It’s that time of year again: November 24th is N24 Day. If you read my blog for autism information, you’ll want to keep reading because N24 is roughly three times as prevalent among Autistic people as in the general population. And if you read my blog to get to know me better you’ll definitely want to keep reading because N24 is my most challenging disability (and I am deeply and pervasively challenged by living Autistic in a world not build with our needs in mine.)
N24 is short for Non-24-Hour Sleep-Wake Syndrome which has many other names including free-running sleep disorder and hypernychthemeral syndrome (I will happily pronounce that last one for you if we ever meet in person and you remember to ask me.) N24 is a circadian rhythm disorder (CRD) and it has “sleep-wake” in the name, but it’s about so much more than sleep. Sleep is the most obvious marker of the disorder so that’s what it gets identified by and what it’s named after, but it affects the body on deep, systemic levels.
Here’s the nutshell scientific description. I’m keeping it as short and sweet as I know how to:
In the center of your brain, there is a region just above the optic chiasm (the place your optic nerves run through on their way to the visual cortex at the back of your brain.) That brain region is named by its location rather than its function: the suprachiasmatic nucleus. The short name is the SCN.
Your retina is the “movie input” for the imaginary visual theater in your brain. Light comes into your eyes and the rods and cones on your retina translate that analog information into electrical impulses that pass through neurons on their way to the visual cortex where they’re interpreted (and the image, which becomes flipped on the way there, is corrected again so things that are right side up look right side up to our perception.) Many of you reading this were privileged enough to learn this information in high school (or even elementary school for some) but others may never have learned about rods and cones and how our nervous system works to allow us to see. So I apologize if I’m going over well-worn territory and you’re bored. I’m trying to get everyone on the same page.
So there’s another type of sensor on your retina that you probably never learned about unless you studied university-level biology. I’m not even going to bother with the long name because I’d have to look it up and it’s not that important to this story. So we’ll just stick with their nickname: ipRGC cells. (I might even have the capitalization wrong on that, but I’m stubbornly not going to look it up.)
The ipRGC cells are pretty special and there are some amazing experiments that have been done that show that many people who are 100% blind and can’t even see light and dark still have intact ipRGC cells that are doing the job they evolved to do. These neurons have super long axons that go all the way from the retina to the SCN in the center of the brain. And we’ve found one specific function of the ipRGC cells (though they probably do lots of other things I’m not aware of, like most body parts) which is that they recognize light (the ipRGC cells are found in their densest clusters on the parts of the retina that are most exposed to the sun when we are walking around outside) and tell the SCN about it.
That’s it. Even if our rods and cones are damaged or absent, so long as we have ipRGC cells we can “see” light and the SCN knows when day and night are happening and does its work accordingly.
Now you might ask me, why is it so important whether my SCN knows if it’s day or night? I’m glad you asked (even if it was a pretend ask that I just typed myself. You probably actually don’t care. Or I guess you marginally care or you wouldn’t still be reading.)
Every cell in your body has a clock in it. Even your blood cells have internal timekeeping mechanisms that have been shown to continue to respond to day and night in a laboratory after being removed from your body to be studied. Cells are tiny, though, and there’s not a lot of room in there for complicated “machinery.” The clocks in your cells are only as accurate as they need to be. They’re like those wall clocks that are designed to periodically talk to the “atomic clock” the Navy keeps. A radio signal broadcasts the most accurate time we have and your wall clock tunes in to that feed and nudges its own display regularly to reflect accurate time. The clock only needs to be vaguely accurate and check in with the radio signal often to make it a highly accurate clock.
Your body’s cells are the same way. They have clocks in them but they’re so-so. They’ve evolved to check in regularly with the SCN, which knows what time it is, to keep your body synchronized.
While bodies are always working to maintain homeostasis (a balancing act that requires different glands and organs to secrete precise amounts of hormones and other biochemicals.)the human body is not static. One example of homeostasis in action is when you eat a piece of chocolate cake and, if your pancreas is functioning properly, your body secretes insulin to escort all that sugar into your cells where it can be converted to the fuel your body runs on.
One example of the body not being static is that you have a different amount of cortisol when you wake up compared to when you go to bed. (Cortisol is usually referred to as a “stress hormone” but that can be a little deceptive because you’ll be way stressed out (and chronically ill) if your body doesn’t make enough cortisol (any cortisol at all.) That’s called Addison’s Disease.) Someone without a CRD will usually have the most cortisol upon awakening (to rouse you and stir you from sleep) and, unless they’re under a chronic, unhealthy level of stress, cortisol will usually reduce through the day.
