Insomnia

Insomnia disorder is defined by dissatisfaction with sleep quantity or quality — trouble initiating sleep, maintaining it, or waking too early — occurring at least three nights a week for three months or more, despite adequate opportunity to sleep, and accompanied by daytime impairment. That last clause matters: someone who sleeps six hours and functions well does not have insomnia. The condition is usually maintained by different factors than those that started it. An acute stressor triggers a few bad nights; the response to those nights — going to bed earlier, staying in bed awake, catastrophising about tomorrow — creates conditioned arousal that outlives the original trigger. This is why cognitive behavioural therapy for insomnia, which targets those maintaining behaviours directly, outperforms sedatives over the long run and is recommended as first-line treatment by the American College of Physicians and the American Academy of Sleep Medicine. Roughly 30% of adults report insomnia symptoms in a given year and about 10% meet criteria for chronic insomnia disorder. Prevalence rises with age and is roughly 1.5 times higher in women than men. Supplements sit at the margins of this picture. Magnesium and ashwagandha have small trial effects on sleep onset; melatonin is a circadian agent rather than a hypnotic and works best for phase problems and jet lag. None of them approaches the effect size of CBT-I, and using them to avoid addressing the behavioural pattern usually prolongs the problem.

• •Difficulty falling asleep
• •Waking repeatedly during the night
• •Waking too early and unable to return to sleep
• •Non-restorative sleep
• •Daytime fatigue and low energy
• •Irritability and low mood
• •Difficulty concentrating
• •Anxiety about sleep itself

• •Acute stress or life change
• •Conditioned arousal from time spent awake in bed
• •Irregular sleep-wake schedule or shift work
• •Caffeine, alcohol or nicotine
• •Anxiety and depression
• •Chronic pain
• •Obstructive sleep apnoea
• •Restless legs syndrome
• •Medications including stimulants, steroids and some antidepressants
• •Perimenopause and menopause

Chronic insomnia is usually best understood through the 3P model: predisposing traits such as a tendency toward hyperarousal, a precipitating event such as illness or stress, and perpetuating factors — the compensatory behaviours and beliefs that keep the problem going after the trigger has passed. Treatment works by removing the perpetuating factors, which is why extending time in bed to catch up almost always backfires.