Researchers Don’t Think We’re Meant To Be Awake Past Midnight

You probably already know that people have different “chronotypes”, or natural sleep-wake patterns.

Some of us really are born early birds or night owls. And trying to “beat” your body’s built-in preference might have negative effects, like potentially making your workouts less effective.

But there are limits here, too. For instance, a 2024 paper found that even for those with late chronotypes, it’s best for their health to go to bed before 1am. This result surprised researchers so much that they spent six months trying to disprove it – but couldn’t.

A separate 2022 study titled “The Mind After Midnight” carried an even more extreme warning.

“During the biological night, cognitive capacity and mood regulation are diminished and ‘reason sleeps’”, it reads.

The ‘mind after midnight’ hypothesis suggests being awake very late may impact “attentional biases, affective regulation, reward processing, and executive functioning” which can “set the stage for dysregulated behaviors and psychiatric disorders”.

That all sounds pretty intense, doesn’t it? But we do know that crime rates, substance abuse and overdoses, impulsive eating, and suicides seem to happen disproportionately often at night, when our “biological circadian night” (after midnight for most of us) is in full swing.

The study’s senior author, Dr Elizabeth Klerman, said that “from a high-level, global, evolutionary standpoint, your internal biological circadian clock is tuned towards processes that promote sleep, not wakefulness, after midnight”.

So, she argues, neurophysiological changes take place in our minds during the wee hours, because we’re primed to be alert in situations like these.

Her study suggests that positive affect, or our tendency to see things in a better light, peaks in the daytime. But at night, negative affect – a negative view on life – becomes far more common.

Meanwhile, the body produces more dopamine when you’re awake too late, which could drive impulsive behaviour. This, combined with a worse outlook on life, might help to explain some of those troubling nighttime stats.

Dr Klerman said “there are millions of people who are awake in the middle of the night, and there’s fairly good evidence that their brain is not functioning as well as it does during the day”.

She added: “My plea is for more research to look at that, because their health and safety, as well as that of others, is affected.”

So far, mind after midnight theory hasn’t been the topic of a formal trial – but these are in the works.

However, this is far from the only paper to suggest that our brains might not run at their best when we should be sleeping.

Dr Jamie Zeiter, the author of the sleep and chronotype study we mentioned earlier, said: “If I had to hazard a guess, morning people who are up late are quite cognisant of the fact that their brain isn’t working quite right, so they may put off making bad decisions… Meanwhile, the evening person who is up late thinks, ‘I’m feeling great. This is a great decision I’m making at 3 o’clock in the morning’”.

This could put night owls who stay up too late in harm’s way, he suggested.

Another paper found that those who said they like to sleep late tended to have more repetitive negative thinking.

Speaking to HuffPost UK previously, registered dietitian and longevity specialist Melanie Murphy Richter said: “Going to bed between 10pm and midnight and waking with the sun supports circadian rhythms, hormone balance, and cellular repair – all critical for healthy ageing”.