Having just become aware of the existence of the term Delayed Sleep Phase Syndrome (Wikipedia), despite having had "symptoms" nearly all of my life that fit the "diagnosis" (I think you can tell from my scare quotes where I'm going with this) I'm wondering if it is, to put it bluntly, real.
That was my provocative introduction. Here are the facts. I have always felt most comfortable going to sleep late and waking up late. In the times in my life (college, etc.) when I didn't have to wake up early every day, I would generally gravitate toward a late schedule: say, 3:00 am til 11:00 am. This meant unfortunately that the occasional 9:00 obligation was a total nightmare. I tried again and again to wake up earlier, but even if I did I would inevitably drift forward. I just did not get tired at the earlier time like most people do. But once I set into the 3:00 am bedtime, I would get reliably tired at that time, fall asleep, and stay asleep. That's why this is different from insomnia. I could go on and on about my experiences, but I'll spare you. Let's just say I have been annoyed to death over the years by people giving me advice when they clearly just have bodies that are different from mine. The worst is when people imply I am lazy. It's an incredibly frustrating situation because you want to shake them and say "just open your d*mn mind for fifteen minutes and try to understand where I'm coming from." Oh wait, that's also what it's like to be paleo ... I digress.
Now I've read a couple of books on sleep and sleep research, and one thing I learned (in addition to learning that people tend to drift forward in their sleep schedules if they are in sealed apartments without windows or any time cues (Zeitgeber)) was that sleep researchers generally classify people as "owls" and "larks." Some people just have an easier time falling asleep at night or reverting back to an early schedule, and some people are the opposite. So DSPS would just be an extreme version of an "owl" pattern.
After reading that Wikipedia article I was ready to begrudgingly admit that there was something wrong with me, but a passage toward the end caught my eye.
DSPS is a disorder of the body's timing system—the biological clock. Individuals with DSPS might have an unusually long circadian cycle, might have a reduced response to the re-setting effect of daylight on the body clock and/or may respond overly to the delaying effects of evening light and too little to the advancing effect of light earlier in the day. In support of the increased sensitivity to evening light hypothesis, "the percentage of melatonin suppression by a bright light stimulus of 1,000 lux administered 2 hours prior to the melatonin peak has been reported to be greater in 15 DSPS patients than in 15 controls."
Here's my thought. I have a hard time accepting that those of us who are "owls" or even extreme "owls" would be sleeping into the day in a pre-agricultural, pre-industrial setting. So it must be the case that, were the night-time light stimuli not present at all, there would be no DSPS sufferers. But those of us who do fit the pattern are just more sensitive to the stimuli that are nearly inevitably there -- as my block quote suggests. I think a powerful analogy can be drawn to obesity. There were probably no obese paleos. And yet it is not the case that nowadays everyone is obese. The best explanation is that conditions exist which some people are more sensitive to than others. These are the obese.
What do you think? I hesitate to settle on this as a complete explanation -- in part because that is a good policy to follow in general, but also because there are a few peculiarities: one is that the late-sleeping tendency is much more prevalent in adolescents and especially in male adolescents, which could accommodate biological explanation. (I recall recently seeing some publicity on studies showing that we are basically waking up our teenagers way too early for school and making their lives miserable.) Any other theories? Anyone want to share experiences? There is an older paleohacks thread that addresses this, but I wanted to ask about my pet hypothesis, and also this is a important topic to me and I'd be delighted to hear what people have to say. Apologies for the long question. Paul.
I entirely take the point about the idea that DSPS-symptoms might somewhat result from individuals merely having differential responses to factors that are (largely) unavoidably in the modern environment, but (largely) absent in the paleo context. I wouldn't say that accepting this means that DSPS is not "real" however.
My own experiences rule out the possibility that DSPS is merely natural entrainment from more or less normal sleep times to increasingly later sleep times as people choose to stay up later than their natural sleep time, progressively. In mid-late adolescence (the time symptoms typically present themselves), I quite quickly moved from a standard sleep cycle to a later one (sleeping from 1-4am), which I of course first identified as insomnia and was diagnosed by my GPs as such (and endlessly given irritating, useless advice- to drink less caffeine near bed and not stay up playing computer games, when I was doing neither). With hindsight though, it was clear that it wasn't really insomnia, since I was able to sleep quite comfortably once a certain hour hit, rather than just being unable to sleep generally. Indeed, latterly my sleep cycles were such that I could sleep more or less instantaneously once it hit around 6am, despite having been awake and alert all night previously. It goes without saying that over the years of torture through these means, I removed pretty much everything that could conceivably be said to limit sleep (no caffeine, proper exercise, no bright lights before bed). I would endlessly just lie in bed, in complete darkness, not doing anything for whole nights (before learning that "sleep hygiene" dictated that I shouldn't do this, but get up and do something monotonous out of bed). It's also worth nothing that I couldn't simply compensate by sleeping later during this period, since I was woken for school before 7am every morning and had church on a Sunday, so only had 1 day of sleeping in. I just got by on my 4 hours or so sleep per night by taking ever larger amounts of caffeine, sleeping about 16 hours on a Saturday and even longer during the holidays, as well as napping as soon as I got home from school. It also seems dubious to me that modern light could have such a drastic effect on sleep cycles, given that I could go to sleep quite easily just after dawn and would sleep through easily until past noon.
