Does a 10‑week history of insomnia symptoms (difficulty falling asleep three nights per week, 1–2 hour sleep latency, early‑morning awakening, daytime fatigue, and no signs of obstructive sleep apnea) qualify as acute (sub‑acute) insomnia rather than chronic insomnia?

Yes, 10 weeks is less than 3 months, so this patient has acute/subacute insomnia, not chronic insomnia disorder

You are correct—10 weeks does not meet the 3-month duration threshold required for chronic insomnia disorder diagnosis. According to DSM-5 and International Classification of Sleep Disorders criteria, chronic insomnia requires symptoms to be present at least 3 nights per week for at least 3 months 1. Your patient's 10-week history falls short of this diagnostic criterion.

Classification of This Patient's Insomnia

This patient has acute or subacute insomnia (also called short-term insomnia), characterized by:

• Difficulty falling asleep 3 nights/week
• 1-2 hour sleep latency
• Early-morning awakening
• Daytime fatigue
• Duration: 10 weeks (2.5 months)

The symptoms meet frequency criteria (≥3 nights/week) and demonstrate functional impairment (daytime fatigue), but the duration is insufficient for chronic insomnia disorder diagnosis 1, 2.

Clinical Implications of This Distinction

Why This Matters for Treatment

The distinction between acute/subacute and chronic insomnia has significant treatment implications:

For acute/subacute insomnia (your patient):

• Focus on identifying and addressing precipitating factors (stress, life events, medical conditions)
• Sleep hygiene education and brief behavioral interventions are appropriate first steps
• Short-term pharmacotherapy may be considered if symptoms are severe and causing significant distress
• The goal is to prevent progression to chronic insomnia

For chronic insomnia (≥3 months):

• CBT-I becomes the mandatory first-line treatment with strong guideline support 1
• Pharmacotherapy is only added after CBT-I failure, using shared decision-making 1
• The treatment approach is more intensive and structured

Common Pitfall to Avoid

Do not prematurely diagnose chronic insomnia disorder in patients with <3 months of symptoms, as this may lead to:

• Inappropriate treatment escalation
• Unnecessary long-term medication use
• Missing the opportunity to intervene early with simpler approaches
• Failure to identify and treat reversible precipitating factors

Recommended Approach for Your Patient

At 10 weeks, you should:

1. Thoroughly evaluate for precipitating factors: Recent stressors, medication changes, caffeine/alcohol use, shift work, medical conditions
2. Rule out other sleep disorders: You've appropriately excluded obstructive sleep apnea—also consider restless legs syndrome, circadian rhythm disorders
3. Implement sleep hygiene and brief behavioral interventions: Stimulus control, sleep restriction principles, relaxation techniques
4. Consider short-term pharmacotherapy if symptoms are severe and causing significant functional impairment, while simultaneously addressing behavioral factors
5. Schedule follow-up in 2-4 weeks: If symptoms persist to 12 weeks (3 months), the diagnosis converts to chronic insomnia disorder, and CBT-I becomes the evidence-based first-line treatment 1

The 3-month threshold is not arbitrary—it represents the point at which insomnia typically becomes self-perpetuating through maladaptive behaviors and cognitive patterns, requiring more intensive cognitive-behavioral intervention 2, 3.