ISI: Insomnia Severity Index
7-item validated insomnia severity scale. Score 0–28 across four severity bands: no insomnia, subthreshold, moderate clinical, severe. Primary outcome measure in CBT-I trials. Morin et al., 2011.
ISI Score Interpreter
Score indicates clinical insomnia of moderate severity; further assessment and treatment planning are recommended.
7 items, each rated 0–4; total score 0–28. Higher scores indicate greater insomnia severity.
| Total score | Interpretation |
|---|---|
| 22+ | Severe clinical insomniaScore indicates severe insomnia warranting prompt clinical evaluation and evidence-based treatment such as CBT-I. |
| 15–21 | Moderate clinical insomniaScore indicates clinical insomnia of moderate severity; further assessment and treatment planning are recommended. |
| 8–14 | Subthreshold insomniaScore suggests subthreshold insomnia; symptoms may warrant monitoring and preventive intervention. |
| 0–7 | No clinically significant insomniaScore in the range associated with no clinically significant insomnia in validation samples. |
Bastien et al. (2001); Morin et al. (2011). Severity bands per published validation studies. Educational reference only — not a diagnostic tool.
HiBoop automates ISI delivery, scoring, and longitudinal sleep tracking. Monitor insomnia severity alongside depression (PHQ-9) and anxiety (GAD-7) in a single session.
The ISI (Insomnia Severity Index) is a validated 7-item self-report questionnaire for assessing the severity of insomnia symptoms. Developed by Morin (1993) and psychometrically sleep-maintenance difficulty, early morning awakenings, sleep dissatisfaction, functional impairment, noticeability to others, and distress about sleep. Each item is rated on a 0–4 Likert scale; total scores range from 0 to 28. It classifies insomnia into four categories: 0–7 (no clinically significant insomnia), 8–14 (subthreshold insomnia), 15–21 (clinical insomnia, moderate severity), and 22–28 (clinical insomnia, severe). The ISI is widely used as an outcome measure in CBT-I trials and routine insomnia screening. A high ISI score warrants clinical evaluation, it does not constitute a diagnosis. For related tools, see our assessment library and measurement-based care resources.
HiBoop supports automated ISI delivery with integrated scoring and longitudinal sleep quality tracking for insomnia monitoring in mental health and primary care practices.
The Insomnia Severity Index (ISI) is the most widely used brief self-report measure for evaluating insomnia severity in both clinical practice and research. It assesses the current severity of insomnia symptoms over the past two weeks across seven dimensions, producing a total score that maps to four clinical severity bands.
Instructions: Rate each of the following over the past 2 weeks.
All items use a 0–4 scale where 0 = None / Not at all and 4 = Very Severe / Very Much.
Severity of Insomnia Problems
How severe have your insomnia symptoms been in the past 2 weeks?
Sleep Satisfaction
How satisfied / dissatisfied are you with your current sleep pattern?
Daily Functioning
To what extent do you consider your sleep problem to interfere with your daily functioning (e.g., daytime fatigue, concentration, work performance, mood)?
Impact on Quality of Life
How noticeable to others do you think your sleeping problem is in terms of impairing the quality of your life?
Worry / Distress
How worried / distressed are you about your current sleep problem?
ISI Scoring and Interpretation
ISI Item Structure
Rates difficulty falling asleep, staying asleep, and waking too early (0=None to 4=Very Severe each)
Rates satisfaction with current sleep pattern (0=Very Satisfied to 4=Very Dissatisfied)
Rates extent that sleep problem interferes with daily functioning (0=Not at all to 4=Very Much)
How noticeable is the sleep problem to others in terms of quality of life impairment
Degree of worry or distress about the sleep problem (0=Not at all to 4=Very Much)
ISI Psychometric Properties
Excellent Cronbach's alpha across clinical and community samples (Morin et al., 2011)
Widely used as a primary outcome measure in CBT-I randomized controlled trials (Edinger et al., Morin et al.)
Validated in primary insomnia, cancer, chronic pain, depression, PTSD, and general community samples; translated into 40+ languages
Insomnia and Comorbid Mental Health Conditions
Insomnia is highly comorbid with depression, anxiety, and PTSD. In major depressive disorder, insomnia occurs in 60–80% of patients; in PTSD, sleep disturbance is a diagnostic criterion. CBT-I is effective even when insomnia is comorbid with these conditions.
When administering the ISI alongside mood or anxiety measures, document whether sleep difficulties are primary or secondary to determine treatment sequencing.
Documenting ISI results in clinical notes?
ISI total score and severity band belong in the Objective section of your clinical note. See our SOAP notes guide for templates and documentation examples.
Original development: Morin, C. M. (1993). Insomnia: Psychological assessment and management. Guilford Press.
Copyright: The ISI is available for free use in clinical practice and research. Please cite Morin et al. (2011) when using in research contexts.
Frequently Asked Questions
How is the ISI scored?
The ISI contains 7 items, each rated on a 0–4 Likert scale. All item scores are summed to produce a total between 0 and 28. No items are reverse-scored.
What do ISI score ranges mean?
Scores of 0–7 indicate no clinically significant insomnia, 8–14 subthreshold insomnia, 15–21 moderate clinical insomnia, and 22–28 severe clinical insomnia. These bands were established in validation studies by Bastien et al. (2001) and Morin et al. (2011).
Is the ISI self-report or clinician-administered?
The ISI is a self-report questionnaire completed by the patient, typically requiring 5 minutes or less. Versions validated for clinician and significant-other ratings have also been studied, with strong convergence across informants.
Can the ISI diagnose insomnia disorder?
No. The ISI is a screening and outcome measure, not a diagnostic instrument. A high score warrants clinical follow-up; diagnosis requires a clinical interview that considers duration, frequency, daytime impairment, and exclusion of other causes.
References
- 1.Morin CM, Belleville G, Bélanger L, Ivers H. The Insomnia Severity Index: psychometric indicators to detect insomnia cases and evaluate treatment response. Sleep. 2011;34(5):601-608.View source
- 2.Bastien CH, Vallières A, Morin CM. Validation of the Insomnia Severity Index as an outcome measure for insomnia research. Sleep Med. 2001;2(4):297-307.View source
- 3.Gagnon C, Bélanger L, Ivers H, Morin CM. Validation of the Insomnia Severity Index in primary care. J Am Board Fam Med. 2013;26(6):701-10.View source
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The ISI: Insomnia Severity Index qualifies for reimbursement under these CPT codes (US).
Last reviewed: Jun 3, 2026
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