So your body is always changing what it’s doing and cycling through different hormonal routines. All of this is precisely timed and regulated by responses to stimuli — in other words, your body reacts when things happen to it. Some of those things are obvious: like eating the piece of chocolate cake. Some of those things are almost TOO obvious: they are things that are so much a part of your environment you might never actually think about them. One of the biggest stimuli — one that has ruled life on this planet for as long as there’s been life on this planet — is the light of the sun.
One way to measure light is lux. Lux is a measurement that combines brightness and distance. I spent thousands of dollars on therapy lights and still was only able to produce a tiny fraction of the lux our eyes receive when we’re sitting in the shade of a tree on an overcast day. The sun is bright and in the sky all day and not only does it let us see what’s around us, but it also regulates what our bodies do. Some mammals are mostly awake at night and sleep during the day. Others (like mice) are crepuscular. That means they are most active at dawn and twilight and chill during the darkest dark and the brightest light.
Humans evolved to be mostly diurnal – awake at day and asleep at night. Yes, it’s not that simple. In the winter when nights are very long, humans who do not live with electricity (and thus no artificial lights to affect their SCN) tend to go to sleep earlier (because it gets dark earlier and dark triggers sleepiness in ways I will probably explain before I’m done writing this) and then wake up for a few hours in the middle of the night before going back to sleep for the second half of the night. If you do that and you live with electricity you are probably not experiencing that natural mid-sleep awakening. You are probably being disrupted by artificial lights, especially if you wake in the middle of the night year-round and not just in the darkest part of the winter.
Also, even without artificial lights, some people have an easier time in the morning (larks) and some have an easier time in the evening (owls) while the vast majority of people living without electricity will naturally wake at about the same time, early dawn. We have so many more night owls now than humans did historically because we live with artificial lights that have disrupted our circadian rhythms and the way our bodies’ timing system works, adding artificial light will make people into night owls, not into larks. Light keeps us awake because the ipRGC cells (which have tuned into blue and part of the green section of the light spectrum because the sky is blue and the sun is green (I know it looks yellow. That’s the effect of the atmosphere. I took a terrific astrophysics class from Dr. Ronen Plesser and one thing I love about how he teaches is that rather than tell you something cool about astronomy he has you do problem sets and teach yourself the cool stuff by discovering it through the calculations. I did the math and the sun is most definitely green.)
When we see blue/green light (which is mixed in with all the other colors in those white light bulbs we light up the night with) the SCN tells the brain to mop up the melatonin. Melatonin is a hormone that, among other things, helps you feel sleepy. That’s why dark makes you sleepy. It’s not the dark per se. It’s the absence of light from the blue-green spectrum. Using a purely red or amber light should allow your body to become sleepy as well if you are producing melatonin and no blue/green light is leaking into your red or amber light. That’s why a campfire won’t typically keep you up all night: not enough blue/green light in it to wipe out your melatonin.
But the SCN does more than just help you wake up and go to sleep. Remember all those cellular clocks that don’t keep perfect time? Without the “atomic clock” they will drift farther and farther away from the actual time? Your SCN is that atomic clock. Every cell in your body talks to the SCN. It’s a busy place. And when your SCN is confused, your entire body gets confused. It’s why studies show shift workers getting fatter and sicker on their work schedule – their SCN is struggling to keep up and their body literally doesn’t know what time it is. Hormones like ghrelin and leptin get out of whack. The stomach is not prepared to digest at mealtime. The pancreas doesn’t know which way is up and loses grip with its cycles and reactions.
Now back to what N24 is. Most people who have N24 are completely blind. They have N24 because they don’t have retinas. One example is an acquaintance, Eric, who had an infection that required his eyes to be removed. Now he has N24. I am not blind and I do appear to have functioning ipRGC cells, but detective work insinuates that the root of my N24 is my SCN, probably not my ipRGC cells. I say that because when I sleep outside and wake up with the sun and don’t go indoors until noon, my SCN starts functioning the way it is supposed to. When I live indoors I just can’t get enough light into my eyes for my brain to work the way it’s supposed to.
A freelance journalist wrote an article about me and my choice to live in my car in order to get the amount of sun I need in order to function: http://www.sparrowrose.com/2015_SeptOct_SciAmMind_circadian.pdf
So…. what happens to my body when I live indoors with the lower level of daytime light and much higher level of artificial evening light? The first thing that happens is I start to have “insomnia” and “excessive daytime sleepiness”. But that’s not actually what’s happening.
