A Score of 15 Puts You in the “Moderate Clinical Insomnia” Category
You scored 15 on the Insomnia Severity Index. That’s not great news, but it’s not catastrophic either. It means your sleep problems have crossed from “annoying but manageable” into “clinically significant and worth treating.” And the good news is that moderate insomnia responds really well to evidence-based treatment.
The ISI is a 7-item questionnaire scoring 0–28 that measures insomnia severity across three domains: difficulty falling asleep, difficulty staying asleep, and early morning awakening — plus their impact on your daily functioning and how distressed you are about them.
Where 15 Falls on the Scale
- 0–7: No clinically significant insomnia
- 8–14: Subthreshold insomnia (symptoms present but below clinical levels)
- 15–21: Moderate clinical insomnia
- 22–28: Severe clinical insomnia
At 15, you’re at the entry point of moderate insomnia. Your sleep problems are real, they’re affecting your life, and they meet clinical thresholds — but you haven’t reached the severe range where sleep is essentially a nightly crisis.
What a Score of 15 Typically Looks Like Day-to-Day
People scoring around 15 usually describe a pattern like this: falling asleep takes 30–60 minutes most nights, or they wake up in the middle of the night and can’t fall back asleep for an hour or more. Daytime fatigue is consistent. Concentration suffers. Irritability is noticeable — your partner, coworkers, or kids have probably mentioned it. You’re not a total wreck, but you’re operating at maybe 60–70% of your capacity and you know it.
Rachel, a 38-year-old project manager, described her experience at this score level: “I could usually fall asleep okay, but I’d wake up at 3 a.m. like clockwork. Wide awake. Mind racing. I’d finally drift off again around 5, and then the alarm goes off at 6:30. By Thursday each week, I was running on fumes.”
The Gold Standard Treatment: CBT-I
Cognitive Behavioral Therapy for Insomnia (CBT-I) is the first-line treatment recommended by every major medical organization — the American Academy of Sleep Medicine, the American College of Physicians, and the European Sleep Research Society. It outperforms sleeping pills in the long run and doesn’t carry dependency risk.
CBT-I typically involves 4–8 sessions and includes:
- Sleep restriction: Sounds counterintuitive, but temporarily limiting your time in bed increases sleep drive and consolidates sleep. If you’re lying in bed 9 hours but only sleeping 5.5, you restrict to 6 hours in bed — then gradually expand as sleep efficiency improves.
- Stimulus control: Bed is for sleep and sex only. If you’re awake more than 15–20 minutes, you get up and go to another room until drowsy. This breaks the association between bed and wakefulness.
- Cognitive restructuring: Addressing the catastrophic thoughts about sleep (“If I don’t fall asleep in the next 30 minutes, tomorrow will be a disaster”) that actually perpetuate insomnia.
- Sleep hygiene: Consistent wake time, cool dark bedroom, no screens before bed, caffeine cutoff. These alone usually don’t fix clinical insomnia, but they support the other interventions.
About 70–80% of people with moderate insomnia improve significantly with CBT-I. And unlike medication, the benefits persist after treatment ends.
What About Sleeping Pills?
They work in the short term but create problems long-term. Benzodiazepines (Ativan, Valium) and Z-drugs (Ambien, Lunesta) cause tolerance (you need more), dependence (you can’t sleep without them), rebound insomnia when stopped, and impaired sleep architecture (they suppress deep sleep and REM). For acute insomnia lasting a few weeks, a short course can bridge the gap. For chronic insomnia like what a score of 15 usually represents, they’re the wrong tool.
Melatonin can help if your issue is a circadian rhythm problem (you want to sleep but your clock is set wrong), but it’s minimally effective for classic insomnia. Low dose (0.5–1 mg) is better than the 5–10 mg products filling pharmacy shelves.
When Your ISI Score Signals Something Else
Insomnia doesn’t exist in a vacuum. At a score of 15, it’s worth screening for conditions that commonly cause or worsen insomnia:
- Depression and anxiety: Our DASS-21 can screen for all three simultaneously. About 40% of people with chronic insomnia have a co-occurring mood or anxiety disorder.
- Sleep apnea: Especially if you snore, gasp during sleep, or feel unrefreshed despite adequate sleep hours. Apnea causes frequent micro-awakenings that register as insomnia.
- Restless legs syndrome: Uncomfortable sensations in the legs that worsen at rest and are relieved by movement. A common and underdiagnosed cause of difficulty falling asleep.
Frequently Asked Questions
Should I see a sleep specialist for a score of 15?
It’s a good idea if basic sleep hygiene improvements haven’t helped after 4–6 weeks. A sleep specialist can offer CBT-I, rule out other sleep disorders, and provide targeted treatment. Many CBT-I programs are now available online (like Somryst/Pear Therapeutics or CBT-I Coach) if in-person access is limited.
How quickly can my ISI score improve with treatment?
Most people see meaningful improvement within 4–6 weeks of starting CBT-I. A clinically significant improvement is defined as a reduction of 7 or more points on the ISI. So a score of 15 could potentially drop to 8 (subthreshold) or lower within 6–8 weeks of treatment.
Is a score of 15 enough to get time off work?
The ISI score alone doesn’t determine that, but moderate clinical insomnia with documented functional impairment could support a short-term leave or workplace accommodation request through your healthcare provider. The key is documenting how the insomnia affects your specific job performance and safety.
