Insomnia Severity Index Test

The ISI is a validated 7-item self-report questionnaire developed by Dr. Charles Morin to measure the nature, severity, and impact of insomnia. It is the most widely used insomnia screening tool in clinical research and sleep medicine practice worldwide.

Yes. The ISI is considered a psychological screening instrument for insomnia disorder. It measures the cognitive, emotional, and functional dimensions of insomnia — not just sleep duration — making it one of the most clinically accurate self-report tools available.

A score of 15–21 indicates moderate clinical insomnia. A score of 22–28 indicates severe clinical insomnia. Both levels warrant evidence-based treatment, with CBT-I (Cognitive Behavioral Therapy for Insomnia) as the first-line recommendation from the AASM.

Both tools are based on the ISI framework. This dedicated ISI test follows the original 7-question structure exactly and presents clinical severity bands with detailed treatment pathways. It is optimised for people who want a more clinical, research-grade screening result.

No. This is a screening tool, not a diagnostic instrument. A formal diagnosis of insomnia disorder requires a clinical evaluation by a physician or sleep specialist who can rule out other causes (sleep apnea, restless legs syndrome, depression, medication side effects).

Every 2–4 weeks if you are actively working on improving your sleep. Monthly for ongoing monitoring. The value of the ISI is in tracking trends over time rather than a single score.

CBT-I (Cognitive Behavioral Therapy for Insomnia) is a structured 6–8 session psychological treatment that addresses the thoughts and behaviors perpetuating insomnia. It is more effective than sleeping pills long-term, with 70–80% of patients achieving sustained remission at 12-month follow-up. It is the official first-line treatment per the American College of Physicians.

Substantially. Chronic insomnia roughly doubles the lifetime risk of major depressive disorder and significantly increases risk of generalized anxiety disorder, PTSD vulnerability, and bipolar episode frequency. The relationship is bidirectional — treating insomnia directly improves mental health outcomes independent of other interventions.