I think that if you ask anyone who knows me in-person they will tell you that I'm an unusually emotionally intensive person. My writing is also usually very emotionally intense but it tend to go through getting feedback from like 20 people who tell me to remove all of the excessive language and to tone it down before publication, so it ends up sounding normal. Comment do not go through this kind of process.
I want to apologize for lack of proper engagement with the post and lack of replies to you as well as a high level of combativeness in the comments I did leave.
This stuff makes me anxious and I feel like I'm just unable to properly explain what makes me disagree so much with you.
My best attempt is that my takes are some combination of:
Coincidentally, I wrote this comment after less than 3 hours of sleep today (had 100 mg of caffeine 5 hours ago and another 100 mg of caffeine 3 hours ago).
Thanks for the taking the time to look into my essay.
Here's what Mendonça writes in her first point that so conclusively demonstrates that the point I make is "misleading":
[Guzey's] evidence from bipolar disorder patients is not representative of what you see in the general population: both long and short sleep duration are associated with depression
The paper Mendonça cites looks at long-term long sleep and long-term short sleep, with their association with depression. My claim and my evidence (from bipolar people) are concerned with short-term long sleep and short-term short sleep. That is, Mendonça's paper is simply not overlapping with with what I write about or what the evidence she calls "misleading" is concerned about. It is further puzzling that in her refutation of my argument she:
I am similarly puzzled by a later accusation:
Guzey claims that “most sleep research is extremely unreliable and we shouldn’t conclude much on the basis of it,” but there are problems with that. Firstly because he doesn’t seem to believe that about sleep research that favors his hypotheses. Guzey, after all, uses sleep research to show that Matthew Walker’s book is terrible and fraudulent. So it seems that he wants to trust sleep research when it says that sleep deprivation is not as bad as Walker shows, but doesn’t want to trust it when it says that sleep deprivation is not harmless.
I wrote that most sleep research is extremely unreliable. And indeed, this is what I believe and this is why I'm so selective with the kind of evidence I use, preferring to show my readers Reddit comments left by bipolar people, instead of meta-analyses, and why, when I do use meta-analyses, I use them very cautiously. For example, in the essay, I used a meta-analysis exactly once when I noted in a point I dedicated to a paper about a study of hunter-gatherers that "There’s no causal evidence that sleeping 7-9 hours is healthier than sleeping 6 hours or less. Correlational evidence [from a meta-analysis] suggests that people who sleep 4 hours have the same if not lower mortality as those who sleep 8 hours and that people who sleep 6-7 hours have the lowest mortality."
What Mendonça seems to miss more generally is that meta-analyses, which she is relying on heavily, do not reflect reality: they reflect the consensus of an academic field. And if the academic field is confused and the majority of the papers published in it are garbage, then meta-analyses are going to be confused garbage as well.
I believe that it is similarly confused. I write about sleep deprivation causing increase in BDNF. What does Mendonça have that contradicts my writing, supposedly by papers I cited myself?
Chronic sleep deprivation and insomnia can act as an external stressors and result in depression, characterized by hippocampal BDNF downregulation along with disrupted frontal cortical BDNF expression, as well as reduced levels and impaired diurnal alterations in serum BDNF expression.
This quote talks about depression (due to chronic sleep deprivation and stress) being characterized by BDNF downregulation. This is not about sleep deprivation per se because sleep deprivation does not necessarily lead to depression.
significantly decreased serum BDNF levels compared with sleep-healthy controls (n=24; F(1)=5.017; P=0.03; Figure 1a). In addition, serum BDNF levels were significantly correlated with severity of insomnia in all paricipants (n=50; rp=−0.409; P=0.004; Figure 1). [...] We found subjective sleep impairment to be associated with lower serum BDNF levels, whereas reported good sleep was related to higher serum BDNF levels, as shown for those suffering from current insomnia compared with sleep-healthy subjects.
This quote talks about people with insomnia having decreased BDNF. People with insomnia have all kinds of health issues and are famous for underestimating how much they sleep (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3277880/) and using them to argue about the relationship between sleep deprivation and BDNF is misleading.
I regret citing this paper in my essay but it's indicative of the overall depth of Mendonça's arguments: instead of noting that using insomniacs as evidence is simply inappropriate for the point I was making and writing that I'm using inappropriate evidence, she doesn't note any issues with it and simply notes that it contradicts my point.
[O]ur findings are in line with the hypothesis of an increased stress vulnerability due to sleep loss which may lead to a decrease in BDNF. [...] While we report a reduction of BDNF levels linked to sleep disturbance reflecting chronic stress on the one side, we and others consistently showed that prolonged wakefulness caused by SD (partial or total), which can be considered as an acute stressor for the brain, leads to a rapid increase of BDNF
This quote again talks about stress due to sleep loss, not sleep loss per se and specifically notes "we and others consistently showed that prolonged wakefulness caused by SD (partial or total), which can be considered as an acute stressor for the brain, leads to a rapid increase of BDNF", so I'm very confused by Mendonça uses it to contradict me.
I don't have the ability to go through every claim in the post and show what exactly is wrong with them, but my read that the rest are similarly confused: they seem to be somewhat related to what I wrote but mostly misinterpreted with their misinterpretations being "refuted" or shown "misleading".
