Primary Insomnia (Chronic Insomnia Disorder)

What primary insomnia is

Older systems divided insomnia into "primary" (no other cause) and "secondary" (caused by another condition). Current classifications (DSM-5-TR and the International Classification of Sleep Disorders) use a single diagnosis, insomnia disorder, because insomnia often persists and needs its own treatment even when another condition is present. "Primary insomnia" is still widely used to describe insomnia that is the main problem. For the broader overview, see insomnia.

Diagnostic criteria

• Difficulty falling asleep, staying asleep or waking too early
• At least 3 nights a week, for at least 3 months
• Despite adequate opportunity to sleep
• Causing distress or daytime problems: tiredness, poor concentration, mood changes, errors
• Not better explained by another sleep disorder, substance or condition

Why insomnia becomes chronic

The "3P model" explains how insomnia develops and persists:

The perpetuating factors keep insomnia going long after the original trigger has passed. The bed becomes linked with wakefulness and frustration (conditioned arousal), and anxiety about sleep makes it harder to sleep.

Symptoms

• Lying awake for 30 minutes or more before falling asleep
• Waking during the night and struggling to get back to sleep
• Waking early and being unable to return to sleep
• Feeling unrefreshed
• Daytime fatigue, poor concentration and memory
• Irritability, low mood or anxiety
• Worry about sleep, especially in the evening
• Often feeling wide awake when going to bed, despite being tired during the day

Conditions to rule out

• Sleep apnea: snoring, gasping, daytime sleepiness
• Restless legs syndrome: urge to move legs in the evening
• Delayed sleep phase disorder: sleeping well but at a later time than desired
• Depression and anxiety disorders
• Chronic pain, reflux, nighttime urination, hot flashes, thyroid disease
• Medicines and substances: caffeine, alcohol, nicotine, stimulants, some antidepressants, steroids, decongestants

Diagnosis

Diagnosis is based on history. A doctor may ask you to keep a sleep diary for 1 to 2 weeks, recording bedtime, time to fall asleep, night wakings, wake time and naps. Questionnaires such as the Insomnia Severity Index help track severity. Sleep studies are not needed for insomnia itself but are used if sleep apnea or another sleep disorder is suspected.

Treatment

Cognitive behavioral therapy for insomnia (CBT-I)

CBT-I is recommended as first-line treatment by the American College of Physicians and the American Academy of Sleep Medicine. It usually involves 4 to 8 sessions and includes:

• Stimulus control: go to bed only when sleepy, use the bed only for sleep and sex, and get up if unable to sleep after about 20 minutes, returning when sleepy
• Sleep restriction: temporarily limiting time in bed to match actual sleep time, which builds sleep drive, then gradually extending it
• Cognitive therapy: challenging unhelpful beliefs such as "I can't function without 8 hours"
• Relaxation training: breathing, progressive muscle relaxation
• Sleep hygiene education

CBT-I works for most people, including older adults and those with other health conditions, and its benefits last after treatment ends. Digital CBT-I programs are effective options when therapists are not available.

Medicines

Medicines may be considered when CBT-I is not available or not enough, ideally for short periods and with regular review:

• Orexin receptor antagonists (suvorexant, lemborexant, daridorexant)
• "Z-drugs" (zolpidem, eszopiclone, zaleplon)
• Low-dose doxepin for sleep maintenance
• Ramelteon for sleep onset

Benzodiazepines are generally avoided due to dependence, falls and memory effects, especially in older adults. Over-the-counter sleep aids containing antihistamines (diphenhydramine, doxylamine) are not recommended for chronic insomnia and can cause confusion in older people. Melatonin has limited benefit for chronic insomnia except in circadian rhythm problems.

Sleep habits that support treatment

• Keep a fixed wake-up time every day, including weekends
• Avoid caffeine after midday and limit alcohol, which fragments sleep
• Get daylight in the morning and stay active during the day
• Avoid long daytime naps
• Wind down for an hour before bed, away from work and bright screens
• Keep the bedroom cool, dark and quiet
• Do not clock-watch at night

Outlook

Chronic insomnia can last for years without treatment, but CBT-I produces meaningful improvement for most people within weeks, and the gains are durable. Treating insomnia also improves mood and reduces the risk of depression.

Frequently asked questions

What is primary insomnia?

Primary insomnia is long-term difficulty falling or staying asleep, at least 3 nights a week for 3 months, that is not explained by another medical, mental health or sleep disorder. It is now diagnosed as chronic insomnia disorder.

What causes primary insomnia?

It usually starts with a trigger such as stress and continues because of hyperarousal, worry about sleep, irregular schedules, napping and spending long periods awake in bed, which teach the brain to associate bed with wakefulness.

What is the best treatment for chronic insomnia?

Cognitive behavioral therapy for insomnia (CBT-I) is the recommended first-line treatment. It combines stimulus control, sleep restriction, cognitive techniques and relaxation, and its benefits last longer than sleeping pills.

Are sleeping pills safe for long-term insomnia?

Sleeping pills can help short term but carry risks such as dependence, next-day drowsiness, falls and memory problems, especially in older adults. Long-term use should be discussed with a doctor, and CBT-I is preferred.

How long does it take for CBT-I to work?

Many people notice improvement within 2 to 4 weeks, with greater gains by the end of a 6 to 8 week program. Sleep may feel worse briefly during sleep restriction before it improves.