The Insomnia Severity Index (ISI)
What It Measures
The Insomnia Severity Index (ISI) is a brief self-report questionnaire that captures how much trouble someone is having with sleep in the areas of falling asleep, staying asleep, or waking too early. It also measures much that trouble is bothering them and affecting their daytime life. It looks at the past two weeks, giving a snapshot of both how bad the sleep problem feels and how much it's interfering with everyday functioning.
Developed by Bastien, Vallières, and Morin, the ISI has 7 items rated on a 5-point scale (0–4) for a total score of 0–28, with commonly used cutoffs at 8, 15, and 22 marking subthreshold, moderate, and severe insomnia. Occupational therapists and mental health clinicians use it with adults and older adults in mental health, outpatient, and telehealth settings to screen for insomnia and track how treatment is affecting sleep over time.
Further Reading
Additional Notes
The ISI is distributed by Mapi Research Trust on behalf of its copyright holder, Charles M. Morin, PhD. Free for clinical use.
