DSM-5 Insomnia Disorder: Diagnostic Criteria and First-Line Treatment
Diagnostic Criteria
According to DSM-5, chronic insomnia disorder requires symptoms present at least 3 nights per week for at least 3 months, causing clinically significant functional distress or impairment, and not attributable to other sleep, medical, or mental disorders. 1
The core diagnostic features include:
- Dissatisfaction with sleep quantity or quality 1
- Difficulty initiating sleep (prolonged sleep-onset latency) 1
- Difficulty maintaining sleep (frequent or prolonged awakenings) 1
- Early-morning awakening with inability to return to sleep 1
- Clinically significant distress or impairment in functioning (fatigue, poor cognitive function, mood disturbance, interference with personal functioning) 1
Diagnostic Evaluation
The diagnostic procedure must include a clinical interview covering sleep history (sleep habits, environment, work schedules, circadian factors), sleep questionnaires, sleep diaries, assessment of somatic and mental health, and physical examination. 2
- Polysomnography is indicated when other sleep disorders are suspected (periodic limb movement disorder, sleep-related breathing disorders), in treatment-resistant insomnia, for professional at-risk populations, or when substantial sleep state misperception is suspected. 2
- Actigraphy is not recommended for routine insomnia evaluation but may be useful for differential diagnosis. 3
Age-Related Presentation
Older adults more commonly report difficulty maintaining sleep (wake after sleep onset) rather than problems falling asleep (sleep-onset latency). 1
First-Line Treatment
Cognitive behavioral therapy for insomnia (CBT-I) is the mandatory first-line treatment for all adults with chronic insomnia disorder and must be initiated before any medication is considered. 1, 4, 2, 3
This represents a strong recommendation with moderate-to-high-quality evidence across all major guidelines. 1, 4, 2
CBT-I Components and Delivery
CBT-I is a multicomponent intervention combining cognitive therapy about sleep, behavioral strategies (sleep restriction and stimulus control), and sleep-hygiene education. 4
Multiple delivery formats are equally effective:
- In-person individual or group sessions 4
- Telephone-based counseling 4
- Web-based digital modules 4
- Self-help books 4
- Fully automated digital CBT-I programs (such as FDA-authorized SleepioRx) demonstrate sustained effectiveness at 6 months with significant improvements in insomnia severity, response rates, and remission rates. 5
CBT-I Efficacy
CBT-I produces clinically significant improvements including:
- Higher remission rates 4
- Lower insomnia severity 4
- Shorter sleep-onset latency 4
- Reduced wake after sleep onset 4
- Better sleep efficiency 4
In older adults specifically, CBT-I reduces wake after sleep onset and improves sleep efficiency. 4
Alternative Non-Pharmacologic Options
When comprehensive CBT-I is unavailable, brief behavioral therapy for insomnia (BBT), sleep-restriction therapy alone, stimulus-control therapy alone, and relaxation therapy may be used as alternatives. 4
Sleep hygiene as a single-component therapy is not recommended because it provides minimal benefit compared with control conditions. 4
Pharmacologic Therapy (Second-Line)
Pharmacologic treatment should be added only after CBT-I has been unsuccessful, using shared decision-making that discusses benefits, harms, and costs. 1, 4
This represents a weak recommendation with low-quality evidence for long-term medication use. 1
Short-Term Pharmacologic Options (≤ 4 weeks)
For brief use up to 4 weeks, the following agents have evidence support:
- Benzodiazepine receptor agonists (Z-drugs: eszopiclone, zolpidem, zaleplon) improve sleep-onset latency, total sleep time, and reduce wake after sleep onset. 4, 3
- Low-dose sedating antidepressants (particularly doxepin) improve insomnia severity and overall sleep parameters, especially in older adults. 4, 3
- Benzodiazepines are effective for short-term treatment. 2, 3
Longer-Term Pharmacologic Options
Orexin receptor antagonists (suvorexant, lemborexant, daridorexant) may be used for up to 3 months or longer, with moderate-quality evidence showing improved treatment response and sleep outcomes. 4, 3
Prolonged-release melatonin can be used for up to 3 months in patients ≥55 years. 4, 3
Ramelteon does not differ from placebo in the general adult population but reduces sleep-onset latency in older adults, though evidence is low-quality. 4
Not Recommended
The following are not recommended for insomnia treatment:
- Antihistaminergic drugs 3
- Antipsychotics 2, 3
- Fast-release melatonin 3
- Phytotherapeutics 2, 3
- Complementary and alternative treatments (homeopathy, acupuncture) 2
Critical Safety Considerations
Observational studies link hypnotic drugs to serious adverse effects—including dementia, major injuries, and fractures—particularly in older adults. 4
The FDA warns that hypnotics can cause:
- Daytime impairment 4
- "Sleep driving" and other complex sleep behaviors 4
- Behavioral abnormalities 4
- Worsening depression 4
The FDA recommends using lower dosages than those employed in many clinical trials, especially for older adults. 4
Evidence is insufficient to determine the long-term balance of benefits versus harms for pharmacologic insomnia treatments. 4
Discontinuation Protocol
When discontinuing benzodiazepines or Z-drugs, dose reductions should be gradual at 10-25% per week. 6
Multi-component CBT-I, daridorexant, eszopiclone, and melatonin 2 mg prolonged-release facilitate gradual discontinuation within a cross-tapered program. 6
Special Considerations for Older Adults (≥65 years)
CBT-I remains the first-line treatment for older adults, with demonstrated efficacy in this age group. 4
When medication is required in older adults, preferred options include:
- Low-dose doxepin 4
- Prolonged-release melatonin (≥55 years) 4
- Ramelteon 4
- Dual orexin-receptor antagonists 4
Increased caution is warranted for older adults because age-related changes in sleep physiology raise the risk of adverse effects from hypnotic agents. 4