The sleep hygiene evidence
Sleep hygiene refers to a set of behavioural and environmental practices associated with better sleep quality. The practices with the strongest evidence: maintaining a consistent sleep-wake schedule (including weekends), keeping the bedroom cool (16-19°C is associated with better sleep), making the bedroom dark and quiet, and avoiding screens before bed (the blue light suppresses melatonin secretion, though the cognitive stimulation may matter more).
CBT-I: the gold standard
Cognitive behavioural therapy for insomnia (CBT-I) is the most evidence-based treatment for chronic insomnia. It consists of several components: sleep restriction (initially limiting time in bed to the actual time asleep, consolidating sleep and building sleep pressure), stimulus control (re-associating the bed with sleep rather than wakefulness), cognitive restructuring (challenging unhelpful beliefs about sleep) and sleep hygiene education. Multiple meta-analyses show CBT-I outperforms sleeping pills for chronic insomnia.
Caffeine and alcohol
Caffeine has a half-life of approximately 5-6 hours — a coffee at 3pm means significant caffeine in your system at 9pm. Alcohol may help people fall asleep initially but disrupts sleep architecture, suppresses REM sleep and causes waking in the second half of the night. Cutting alcohol before bed typically improves sleep quality within days.
When to seek help
Occasional poor sleep is normal. If you are consistently sleeping fewer than six hours, taking more than 30 minutes to fall asleep, or waking frequently, and this has persisted for more than three months, speak to your GP. Conditions including sleep apnoea (causing repeated waking and profound daytime sleepiness) require medical investigation and treatment.