrated that CBT-I produces durable improvements in sleep onset latency, wake after sleep onset, sleep efficiency, and ISI scores — with effects that persist long after treatment ends, unlike sleep medications whose benefits cease upon discontinuation. CBT-I is available through trained psychologists, sleep medicine clinics, and increasingly through validated digital programs (dCBT-I) that make it accessible to patients without local specialists.
If you are actively undergoing treatment for insomnia (whether CBT-I, medication, or behavioral changes), retaking the ISI every 2–4 weeks is the recommended cadence used in clinical trials. This interval captures meaningful change while accounting for the natural week-to-week variability in sleep patterns. A clinically significant improvement is typically defined as a reduction of 8 or more points on the ISI, or a score that drops below the clinical threshold of 10.
For maintenance monitoring after treatment, monthly ISI assessments for the first 3–6 months help catch early signs of relapse. After that, quarterly or event-triggered reassessment (e.g., after a major life change, new medication, or return of symptoms) is sufficient. The ISI’s two-week recall window makes it ideal for repeated measurement — unlike tools with a one-month window, it is sensitive enough to detect changes within a single treatment cycle. Tracking your scores over time also provides valuable data to share with your clinician and can reinforce motivation by making progress visible.
Yes — insomnia frequently co-occurs with and can be a symptom of other medical and psychiatric conditions. Obstructive sleep apnea (OSA) can present as difficulty maintaining sleep, with frequent arousals that the patient may not consciously register. Depression and anxiety disorders are among the most common comorbidities: up to 80% of patients with major depression report insomnia, and insomnia itself is a significant risk factor for developing depression. Chronic pain conditions (arthritis, fibromyalgia, neuropathy) directly disrupt sleep architecture and increase arousal.
Medications can also cause or worsen insomnia — common culprits include SSRIs, beta-blockers, corticosteroids, stimulant medications, and some asthma drugs. Hormonal changes during menopause (hot flashes, night sweats) are a frequent trigger for new-onset insomnia in women. Restless legs syndrome and circadian rhythm disorders (such as delayed sleep-wake phase disorder) can mimic insomnia symptoms. If your ISI score is elevated and does not improve with standard sleep hygiene and behavioral changes over 4–6 weeks, a comprehensive medical evaluation to identify underlying contributors is strongly recommended before assuming primary insomnia.