Selected Research From SLEEP 2023

By LUDWIG VON KOOPA - We hope you have a good night after reading about these seven studies.

In honour (or dishonour) of my total lack of sleep due to the recent reaction log deep into the night with the disappointing Grasshopper Manufacture Direct, let's turn our attention to SLEEP 2023, which was a conference that took place this year during June 3–June 7 in Indianapolis, Indiana. SLEEP is brought to sleep professionals every year by the Associated Professional Sleep Societies (APSS), a collaboration of the American Academy of Sleep Medicine (AASM) and the Sleep Research Society. The names of those should tell you that SLEEP is where professionals in sleep medicine—both researchers and practitioners (and students of those)—come together to share learnings and best practices. Oh, and to network!

There are hundreds of abstracts involved in the meeting and there were many sessions, including an advocacy session ran by our friends in common cause, Save Standard Time and Dr. Karin Johnson. Here is a sampling of seven studies that SLEEP's news section highlighted and my thoughts on them. ...Note that I didn't actually attend the conference.

Teens with irregular sleep patterns have higher risk of school problems

The first study suggests that the keys to a good sleep for teenagers are sleeping for long enough (8–10 hours), at the right time every time, and not being interrupted. When teenagers have a greatly varying sleep schedule or habits, they are much more likely to perform poorly in school, such as being 42% more likely to be suspended or expelled or 29% more likely to receive a D or F as their course grade. Researchers therefore believe that teenagers ought to get a stable sleep schedule in order to perform better in school and be better behaved.

Newborns with higher hair cortisol levels take longer to fall asleep

A new study claims that cortisol levels in late pregnancy can predict infants’ sleep. That link doesn't explain what cortisol actually is, though I've tried to explain it before back in 2022. Cortisol is a hormone that gets released every day, and if you're stressed out, more gets released. It's supposed to control your blood pressure, metabolize glucose, suppress immunity, and prevent inflammation.

The study's results—taken from measuring cortisol in baby hair—show that higher cortisol means the babies took longer to fall asleep. The cortisol from the infants apparently come from their mothers, so greater stress in late pregnancy might mean babies have a worse time trying to fall asleep post-birth. That's important not just for the parents, but also because sleep researchers have previously linked poor sleep health as a baby to worse physical and mental health after that baby has grown up. SLEEP only cares about the affects on sleep, but other research on prenatal stress and cortisol levels indicates all sorts of other issues as well, such as depressive disorders and anxiety passed on to the baby. You can still be a stressed pregnant mother (it seems hard to NOT be stressed while pregnant!), but there seems to be an unspecified point where it becomes particularly problematic.

Phototherapy device has potential to be a novel treatment for sleep complaints

This study stuck collars that emit near-infrared light onto people, had them sleep, and recorded the results. (Well, the results were self-reported.) Those results show that people—the sample of people all started with sleep issues—got better sleep quality and felt better when they woke up compared to “inert sham devices.” The researchers stressed that more research needs to be done before people should take conclusions from that. I've wanted to find a photo of this collar, but haven't been able to. The device is apparently created by a Ceraz LLC, but no findable information about this company exists. I suppose the APSS didn't highlight this study for its conclusions but rather as a new research direction they want to see more studies on in the future.

Sleep loss moderates link between youth impulsivity and mature-rated media usage

When this study discusses mature-rated media usage, they are looking at both R-rated movie watching and Mature-rated videogame playing.

This is a complicated and awkwardly created cause→effect. You need to read the word “moderates” as being “a factor that affects the relationship between youth impulsivity and mature-rated media usage.” (It can make it stronger or weaker.) The study found that for adolescents (think 13-year olds), they found that kids who have impulsive personalities are more likely to watch R-rated movies. If they don't sleep enough, all kids are more likely to play mature videogames and watch R-rated movies. But kids who have high impulsivity who don't sleep enough are more likely to watch R-rated movies. (Apparently this doesn't affect videogames, or the study authors just didn't mention it.)

The study also claims that “exposure to mature-rated media in youth is associated with decreased empathy and aggressive behaviors later in life.” However, that statement was just thrown in there in the introduction, and wasn't supported or measured by the experiment. I'm not a fan of this study. I thought of a viable and alternate explanation of the study's main effect. If kids are too busy sleeping and are sleeping more, they aren't using that time for watching movies or playing games, so of course they'll be doing those things less. There are only so many hours in a day. Let's move on to a less controversial and less stupid claim.

I sleep with my eyes open because of my trauma.
When they talk about sleep quality, mine probably sucks.

Adults with a regular, healthy sleep schedule have a lower risk of death

Well, this study headline makes sense. Much more sense than the previous one. Very straight-forward. Anyway, a regular sleep schedule isn't just about how much sleep you get, but going to bed and waking up at similar times every night and day. Which means staying up extra late for Grasshopper Manufacture's Direct? Not great for my health (or ability to remain alive), even if I slept in for 8 hours afterward, because it's way later than when I'd normally go to bed (or wake up). The magic percentage the researchers came to was a 39% lower mortality risk for healthy, regular sleepers versus irregular sleepers.

Survey finds that sex is as good as — or better than — a sleeping pill

This is not a study I can take part in. According to self-reporting that only involvied 53 adults (89% of which were between 25 and 49 years old), 75% of survey respondents “felt” that they slept better after having sex close to bedtime, and that sleeping pills had a less than or equal to positive effect as sex did. This is definitely not a rigorous study, and it seems like the study authors want far more research done on the intersection of sexual activity, orgasms, and sleep health. Perhaps they'll observe this in a lab next.

Study identifies two aspects of sleep related to depression in college student athletes

The final study claims that “perceived sleep quality and difficulty maintaining sleep” are tied to the relationship between general sleep disturbances and the severity of depression among college student athletes. (The study says those are mediators, which means that sleep disturbances cause poor sleep quality and difficulty maintaining sleep, and poor sleep quality and difficulty maintaining sleep cause deeper depression.) The study did not find that the duration of sleep, nor the time it takes to fall asleep, were significantly affecting this relationship. Their conclusion is that, with regards to depression (in college student athletes), medical professionals ought to look into improving sleep quality and keeping patients asleep throughout the night as more primary tools over other facets of sleep.


A fair number of these studies are likely bogus or useless, especially with the self-reported surveys or small sample sizes. Hopefully you found something noteworthy or useful in this write-up, though. Now go get some sleep after writing a comment in the comments section. Ludwig isn't a medical professional of any kind and science is his knowledge blindspot, so if he explained anything incorrectly or fundamentally misunderstood some concepts, please correct him in the comments section.


KoopaTV wrote a similar article for SLEEP 2022, except there were ten studies then.