ISI Scoring and Clinical Use

The Insomnia Severity Index (ISI) was developed by Charles M. Morin in 1993 as a brief, reliable, and valid measure of insomnia severity. It assesses seven dimensions of insomnia over the past two weeks.

How the ISI is scored:

• The ISI consists of 7 items, each rated on a 0–4 Likert scale
• Total scores range from 0 to 28
• Higher scores indicate greater insomnia severity

Severity levels:

• 0–7: No clinically significant insomnia — Your sleep appears to be within normal range. No intervention needed, though continuing good sleep habits is always beneficial.
• 8–14: Subthreshold insomnia — You may be experiencing some sleep difficulties that are below clinical thresholds. Monitoring and sleep hygiene improvements may be sufficient.
• 15–21: Moderate clinical insomnia (moderate severity) — Your insomnia is clinically significant. Treatment is recommended, particularly Cognitive Behavioral Therapy for Insomnia (CBT-I).
• 22–28: Severe clinical insomnia (severe) — Your insomnia is severe and likely causing substantial daytime impairment. Professional treatment is strongly recommended.

Clinical use and tracking progress: The ISI is widely used in clinical trials and sleep medicine practice to assess insomnia severity and track treatment response. A reduction of 8 or more points is generally considered a clinically meaningful improvement. The ISI is recommended by the American Academy of Sleep Medicine as a patient-reported outcome measure for insomnia research and clinical practice.

Psychometric properties: The ISI has demonstrated excellent internal consistency (Cronbach’s alpha = 0.74–0.91), good test-retest reliability, and strong convergent validity with sleep diary measures and polysomnography findings.

Evidence-Based Treatment Options

Insomnia is one of the most treatable sleep disorders, with several evidence-based options available:

Cognitive Behavioral Therapy for Insomnia (CBT-I) — Gold Standard:

• CBT-I is recommended as the first-line treatment for chronic insomnia by the American College of Physicians, the American Academy of Sleep Medicine, and the European Sleep Research Society
• It typically involves 4–8 sessions with a trained therapist and addresses the thoughts and behaviors that perpetuate insomnia
• Components include sleep restriction therapy, stimulus control, cognitive restructuring, relaxation training, and sleep hygiene education
• Produces durable improvements that persist long after treatment ends, unlike medication
• Available in-person, via telehealth, and through digital/app-based programs (e.g., CBT-I Coach, Somryst/Pear Therapeutics)

Sleep Restriction Therapy:

• A core component of CBT-I that limits time in bed to match actual sleep time
• Creates mild sleep deprivation that builds sleep drive and consolidates sleep
• Gradually increases time in bed as sleep efficiency improves (target: 85%+ efficiency)
• Can be challenging initially but is one of the most effective single-component interventions

Stimulus Control Therapy:

• Strengthens the association between bed/bedroom and sleep
• Rules include: go to bed only when sleepy, leave bed if awake for 15–20 minutes, use bed only for sleep and intimacy, maintain a fixed wake time, avoid napping
• Developed by Richard Bootzin in 1972 and supported by decades of research

Medication options (always under medical supervision):

• Melatonin receptor agonists (e.g., ramelteon) — target the circadian system with low abuse potential
• Orexin receptor antagonists (e.g., suvorexant, lemborexant) — newer medications that block wakefulness-promoting signals
• Short-acting benzodiazepine receptor agonists (e.g., zolpidem, eszopiclone) — effective short-term but risk of dependence
• Low-dose doxepin — FDA-approved for sleep maintenance insomnia
• Over-the-counter melatonin — may help with circadian timing issues; limited evidence for primary insomnia

Important note: Medication is generally recommended only for short-term use or as an adjunct to CBT-I. Long-term use of sleep medications can lead to tolerance, dependence, and rebound insomnia. CBT-I provides more lasting benefits without these risks.

10 Evidence-Based Sleep Hygiene Tips

Sleep hygiene alone is rarely sufficient to treat clinical insomnia, but these practices form the foundation of healthy sleep and complement other treatments:

• 1. Maintain a consistent sleep schedule: Go to bed and wake up at the same time every day, including weekends. This reinforces your circadian rhythm and improves sleep quality over time. Irregular schedules are one of the most common contributors to insomnia.
• 2. Create an optimal sleep environment: Keep your bedroom cool (65–68°F / 18–20°C), dark, and quiet. Use blackout curtains, earplugs, or a white noise machine as needed. Invest in a comfortable mattress and pillows.
• 3. Limit screen time before bed: Avoid phones, tablets, computers, and television for at least 30–60 minutes before bedtime. Blue light from screens suppresses melatonin production and delays sleep onset. Use night mode or blue-light-blocking glasses if screens are unavoidable.
• 4. Avoid caffeine after noon: Caffeine has a half-life of 5–7 hours, meaning half is still in your system many hours after consumption. Avoid coffee, tea, energy drinks, and chocolate in the afternoon and evening. Be aware of hidden caffeine in medications and supplements.
• 5. Limit alcohol consumption: Although alcohol may help you fall asleep faster, it disrupts sleep architecture, reduces REM sleep, and increases nighttime awakenings. Avoid alcohol within 3–4 hours of bedtime.
• 6. Exercise regularly, but not too late: Regular physical activity improves sleep quality and duration. Aim for at least 150 minutes of moderate exercise per week. Complete vigorous exercise at least 3–4 hours before bedtime, as exercising too close to sleep can be stimulating.
• 7. Develop a relaxing bedtime routine: Engage in calming activities for 30–60 minutes before bed, such as reading (not on a screen), gentle stretching, meditation, deep breathing, or a warm bath. A consistent routine signals your body that it is time to wind down.
• 8. Avoid large meals and excessive fluids before bed: Eating a heavy meal within 2–3 hours of bedtime can cause discomfort, acid reflux, and disrupted sleep. Limit fluid intake in the evening to reduce nighttime bathroom trips.
• 9. Get natural light exposure during the day: Exposure to bright, natural light during the morning and daytime helps regulate your circadian clock and promotes better sleep at night. Aim for at least 30 minutes of outdoor light, especially in the morning.
• 10. Reserve the bed for sleep and intimacy only: Avoid working, eating, watching TV, or scrolling your phone in bed. This strengthens the mental association between your bed and sleep, making it easier to fall asleep when you get into bed.