Think of your circadian rhythm like a conveyor belt. Your body is on a sort of long treadmill, moving through the cycles of the day. When you are in sync with the 24-hour day you probably wake up in the morning, get ready, go to work or school, hit a late afternoon slump, get a second wind and do fun things with family or friends in the evening, then go to bed and do it all over again the next day. You might stay up a little too late sometimes and maybe you always grumble when the alarm clock goes off. You might even be tired all the time because you keep staying up a little too late and stretching yourself a little too thin.
But you keep getting up and going to work every day because your circadian rhythm is like a thick rubber band. You can stretch it by staying up too late or setting the alarm earlier than your body wants to get up, but the stretchy band keeps snapping back into place. Maybe you don’t have any patience for people who are late or miss things because you know how hard it is to stay in a routine but, goshdarnit, you put in the effort and deal with the suffering and get it done so anyone else who doesn’t do that must be weak and undisciplined, right?
Except some of us have broken brains that have turned our stretchy rubber band into something stiff and rigid, fragile, easily broken and hard to restore. There are two aspects to a CRD: your sleep is not happening at the time you want it to happen (and/or happening at times you don’t want it to) AND there is a rigidity that it’s futile to fight. I’ve fought (and lost) that battle and after a few times of getting so sleep deprived I was hallucinating and a few times of nearly accidentally killing myself by falling asleep while driving I’ve learned to respect the rigidity and respect that the Sleep Monster is stronger than I am.
So my “conveyor belt” is broken. In me, that looks like I still have a conveyor belt but instead of being 24 hours long it’s something like 26 hours long. When I don’t live outside, I come unmoored from the 24-hour day. I start to slip around the clock because my conveyor belt is set to the wrong speed. And my body’s cells get confused and start desynchronizing — for example, my immune system might think it’s 7 am while my stomach thinks its noon and my pancreas thinks it’s 3 am. When I am living outdoors and synchronized, I take 10 units of insulin per day. When I am living indoors and desynchronized I take over 30 units of insulin per day and still have what’s called “brittle diabetes” which means I’m always dangerously high or dangerously low and on a roller-coaster between the two with no real control. It’s miserable and deadly.
I get depressed and angry when I’m desynchronized, mostly because I feel so awful on such a deep, systemic level that I can’t even identify “what hurts”. Basically, everything is shit when I’m desynchronized. It takes days to recover from, as well. And the worst part is that my entire connection to humanity falls apart. I can’t even make it to a doctor’s appointment when I’m desynchronized, let alone get to work or class. I learned I can’t even maintain a synchronous (like real-time chatting) online friendship because I can’t be awake consistently during the times my friends are awake. If I meet night people while I’m awake at night, I will continue to shift around the clock and not be able to see them for weeks. By the time I “come back around the clock” they have decided I abandoned them and moved on to other people.
So there’s my annual contribution to N24 Awareness Day – a rambling, stream-of-consciousness discussion about what I live with. There is no cure for N24. Evidence points to it being a genetic condition. I am forced to live in specific ways and with specific routines or the entire world falls apart and I can’t function. My circadian system is almost unbelievably delicate and it doesn’t take much to upset it. I can’t live with people. I can’t sleep with a lover. When I go to multi-day conferences I have to miss out on so much because I can’t spend three days in a dark hotel conference room watching powerpoint slides and my evenings in brightly lit hotel bars and dining halls. I have some laser goggles that filter out all the blue and green light but I hardly use them anymore. I had an evening class with a professor who thought it was really funny to use the red markers on the whiteboard and laugh about how I couldn’t see what he was writing (I could have easily seen blue or green markers as they would have looked black through my goggles.)
Being Autistic can be tremendously isolating and I do experience that. But my N24 makes me far lonelier and feel far more isolated. I can find people who appreciate Autistic people. I’ve never yet found anyone who appreciates N24, let alone anyone able and willing to bend their life the little bit I would need someone to bend to meet me.
Many of us Autistics complain that we go 95% of the way and meet neurotypicals unwilling to go that 5% because they insist that we should meet them half-way…not realizing how far we’ve already bent to get on that bridge between our neurologies.
With N24 I feel like I’ve gone 250% of the way and no one sees that because it’s still not enough for me to mesh with “normal society” (and I haven’t yet found an “abnormal society” that could be a social home for someone with N24.) Even dating someone else with N24 was a challenge because we were dealing with TWO people’s sets of restrictions and then when one or both of us lost entrainment and became desynchronized we’d often be on different cycles, chasing one another around the clock like a dog chasing his tail and never catching it.
Being Autistic can be lonely, but I have a huge “Neurotribe” and many dear friends within that group. Having N24 is what it’s like to be a “tribe of one” — isolated, alone, misunderstood, and struggling to survive in every sense of the word.
And now, if you have read this far, you are so much more aware of N24 and the devastating effects it has on a person’s life. Thank you for listening.