How do they know the causal link? Can it be that people who stay up late sleep less and this causes issues, and there being light is only a consequence of staying up late?
There's more details further in the article[1].
[1] https://www.medrxiv.org/content/10.1101/2025.06.20.25329961v...
In any case, light sensitivity and sleep patterns are well linked. If you live far away from the equator, you are dealing with pretty short nights half of the year. I lived in Helsinki for a while. That can really mess up your sleep though some people manage to adapt. There's a reason coffee is popular in places like
I currently live in Berlin. I sleep about 2-3 hours less in the summer than in the winter. Somehow that works for me. But it's really annoying to be wide awake at 6 when you've set your alarm for 8. I'm literally typing this on my laptop early morning on a Sunday. But it's light very early this time of year.
I've experimented with wearing sleep masks. They really work. But I find them slightly uncomfortable. What works better is just doing sane things like trying to live healthy. Less alcohol, more sport. Etc. Work stress can cause all sorts of issues with that.
That's not OK, I don't know a single person affected so (live in cca same latitude as Berlin). Have you tried some radical solutions like good window blinds or similar sun blocking mechanisms? I don't mean some cheap crap that still lets strips of light through, I mean full block. Of course if then some chopper or ambulance wakes you up regardless it doesn't matter.
These days I don't drink alcohol any more, which has done wonders for my sleep quality. Quitting alcohol works better than almost anything else you can do. Long summer nights of drinking beer in the park (which is one of the perks that Berlin has) are not that great for this. But still, I easily sleep to 9am in the winter and in the summer I usually am awake a lot earlier. I typically stay in bet for a bit.
Btw, did you take a D vitamin supplement and use a light therapy lamp in the mornings?
The dark/light situation never affected me that much. But I could definitely see it in people around me. People from further south have a hard time dealing with darkness. Insomnia is something to guard for.
The Finnish are famously one of the most happy people around. But they also have relatively high suicide rates that spike in spring when after a miserably long winter, the availability of light pushes some people over the edge. As I used to morbidly joke, "Finland is so happy because all the unhappy people keep killing themselves thus removing themselves from these surveils". The Finnish love dark humor like that. This got a chuckle out some of them.
Meanwhile, the fortunate outliers are more in the south: Cyprus, Greece, Liechtenstein, Türkiye, Italy and Luxembourg.
I see it constantly when a study comes out all of these statistics students come out of the wood work and say "Correlation doesn't mean causation" without any other thought.
The study clearly claims only a correlation and absolutely, correlations help focus attention to try and find causal links in the future.
However, I think you are just being triggered by past traumas, because nobody said that here.