Sleep study finds latest time you should go to bed before it starts harming your mental health

A team of medical researchers from Stanford University have revealed the recommended time to switch your lights out to sleep by before your mental health could end up being negatively impacted.

Nearly 75,000 adults in the UK of middle and older age were included in a survey looking into how going to bed earlier and rising earlier versus staying up late and rising later can impact mental wellbeing.

The study

The survey - published in Psychiatry Research last year - saw the participants get asked about their morning or evening preference - i.e. whether they prefer to go to bed late and wake up later or go to bed early and get up early.

"Among the 73,880 participants, 19,065 self-identified as morning types, 6,844 as evening types and 47,979 as somewhere in the middle," Stanford Medicine reports.

This was considered alongside participants' chronotypes too - 'chronotypes [the] natural preferences of the body for wakefulness and sleep,' Sleep Foundation explains.

The adults were sent wearable monitors to track their sleep and activities over a seven day period and their 'sleep behavior' was divided into three categories - the earliest 25 percent considered 'early sleepers,' the middle 50 percent intermediate and the latest 25 percent late sleepers.

This was done rather than using specific times given early or late can mean different things for different groups - for example, college students not seeing a 1am bedtime as late.

The sleep patterns were then looked at alongside the participants' mental health records.

You may think you work better late at night, but is it worth the risk to your mental health? (Getty Stock Images)

The results

Despite some arguing they're simply a 'night owl' and work better into the night, going to bed later and waking later and their body seemingly preferring this too, the study found no matter what people believed their 'best' routine to be for them and their body, it didn't quite work like that.

Stanford Medicine notes: "When the researchers analyzed the data, they were surprised to find that aligning with one's chronotype was not the best choice for everyone's mental health. It was better, in fact, for night owls to lead a misaligned life.

"[...] The results were clear - both morning types and evening types who went to sleep late had higher rates of mental health disorders, including depression and anxiety."

The recommendation of when to go by then, whether an early or late person? Lights out by 1am latest.

But what happens if you don't?

Lights out by 1am, okay guys? (Getty Stock Images)

Well, the 'worst-case scenario' was 'definitely the late-night people staying up late,' professor (Research) of Psychiatry and Behavioral Sciences and senior author of the study, Jamie Zeitzer, said.

And compared to those following an intermediate or early sleep schedule, those who stay up late were found to be 20 to 40 percent more likely to have been diagnosed with a mental health condition.

"Evening types who followed an earlier schedule fared better," the study added. "Morning types who followed a later schedule suffered, but not too much."

Zeitzer resolved: "We found that alignment with your chronotype is not crucial here, and that really it's being up late that is not good for your mental health."

It's no surprise those who got up earlier in the morning tended to have the best mental health either.

However, Zeitzer notes it's still not clear 'why' being up late is 'not good for your mental health'.

Spring is coming, which means longer days (Getty Stock Images)

He theorizes 'a guess' is that 'morning people who are up late are quite cognizant of the fact that their brain isn't working quite right, so they may put off making bad decisions' whereas evening people who are up late may think they're making a 'great decision at three o'clock in the morning' - with alcohol and drugs more likely to then have contributing factors at that time too.

But what happens if your chronotype is going to bed late?

Well, you have to work at it. Try getting into a routine getting into bed a bit earlier and earlier each night and waking up in time to catch some sunlight.