Less time in bed. More sleep.

It does, and it's the most effective part of the approach that clinical guidelines put ahead of sleeping tablets. Spending longer in bed trying to catch up dilutes what sleep you get across more hours of lying awake, and teaches your body that bed is a place for being awake. Compressing time in bed builds sleep pressure and consolidates the sleep that does happen — then you extend it fifteen minutes at a time as efficiency improves. The first fortnight is harder. That's the mechanism, not a sign it's failing.

It's the advice everyone gets and it's the weakest component. Dark room, no late caffeine, no screens — all reasonable background, and as a standalone treatment for chronic insomnia it doesn't do much. That's worth knowing before another month goes by doing only that. The parts that move it are the sleep window and retraining what bed means.

It causes real daytime sleepiness in the first week or two, so anyone who drives professionally or operates machinery needs a clinician's supervision. It isn't appropriate without medical involvement for bipolar disorder, where sleep loss can trigger an episode, for epilepsy, where it lowers the seizure threshold, for untreated sleep apnoea, or in pregnancy. The diary, the bed retraining and the thinking work are all still fine in those cases.

That's screened first, because several things look like it and don't respond to this. Loud snoring with witnessed pauses, waking gasping, morning headaches or feeling unrefreshed despite enough hours suggest sleep apnoea — treatable, with cardiovascular consequences left alone, and reducing time in bed is wrong for it. Legs that won't settle at rest suggest restless legs. Consistent very early waking with low mood is a recognised depression pattern.

Yes, and the programme runs alongside them. What it will never do is tell you to stop or reduce anything — some cause rebound insomnia when stopped and stopping certain ones abruptly is dangerous. Any reduction is the prescriber's decision, and it's frequently done alongside this approach rather than before it. Alcohol gets an honest mention too: it shortens the time to fall asleep and fragments the second half of the night.