Anyway, the conclusion I draw from these experiences, is that no environmental changes (including being transported to the paleo era) would have had a dramatic effect on my sleep cycles. No amount of exercise, bright light and absence of screens, would I think, have removed the problem, given that these factors were fairly closely approximated during my experience without any effect whatsover. Indeed, at one point my GPs decided to prescribe me the strongest sleeping pill they had, just for one week (having declined to prescribe any previously), which just had the result of making me very drowsy for about an hour, but then I just woke up (as though to greet the dawn) and got on with critiquing a friend's philosophy essay quite merrily. Conversely, as soon as I was provided with a small dose of melatonin, I slept quite easily immediately.
As to the idea that we can't imagine any paleo HGs with DSPS: I agree that it would seem odd to have large numbers of these integrated into paleo society. However, we should recognise that DSPS afflicts only about 3 in 2000 people (0.15%) and that's in the current environmental context which is inimical to sleep and health anyway. The fact that such extreme variations in sleep cycle seem evolutionary problems, should not, I think, lead us to rule out the idea that they could just be inherent traits. There are plenty of plainly genetic disorders which are evolutionarily detrimental (Downs affects 1 in 800 people, not wildly different from DSPS). I suppose it's also not impossible that incidence of DSPS has increased during our evolution since paleo-times, since there's no longer a selection pressure killing off those people with distorted sleeping. In any case, I don't think we should imagine that people with sleep patterns from 6am-2pm would live just like that in a paleo context. They would probably do more or less what I did: get kicked awake without enough sleep on a fairly frequent basis, collapse into naps whenever they could, function highly suboptimally most of the time while being mildly sleep-deprived constantly. I managed to stumble through school and my first year of university living like this and achieve well, so evolutionary downsides aside it would probably be possible to survive as a paleo-DSPSer. I think that recognising that there are distinct circadian rhythm disorders (advanced sleep phases, non-24 sleep phases, split sleep phases, irregular sleep phases etc) is the best way to understand the phenomenon (aside from those people who are semi-consciously sleeping late as a lifestyle choice).
I'm an owl too. I have this romantic notion that we were the first astronomers. Everyone else got bored and went to sleep, while we sat up, tended to the fire, and charted the skies.
I've dealt with DSPS for all of my adult life. It started when I was in high school. I took Ambien for eleven years, and five years of that time, Ambien was taken everyday. Ambien withdrawal sucks big time. That was one of the hardest things I have ever done and is not recommended to get on this crap everyday for any period of time over two weeks. I tried other things like melatonin. This did not work at all for me. It gave me migraines. Plus your endogenous melatonin downregulates when taking exogenous melatonin, so when you go off the stuff you go through fun times while your endocrine system adjusts. Hormones are interesting things.
I have been in sleep research studies. More on this in a moment.
Advanced sleep phase syndrome is similar to DSPS, just at the other end of the sleep spectrum. Researchers found that there are specific genes related to both ASPS and DSPS. Go the Wikipedia pages for both, and Google DSPS and genes. So while behavioral and other sleep hygiene patterns can be contributing factors, there are people who have a genetic reason for this.
After getting real worked up about this one time when I was in to see my doctor, he said that it was possible I was like this and to accept it and make things work in the context of my life. He said that in Paleolithic times that some of the tribe needed to be up at night to guard the camp or cave from predators.
I took some solace in this and remade my life. I have been self-employed to work around my schedule. I would not have been as successful as I am without being in business for myself. This has resulted in a lot of wealth, which I doubt I could have achieved working 9-5 for someone else.
Back to the sleep research studies I participated in. The study at the University of Utah found that my blood levels of melatonin spike approximately four hours later than day schedule people. My basal metabolic temperature is highest at night.
All of this feeds into my body not being able to go sleep at what most people consider to be a normal time. Right now my to sleep time ranges from 2:00-3:00 a.m., although four years ago, it was not uncommon for me to go to sleep from 6:00 to 8:00 a.m., which is not optimal for interacting with the world.
I am not shy of sunlight and light. In the late spring, summer, and fall months where I live, I get out in the sun for an hour a day.
My thoughts is it is probably like many things in science where the explanation is quite complicated and interrelated with numerous things at play here (thus the reason we don't have a good "solid" explanation yet).
I also have the same night-owl tendencies you do, my optimal sleeping time being 4am - midday
It's hard to disentangle cause and effect in my lifestyle as I am always trying new lifestyle tweaks from diet & supplements to exercise and activities. However I do beleive I have had some success in 'correcting' my primary onset insomnia with Melatonin as has already been mentioned. Looks to be very safe, so I would certainly at least try it out! Then be sure to get GOOD morning exposure to light to help reset your clock.
