I have a circadian rhythm disorder. Not long ago I free-ran at 25.5 hours for several years. Advancing by 1.5 hours per day, you're making adjustments to the world around you ever two or three days. Endlessly. I would have mortgaged a minor limb to change my rotational period from 17 days to 21 days. Just to be able to stay in a consistent phase with the day of the week would have been a major blessing.
I had previously tried melatonin with mixed success. At best, having exhaustively worked through many doses and times, it seemed to reduce my period to 24.25 hours, a little less than 2 hours per week. This is no bed of roses, either. And the melatonin was taking a three hour chunk of out every evening where I was yawning like a date-raped hedgehog waiting impatiently for a fresh coat of paint to dry in his homey bungalow, listless and unable to anything more complicated than cook dinner—usually a fairly simple dinner.
Recently I tried melatonin again in a sustained-release formulation (newly discovered at retail) and this magically worked much better. At a large dose, I'm able to stay on a 24-hour day permanently, over very close to it. The daily date rape continues to suck.
At lower doses—minus the daily date rape—I seem to stay near a 24-hour day, with unplanned excursions when it all comes unglued. This might well be addressed by further tweaking. I've ever so close now to having the best of both worlds.
The operative parameter with circadian rhythm disorder is that there's no such thing as "merely" a flesh wound for a haemophiliac. My clock drifts because there's something broken in the entrainment circuit. A haemophiliac bleeds because there's a gash or puncture or rash, but he continues to bleed because the blood chemistry required for blood clotting is MIA.
A normal person experiencing severe jet lag (say a trip to Japan or Australia) is in a horrible, unpleasant, barely functional place. In my metaphor, you feel weak because you're gushing blood. In this state, your clotting reflex (if you have a clotting reflex) is actually on overdrive. The stress is horrible, but the body is rapidly adapting and compensating. If you make it through the first day, you hope the second day will suck a little bit less, until after a few days, it hardly sucks at all, then you're body finishes making the adjustment, and everything becomes normal again.
For a person such as myself trying to maintain a 24-hour day without melatonin, the process goes the other direction. Light jet lag turns in moderate jet lag, and moderate jet lag soon becomes severe jet lag, and severe jet lag soon gives way to waking hypnagogic hallucinations. Every one of my attempts to force myself into adherence with the 24-hour clock on will-power alone developed along this path over two weeks. I was as cognitively impaired at this point as that time I got a bit too carried away in a bout of binge drinking, to an extent I never repeated again. And still the bleeding continued. By this point your will-power is so diminished, you need a jeweller's work bench and a steady hand to make even the smallest life decision. You know you're suffering like hell, but you've almost forgotten what crazy notion drove you to try maintaining a 24-hour waking day.
From French invasion of Russia:
The cold was so intense that bivouacking was no longer supportable. Bad luck to those who fell asleep by a campfire! ... One constantly found men who, overcome by the cold, had been forced to drop out and had fallen to the ground, too weak or too numb to stand. ... Once these poor wretches fell asleep they were dead. If they resisted the craving for sleep, another passer-by would help them along a little farther, thus prolonging their agony for a short while, but not saving them, for in this condition the drowsiness engendered by cold is irresistibly strong. Sleep comes inevitably, and to sleep is to die. I tried in vain to save a number of these unfortunates. The only words they uttered were to beg me, for the love of God, to go away and let them sleep. To hear them, one would have thought sleep was their salvation. Unhappily, it was a poor wretch's last wish. But at least he ceased to suffer, without pain or agony. Gratitude, and even a smile, was imprinted on his discoloured lips. What I have related about the effects of extreme cold, and of this kind of death by freezing, is based on what I saw happen to thousands of individuals. The road was covered with their corpses."
Yes, all my forcible 24-hour experiments ended at some point in the third week when I would blindly stagger into my bed with the hint of a smile upon my discoloured lips. The only difference is that after a sixteen-hour sleep of the dead, I actually woke up again feeling like a million bucks. When I used to bike tour, I would become so ravenous that a simple peanut butter sandwich would taste like nectar of the gods. This was like waking up after your best sleep ever, multiplied by nectar_of_gods / peanut_butter.
The cure for people who lack the cognitive equipment to distinguish bleeding from haemophilia is Insomniac by Gayle Greene (520 pages, 2008). Gayle is a professor of English with a Ph.D. from Columbia University. Somehow she's managed to stay employed at a high level despite her intractable sleep disability. I admire her grit. Think Mattie Ross bunkered down in a survival shelter for thirty years to outlast nuclear winter.
Some of the feedback on this book suggests that the author is a sharp-tongued and doth protest too much. Somehow I imagine that most of this criticism comes from the same people who regard the loss of yet another 1/2" of leg room in cattle class as being worth a half-hour bitch session with their seat mate. I have a feeling Mrs Greene's sustained snark—sleep loss affects the mood like PMS on steroids, that's the whole point of her book—quickly becomes hard to bear for people who enjoy complaining about minor things.
What does the Lubyanka, Hanoi Hilton, and Abu Ghraib all have in common? Sleep deprivation. Tough customers who are willing to endure the physical abuse, soon discover that extreme sleep deprivation dissolves your identity and spirit from the inside out (taken too far, it ultimately destroys your thermo-regulation, and then you die).
Case 0: Your body gets used to the 24.7 hour day, with no physical symptoms. Whatever zeitgebers are influencing your body clock are sufficiently strong to achieve normal entrainment to a abnormal entrainment period.
