Anyone can have trouble falling asleep from time to time. It's estimated that up to half of UK adults suffer from short-term episodes of insomnia. And for a smaller subset of people, this can turn into chronic insomnia, which is defined by trouble falling or staying asleep at least three nights a week for longer than three months. The question is: Why do some people get back on track while others continue to struggle?New research suggests it may have something to do with how much time one spends in bed trying to catch up on sleep.The study, to be presented this week at this year's meeting of the American Academy of Sleep Medicine and the Sleep Research Society, looked at a group of 539 people who had kept detailed sleep diaries for six months. Of those, 394 were considered "good sleepers"; 36 were good sleepers who developed short-term insomnia but recovered, and 31 were those who developed long-term chronic insomnia.The researchers noticed that the good sleepers didn't change the amount of time they spent in bed over those six months. Those who developed short-term insomnia understandably spent less time in bed as it became harder for them to sleep. But those who went on to develop chronic insomnia spent more and more time in bed as their sleep woes got worse.Although it's tempting to take any opportunity to make up for those lost Zs, the research here suggests that might not be the best strategy in the long term. "[People with insomnia] go to bed early, get out of bed late, and they nap," said lead author Michael Perlis, PhD, in a press release . "While this seems a reasonable thing to do, and may well be in the short term, the problem in the longer term is it creates a mismatch between the individual's current sleep ability and their current sleep opportunity; this fuels insomnia."Instead, you should try to stick as closely as possible to a sleep schedule, even when you're feeling like you didn't get enough restful sleep the night before. Going to bed and getting up at about the same time every day helps train our bodies to fall asleep when we need to.