Insomnia: Causes, Symptoms, and Evidence-Based Treatments

Insomnia disorder (DSM-5/ICSD-3): dissatisfaction with sleep quantity/quality despite adequate opportunity, occurring ≥3 nights/week for ≥3 months, causing daytime impairment.

Etiology (3P Model)

• Predisposing: Genetic, hyperarousal trait, female sex, age.
• Precipitating: Stress, medical illness, medications, shift work, bereavement.
• Perpetuating: Maladaptive behaviors (time in bed extension, napping), cognitive arousal (worry about sleep), conditioned arousal (bed = wakefulness).

Clinical Features

Sleep onset latency >30 min, wake after sleep onset >30 min, early morning awakening, non-restorative sleep → daytime fatigue, concentration deficits, mood disturbance, reduced performance.

First-Line Treatment: CBT-I

Cognitive Behavioral Therapy for Insomnia (6–8 sessions) outperforms medications long-term with no side effects. Components:

• Stimulus Control: Bed only for sleep/sex; leave bed if awake >20 min.
• Sleep Restriction: Match time in bed to actual sleep time; gradually extend.
• Cognitive Restructuring: Challenge catastrophic sleep beliefs.
• Sleep Hygiene: Regular schedule, dark/cool/quiet room, limit caffeine/alcohol/screens.
• Relaxation: Progressive muscle relaxation, diaphragmatic breathing, mindfulness.

Pharmacotherapy (Adjunct/Short-Term)

• Non-benzodiazepine receptor agonists (zolpidem, eszopiclone, zaleplon)
• Orexin antagonists (suvorexant, lemborexant, daridorexant)
• Melatonin receptor agonist (ramelteon)
• Low-dose doxepin (3–6 mg) for maintenance insomnia
• Avoid long-term benzodiazepines (dependence, tolerance, falls, dementia risk).

When to Refer

Persistent insomnia despite CBT-I, suspected sleep apnea (snoring, witnessed apneas), restless legs, circadian rhythm disorders, or comorbid psychiatric conditions.