Your Insomnia Severity Index Score

Enter the total you were given to see the band its authors published for it and what it means.

What This Page Does

This page explains an Insomnia Severity Index (ISI) total you already have, usually from a doctor, a therapist or a sleep clinic. It does not include the questionnaire, which is licensed by its author. Enter your total, and optionally an earlier one, to see the published band and how a change compares with what the research found.

About the ISI

Charles Morin and colleagues at Université Laval in Quebec developed the ISI. It has seven questions, each scored 0 to 4, about how hard sleep has been recently, how satisfied you are with it, and how much it affects your days and worries you, for a total of 0 to 28. Bastien, Vallières and Morin validated it as a research outcome measure in Sleep Medicine in 2001.

In 2011, Morin and colleagues tested it in 959 people from the community and 245 people from a clinical sample, reporting excellent internal consistency (Cronbach's alpha of 0.90 and 0.91) and the cutoffs below.

The Published Bands

A total of 0 to 7 is absence of insomnia.
A total of 8 to 14 is sub-threshold insomnia.
A total of 15 to 21 is moderate insomnia.
A total of 22 to 28 is severe insomnia.

These are the ranges Morin and colleagues give in Sleep (2011). In their community sample, a total of 10 or more was the best single cutoff for finding people with insomnia, with 86.1% sensitivity and 87.7% specificity. A total of 15 or more, or 10 or more with symptoms that bother you, is worth discussing with your doctor.

Insomnia, CPAP and Treatment

Insomnia and obstructive sleep apnea often occur together. A 2019 meta-analysis of 37 studies (Zhang and colleagues, Sleep Medicine Reviews) found that 38% of people with obstructive sleep apnea met criteria for insomnia, and a 2019 review by Sweetman, Lack and Bastien noted that insomnia symptoms tend to lower CPAP use. The American College of Physicians recommends cognitive behavioral therapy for insomnia (CBT-I) as the first treatment for chronic insomnia in adults (Qaseem and colleagues, 2016). If you use CPAP and still sleep poorly, your machine's data can show whether short or broken nights line up with how you feel; our guide to being still tired on CPAP covers the other usual reasons.

Getting the Questionnaire

The ISI is distributed under license by Mapi Research Trust on behalf of Dr. Morin, so we do not reprint it. Ask your doctor, therapist or sleep clinic for it. For a free, well-validated insomnia questionnaire you can take right here, try the Sleep Condition Indicator.

Frequently Asked Questions

What do Insomnia Severity Index scores mean?

ISI totals run from 0 to 28. Its authors interpret 0 to 7 as absence of insomnia, 8 to 14 as sub-threshold insomnia, 15 to 21 as moderate insomnia and 22 to 28 as severe insomnia. In a large community study, 10 or more was the best single cutoff for finding people with insomnia.

Can I take the Insomnia Severity Index here?

No. The ISI is licensed by its author through Mapi Research Trust, and we do not reprint it. Your doctor, therapist or sleep clinic can give you the official version. For a free insomnia questionnaire you can take on this site, try the Sleep Condition Indicator.

How much does an ISI score need to drop to show improvement?

In the 2011 validation study by Morin and colleagues, a drop of about 8.4 points went with moderate improvement after treatment, as judged by an independent assessor. A total below 8 after treatment falls in the range the authors describe as absence of insomnia.

Can I have insomnia and sleep apnea at the same time?

Yes. A 2019 meta-analysis of 37 studies found that 38% of people with obstructive sleep apnea met criteria for insomnia, and a 2019 review noted that insomnia symptoms tend to lower CPAP use. Treating one does not treat the other, so both are worth raising with your doctor.