Def: difficulty falling or maintaining sleep for atleast 3 times a week for atleast 3 months.
Provided other sleep disorders are ruled out.
Prevelance; atleast 6-10% of adults, mostly women

Subtypes of Chronic Insomnia
1. Psychophysiological – racing thoughts, heightened arousals, anxiety
2. Paradoxical Insomnia – perception of not sleeping, when all objective data says otherwise
3. Insomnia from poor sleep hygiene
4. Insomnia due to medical disorders
5. Insomnia due to underlying mood disorders / psych
6. Insomnia due to medications
7. insomnia due to substance abuse
8. In children – behaviroal insomnia of childhood – futher classified as association type or limited setting

Risk factors
females, menopause, family history, past history of insomnia, anxiety

Consequences of Insomnia
Short term: fatigue, mood disturbances, annoyance to noise/light, irritability, poor quality of life, social withdrawal, reduced cognitive performance
Long term: worsening anxiety and depression, risk factor for psychological comorbidities like Bipolar disorder and Schizophrenia, alcohol abuse, hypertension, insulin resistance and diabetes, dementia
Economic impact: reduced productivity, late for work, burden on healthcare system (63-90 billion USD per year)

Diagnosis
based on clinic history, ruling out medical / sleep disorders
Sometimes objective data maybe used from actigraphy, sleep trackers, sleep EEG devices
Sleep disorders to rule out: RLS, OSA, shift work, delayed sleep phase, nigthmares, narcolepsy

Treatment
1. Preferred short and long term treatment – Cognitive Behavioral Therapy for Insomnia (CBTi)
2. Hypnotics maybe used – discussed in separate chapter