Insomnia Severity Index: ISI Score Guide & Meaning
Learn what the Insomnia Severity Index measures, how the standard 0–28 score is interpreted, where to request authorized access, and why one score cannot diagnose chronic insomnia or select a treatment.
The Insomnia Severity Index (ISI) is a seven-item self-report measure of perceived insomnia severity and impact. Each item is scored 0–4, producing a total from 0 to 28. Published interpretation bands are commonly 0–7, 8–14, 15–21 and 22–28. These bands describe symptom severity; they do not diagnose chronic insomnia by themselves.
Use an Authorized Insomnia Severity Index
The ISI is distributed by Mapi Research Trust on behalf of its copyright holder, Prof. Charles Morin. SmartSleepCalc does not reproduce, paraphrase, translate, or electronically administer the seven ISI questions on this page.
Conditions of use depend on the intended setting and implementation. Electronic versions and other adaptations can also have licensing requirements. If SmartSleepCalc later obtains documented permission for this exact use, the authorized wording, response options and scoring should be used exactly as licensed.
Open official ISI information →What Do ISI Scores Mean?
The standard ISI total ranges from 0 to 28. The bands below are conventional severity descriptions used in the literature. They are not stand-alone diagnoses or automatic treatment rules.
| Total score | Conventional description | Important limitation |
|---|---|---|
| 0–7 | No clinically significant insomnia | A low score does not rule out another sleep problem or persistent symptoms needing evaluation. |
| 8–14 | Subthreshold insomnia | Describes symptom burden; it does not predict inevitable progression. |
| 15–21 | Clinical insomnia — moderate severity | This is a severity label, not a diagnosis by itself. |
| 22–28 | Clinical insomnia — severe | Higher symptom burden deserves attention, but treatment is not selected from the number alone. |
Insomnia Pattern Context Checker
This original tool does not reproduce ISI questions, does not produce an ISI score, and is not a validated insomnia test. It simply organizes context that can help decide what deserves attention next.
What the ISI Can—and Cannot—Tell You
The ISI is a brief self-report measure of insomnia symptoms and their impact.
When used appropriately and consistently, it can be one outcome measure over time.
Diagnosis also considers persistence, frequency, adequate sleep opportunity, daytime consequences, and other explanations.
Sleep apnea, circadian misalignment, restless legs, pain, mood disorders, medications, substances, and other issues may contribute.
A score does not determine which drug, supplement, or dose is appropriate.
Sleep restriction therapy is a structured behavioral treatment with safety considerations and should not be auto-generated from a score.
CBT-I Is Strongly Recommended for Chronic Insomnia
AASM recommends multicomponent cognitive behavioral therapy for insomnia (CBT-I) for adults with chronic insomnia disorder. It commonly combines cognitive strategies, education about sleep regulation, stimulus control, sleep restriction therapy, and often other behavioral components. The guideline describes treatment as typically delivered over about 4–8 sessions, but the schedule and response vary.
AASM gives multicomponent CBT-I a strong recommendation for chronic insomnia disorder in adults.
A guideline-supported treatment does not mean everyone improves in the same number of days or weeks.
General sleep-hygiene advice is not equivalent to a structured CBT-I program.
For a broader evidence-based overview, see SmartSleepCalc’s insomnia guide.
What to Do Next
Duration, frequency, daytime impact, sleep opportunity, and competing explanations matter.
Loud snoring, gasping, witnessed breathing pauses, severe sleepiness, restless legs, shift work, or a strongly delayed schedule may point to another or additional issue.
Ongoing sleep difficulty that affects daily function deserves clinical context regardless of the exact severity band.
CBT-I is the main evidence-based behavioral treatment recommended by major guidelines.
Medication or supplement decisions require individual clinical context and interaction review.
ISI FAQs
Does an ISI score diagnose insomnia?
No. The ISI measures perceived insomnia severity and impact. Diagnosis requires clinical criteria and context beyond the score.
Why doesn’t SmartSleepCalc display the seven ISI questions?
The ISI is copyrighted and distributed by Mapi Research Trust on behalf of Prof. Charles Morin. SmartSleepCalc does not have documented permission in the supplied evidence for commercial electronic administration, so this page does not reproduce the instrument.
What do the common ISI bands mean?
Published interpretation commonly uses 0–7, 8–14, 15–21 and 22–28 as increasing severity bands. They describe symptom burden, not a stand-alone diagnosis.
How long does CBT-I take?
AASM describes multicomponent CBT-I as typically delivered over about 4–8 sessions. Session spacing and individual response vary, so this page does not promise a fixed recovery timeline.
Should I change medication or take a sleep aid based on my score?
No. An ISI score does not identify which medication, supplement, or dose is appropriate. Review persistent insomnia and repeated sleep-aid use with a healthcare professional or pharmacist.
Sources
- Mapi Research Trust / ePROVIDE. Official ISI information, copyright ownership, distribution, and conditions-of-use contact. Official ISI page
- Mapi Research Trust. Questionnaire licensing and COA copyright guidance. Licensing information
- Bastien CH, Vallières A, Morin CM. Validation of the Insomnia Severity Index as an outcome measure for insomnia research. Sleep Medicine. 2001. PubMed
- Edinger JD, et al. Behavioral and psychological treatments for chronic insomnia disorder in adults: AASM clinical practice guideline. J Clin Sleep Med. 2021. Full text