There is also one real easy way to test your hypothesis; get some special glasses that filter out the blue light which disrupts Melatonin production, and give them a test run for a while. This should help separate the light being the culprit in this problem, with other factors like simply reading really interesting Paleo articles or having online discussions keeping you alerted and not in the 'winding down' phase potentially optimal before sleep.
I also had a commentator once say something really interesting which ringed very true to me; when people such as yourself and I were growing up, we probably spent most of this late night time on computers (or with digital media) playing games or reading or chatting, etc. Staying up late is fun, every kid wants to do it, so when we had nothing to be up for the next morning we would stay up late because it was fun and we were doing fun stuff. But I know myself certainly have spent more nights than I could count quite dreary eyes and tired in front of the computer, or played games till 4am then flopped into bed and be sleeping within almost second. What this person said is perhaps we have "trained" ourselves out of being tired, or with staying awake despite feeling the feelings of tiredness. Over many years and thousands of nights we have essentially stuffed up our whole bodies normal mechanisms for sunset, melatonin production, sleep sometime shortly afterwards.
So now when our body/mind starts becoming "tired" in the normal sense, we have created an adaptation to remain wakeful. I like the word adaptation here, because it has great Paleo reasoning. Our brain has no idea that the interest and attention we are spending on computers late at night is quite trivial (although all of those hours probably led me to Paleo!), go back ~20K+ years and any intense level of attention and interest like that would be in deciphering the complexity of nature, or securing mates, or something very dependant or advantageous to our survival. I don't know how this fits in with the fact not everyone suffers from it, perhaps you and I get more emotional reward from late night activities, or maybe your hypothesis is correct in it being biology but not for light-sensitivity but rewiring our brain or neurochemistry for wakefulness.
At the end of the day; I haven't found a fully satisfying answer yet but I am confident that this very powerful evolutionary lens will provide a clearer view.
Interesting theory. I wonder what would happen to the definition of an owl if you controlled for procrastination tendency and attachment to media. I am an owl of that variety, and can imagine being a normal sleeper if circumstances didn't allow me to do those things.
Try melatonin. I've been taking it for about 8 years now.. For both sleep regulation and for it's longevity promoting abilities. It's a great supplement. I swear it's keeping me from aging.
Interesting... I considered myself to have DSPS for most of my life; a typical night own who found it impossible to go to bed much before midnight and equally impossible to get up on time for nearly everything. I was once fired from a job for excess tardiness.
Now I'm pretty much in bed between 10-11pm. This has been true since last summer when I changed jobs and had to be up early. I don't think evening light exposure had anything to do with it more of a fear of losing the job given this economy. Since going paleo/primal this winter it's gotten easier to get up and often I'm already awake when the alarm goes off.
Not saying it was diet that finally fixed it, but people who have known me for a long time still don't believe I get up at 6:30 or so every day now, maybe a bit later on weekends.
Oh by the way, using the "Flux" tool to slowly change your computer screen from daylight (6500°K) to something less blue/bright (4100°K) helps a lot. It looks really odd when it kicks in but you very quickly don't notice it.
I posted the earlier thread you mentioned, and I have wondered about this exact same thing myself. Like you I maintain a regular sleeping period when allowed to sleep freely (even later, in fact: 4 AM to noon for me).
My anecdotal experience is that when I am hiking in the woods, and then camping at night, I am able to fall asleep at a "normal" bedtime. This suggests to me that DSPS is really something like an extreme sensitivity to environmental light cues. (I can't rule out a contributing role of exercise here, but my usual strength/HIIT routines alone can't put me to bed earlier.)
If this is true, it is unclear to me why we would have such regular sleeping periods - why not just keep staying up until fatigue hit? Also, what about other circadian rhythm disorders?
I also have always been a night owl, and have a horrible time waking up in the morning, as my work can attest. I usually roll into work between 10 and 11 in the morning, even though I always have the intention to wake up earlier. I will say I don't have any trouble falling asleep if I go to bed at 10, I just often find it hard to be ready to go to bed at 10.
But my main point! You asked about experiences that would shed some light on if this delayed sleep cycle would be true in a pre-agricultural society.
Several years ago, I stayed at a shamanic retreat center in the Peruvian Amazon, for 3 weeks. In this center, we all had our own little huts, and there was no electricity anywhere except in the kitchen. So, all we had for light in the evening was candle light. Evening would come on between 7 and 8. I would often stay up for another hour, until maybe 8:30 or 9, and then would go to sleep, no problems. And every morning, I awoke at dawn. It was a very unusual experience for me, since I have NEVER been the type to awaken within even 3 hours of dawn.
When I returned to the states, this trend kept up for a short period of time, but eventually I returned to my old pattern.
So, from my experience, I would say I agree with you, that this is just about some of us being more sensitive to light cues. I know I keep the lights on in my place quite low at night, I can't take a lot of bright light. And in the morning, I HAVE to have light to come into my room, otherwise I can't wake up. That's why I will never do the black out curtains that some propose, because otherwise I won't wake up until 2 in the afternoon.
Hope that helps!