The effects on cognition of sleeping 4 hours per night for 12-14 days

I can summarize what both the original author, and what the person wrote criticizing agree on. Yes, sleep is required. Get enough sleep that you feel rested.

A lot of the critique was around the 8 hours, and the conclusions about what happens if you get less.

Anecdotally, I never sleep 8+ hours. I also get up without an alarm clock every single day. I'm not going to stress that I normally sleep ~7 hours and feel rested when I wake up. I know on the rare occasions if I get less than 6 hours, I'm going to be really tired that night.

> Ergo, ADHD might have a large sleep component.

Yeah, I can count on one hand the number of times in my life when I woke up in the morning, even after a good night of sleep, and felt "refreshed". I didn't even know what that meant until I had a conversation with a coworker who just hops out of bed and is "on" immediately. Feels like there is a connection with my ADHD diagnosis.

> The weird thing is that it doesn't feel like I can't keep going... it's just that I sort of somehow don't keep going. I find my mind wandering more easily

That's exactly what I experience if I have a few too many days where my sleep is interrupted or I sleep badly. I already give myself very little leeway there, where I usually have about 5.5 to 6.5 hours before I need to wake up (I fall asleep very quickly), so it's a fairly good gauge of time). If something wakes me earlier than expected, it affects me the next day.

I find that coffee makes this harder to determine, as I'll still feel alert that next day, just as if I had better sleep, but I'll be less productive overall in all the ways you mentioned. I can still think coherently, but I appear to be able to do so about the same thing for a much shorter period before being distracted with something else.

> As I have come to understand this impact, it has given me greater empathy for addicts. My brain doesn't feel like a tired muscle, or like I'm doing anything wrong in the moment.

That's a very astute observation. I've noticed before that more sleep makes me more productive, yet there's always that allure to staying up a bit later and reading a little bit more in the book I'm reading (which is almost always the problem), or watching a little bit more, etc.

Like an addiction (I assume), the path from non-problematic behavior to problematic behavior is somewhat gradual, and noticing the problem is somewhat impaired by the negative effects of the problem itself. I don't set out to sleep very little, it just gradually gets worse where I'm skimping on sleep more and more often, until it's fairly consistent, and then I eventually notice and break out of it. Then the cycle repeats, but I generally spend far more time with little sleep than adequate sleep overall.

I did it too for a few months. Felt great just doesn't work with society at all. 3h+ blocks are useful, especially when you need to get somewhere in a bigger city. And missing a nap is like missing a night of sleep, except it's not that easy to catch up without screwing your schedule. I did not have problem not being able to focus on something for 3h (btw AFAIR it was 2.5h for me? with 24 mins sleep). Nap felt like a pause, I could continue coding as if I went to the bathroom. Very much unlike me needing 1h in the morning to establish where exactly up and down are.

For startups - forget it unless you are going alone with no funding. Meetings just don't work. Nap have to be at exact times. It just doesn't work with social norms we have.

Also, switching is hell. It's a torture.

I discovered that about 1/3 of people can be sleep deprived without any ill effects, which is the bucket I fall in. Another 1/3 will be disgruntled but can function at a lower level, but for the last 1/3, it's catastrophic and can't function at all. That's my wife, and what exemplified this the most was after having kids. She was almost immediately a wreck but I was able to hold together with the lack of sleep and spent most of the time being the caregiver for our kids during the toughest parts of the night.

Previous, I had another incident of sleep where I got 4-5 hours of sleep a day for about a year, and then it all came crashing down on me eventually.

About 10 years ago, I was doing algorithmic trading globally and would sometimes watch my trades until 1-2am, and then wake up at 6am to be ready for US trading. I was doing fine with no problems from lack of sleep, and then one day after about a year I stopped being able to think clearly. I was having real trouble thinking or learning new things and had a bad headache. I went to my doctor and she immediately scheduled an MRI because she thought I might have a brain tumor. I was scared shitless, but I was able to get the MRI the next day. After the results came back negative for brain tumor, I thought maybe it's sleep, so I left work in the middle of the day and fell asleep and slept for about 16 hours. I realized right there and then I was sleep deprived, so I stopped trading immediately and focused on trying to sleep properly.

These days I need close to 7.5 hrs of sleep a day and if I get less, I'll feel it pretty quickly as opposed to 10 years ago when I felt nothing.