(I'll reply in more substance by the end of the week -- have a big deadline coming up this Thursday)
From skimming the post, three parts stand out to me
1. the fact that acute sleep deprivation relieves depression in ~50% of people with depression seems completely unaddressed and Natália's section about bipolar people seems to imply that this would not be happening. I specifically noted in this the section Natália addresses by writing:
Lack of sleep is such a potent trigger for mania that acute sleep deprivation is literally used to treat depression. Aside from ketamine, not sleeping for a night is the only medicine we have to quickly – literally overnight – and reliably (in ~50% of patients) improve mood in depressed patients
One of Guzey’s theses is that “[o]ccasional acute sleep deprivation is good for health and promotes more efficient sleep.” His argument supporting that thesis is pretty much that, because some types of acute stress (such as exercising and fasting) are good, and acute sleep deprivation causes acute stress, then acute sleep deprivation is also good. (Yes, that does seem to actually be the entirety of his argument in that section. You can read it yourself.)The obvious problem with that argument is that the set of things that cause acute bodily stress is much larger than the set of things that cause long-term benefits. Stubbing your toe, for example, causes acute bodily stress. Guzey’s argument works equally well for showing that occasional toe-stubbing is good for health as for showing that occasional acute sleep deprivation is.
One of Guzey’s theses is that “[o]ccasional acute sleep deprivation is good for health and promotes more efficient sleep.” His argument supporting that thesis is pretty much that, because some types of acute stress (such as exercising and fasting) are good, and acute sleep deprivation causes acute stress, then acute sleep deprivation is also good. (Yes, that does seem to actually be the entirety of his argument in that section. You can read it yourself.)
The obvious problem with that argument is that the set of things that cause acute bodily stress is much larger than the set of things that cause long-term benefits. Stubbing your toe, for example, causes acute bodily stress. Guzey’s argument works equally well for showing that occasional toe-stubbing is good for health as for showing that occasional acute sleep deprivation is.
As far as I know, there's no evidence that stubbing depressed people's toes relieves their depression in 50% of the cases, which combined with the relationship with mania in bipolar people, and the analogical reasoning to exercise and fasting leads me to believe that acute sleep deprivation is good.
3. Natália misquotes me at the end of the piece. I never wrote that 6 hours of sleep is optimal. I have no idea how many hours of sleep is optimal and I believe (please let me know if this is not the case) I never stated that a particular amount of sleep is optimal.
What I wrote in the appendix of the Why We Sleep piece Natália linked to was: "people who have the lowest mortality actually sleep 6 hours a night". Earlier in that article (which, it is clear that Natália read carefully), I specifically wrote "we should almost never use [epidemiological evidence] to claim causality".
The fact that I spotted these three points after spending ~3 minutes skimming the post do not make me optimistic about the rest of the critique, but, as noted above, I will reply in more detail in a few days.
re: persuasive intent -- yes, of course I want to persuade people but I'm believe I'm being very clear about the fact that some sections are just analogies.
My strongest objection to your writing style is the accusation that sleep researchers in general are doing shoddy research and culpable for the equivalent of killing people. This is the point at which I would have stopped reading your article (and lowered my likelihood of reading other things you write in the future), if it weren't for the fact that Elizabeth was the one who curated the piece.
I believe this is a very strong misreading of what I wrote. I did write that sleep researchers in general are doing shoddy research (I'm pretty sure this is true). I never wrote that they are culpable for the equivalent of killing people.
Here's the paragraph this is referring to, I believe:
Why are people not all over this? Why is everyone in love with charlatans who say that sleeping 5 hours a night will double your risk of cancer, make you pre-diabetic, and cause Alzheimer’s, despite studies showing that people who sleep 5 hours have the same, if not lower, mortality than those who sleep 8 hours? Convincing a million 20-year-olds to sleep an unnecessary hour a day is equivalent, in terms of their hours of wakefulness, to killing 62,500 of them.
I thought specifically about how to phrase the last sentence in order for it to be only about facts rather than accusing anyone and the "convincing a million 20-years-olds" appears clearly to be just a thought experiment to me.
This I agree with. As I noted in another comment, Guzey's a lot of things right here, except that the tone and format of his post makes his argument feel hard to respect. It comes across as ranty, manic, highly motivated ("passionate"), the sort of style we now associate with Qanon. But this is LessWrong, and I think that here, at least, we should try to focus on substance over style.
Tbh I'm very confused about the issues you have with my tone. I very deliberately called the post "Theses" on sleep! And I believe I very explicitly wrote that these are my conclusions from my reading of the literature and in no way am trying to make people think that the analogies that I thought of that I find convincing should be convincing to other people. I simply put forward some theses with extremely variable level of evidence between them but for each of these it is the case that I personally am convinced that they are actually true.
Yep, if someone was majorly undersleeping for a few days, they are probably going to be more sleepy and make more mistakes of attention/find it more difficult to concentrate and absorb the kind of information that they would need a tutor to absorb!As an experiment -- you can ask a couple of your students to take a coffee heading to you when they are underslept and see if they continue to make mistakes and learn poorly (in which case it's the lack of sleep per se likely causing problems) or not (in which case it's sleepiness)
Have you done an explicit calculation of your perceived increased risk in Alzheimer's and compared it to QALY (potentially) gained by decreasing amount of sleep?
Yep, I sometimes manage to ask my body to wake up at a certain time and it does it when there's something I care a ton about waking me up a few minutes before the alarm.