Case 1: The extra forty minutes gives you a mild case of jet-lag, but the jet-lag causes your body to adjust proportionately. Maybe a permanent state of mild jet-lag is just the cost of doing business on a 24.7 hour day.
Case 2: Your body fails to track the lengthened sleep period. You go in and out of jet lag on a week by week basis as your internal body clock syncopates with your sleep routine.
Case 3: Your body fails to track the lengthened sleep period, and the constant stress drives your sleep clock into some horrible non-state that never abates.
Case 3A: You somehow managed to cope with this by adopting a fragmented, irregular sleep routine (best attempted by those under the age of thirty, when energy reserves are high enough to ride the dips out).
Case 3B: You don't manage to cope with it, and become permanently trapped in hazy zombie gulag house of mirrors (stress-induced haemophilia).
Next we have the orthogonal matter of whether your sleep routine tracks your living environment, of whether your sleep routines syncopates with your living environment.
Case 0: Sleep and environment track together. You might or might not suffer from the length of the circadian day imposed upon you, but at least if you are suffering you can make stable plans to work around your suffering.
Case 1: Your sleep might track the rotation of Mars, but the living environment on Mars marches to its own drummer (like the submarines some have mentioned). Every you wake up with a different orientation to the environment around you. If you're bleary, weary, and far from your best from the moment you awake (and for much of the day) this is an extremely challenging environment to live within.
Case 1A: The daily drift is smallish, maybe an hour a week or a little more. You'll have enough stability in your routine that the changing phase can be managed incrementally.
Case 1B: The daily drift is large, 20 to 40 minutes a day. You'll be able to adapt incrementally, but you'll be aware of having to manage this all the time.
Case 1C: The drift is huge, 40-70 minutes a day. You'll think consciously about the phase-of-the-day first thing on waking, last thing on retiring, and at every meal time in between. It will be Monday morning, and you'll think back to Monday morning from the previous week like a time when you lived in an entirely different country. You'll probably buy a Pebble watch and program it to constantly display your internal body clock as well as the local time the coordinates your living environment.
Case 1D: The drift is stupendous, 70 minutes or more a day. Not only will you buy a Pebble watch and program it yourself with a custom calendar for a "market of one person" (Gershenfeld). You'll create strange names for each and every phase relationship, so you can keep track of your incessant daily adjustments cycle over cycle. You'll be overheard muttering to yourself "it's the third day of the spider, Brumaire the seventh" and people will think you just teleported onto planet earth from the Second Revolutionary Epoch of the Ferengi Reformation. If you're the conscientious type, you'll experiment with prescription amphetamines. This will help to some degree, while drawing you into whole new vistas of personal weirdness, which you'll welcome with open arms because you're so damn fed up with the incessant, all-too-familiar weirdness. (If you're not the conscientious type, your medicine cabinet will soon resemble the pagan love-child of Glenn Gould and L. Ron Hubbard).
Nothing in life is quite as important as you think it is while you're thinking about it.
— Daniel Kahneman
There's an interesting corollary to this wonderful gem of wisdom. Nothing adds up as fast as a circadian drift of five minutes per day when you stop thinking about it.
When you really live with a condition like this, if it's mild, there's this tendency to start thinking about life issues, like the recent fight with your bunk mate, and forget about your small problem.
Just five minutes a day sustained for five weeks—e.g. a thrilling library book you've already renewed once because you never even got around to cracking the cover by the time the original due date rolled around—turns lunch into breakfast.
People get this all wrong because they think in terms of homeostatic jet lag (i.e. jet lag minus the haemophilia term). And they get this wrong because they forget that time soon slips by in months, seasons, and years. Finally, people get this wrong because they don't think clearly about whether the period stress lies within the zone of biological accommodation, or lies outside the zone of biological accommodation (and when it lies outside the zone, whether the stress is ignored or induces the entire system into chaos).
The SCN is actually a complicated little thing. Here's a recent paper (2014) which provides a good starting point for anyone interested in the literature.
The clock shop: Coupled circadian oscillators Here's a paragraph extremely interesting to me, personally, as I have not before encountered the GABA pathway:
Decreasing GABAergic tone by genetically deleting the Na(V)1.1 sodium channel leads to impaired communication between the ventral and dorsal SCN and, intriguingly, a longer circadian period. Furthermore, pharmacological blockade of GABAA receptors or reducing GABA release with Na(V)1.1 deletion decreases the ability of the SCN to adjust to shifts in the light cycle, presumably by impairing communication between ventral and dorsal SCN. Thus, GABA appears to play an important role in long-range, rapid synaptic communication in the SCN to facilitate entrainment to environmental cycles.
I'm pretty sure part of my problem is that normal light-cycle entrainment has almost no effect on me. I've even used the Philips goLITE BLU (what sleep-deprived marketing drooloid styled that handle?) Light exposure when I'm sleeping does, however, substantially reduce my sleep quality; and white light exposure late in my circadian day does increase my latency to sleep onset. Phase effects? Forget about it.
In electrical engineering terms, coupled oscillators can exhibit degenerate coupling modes (usually where one flips over, and the coupling phase changes by 180 degrees). This was recognized from the mathematical model, then a light/dark stimulation program was devised to see if it could be triggered in an animal model (hamster is what I recall), and it was actually observed. (I haven't looked at that paper for years, so I'm rusty on the details.)
As I presently understand it, the SCN is actually just a reference clock. Nearly every tissue in the body contain local "clocks" that govern gene expression patterns. Most of these local clocks are coupled to the global reference clock, so the entire system stays on Moscow Standard Time. This prevents the liver from going into a metabolic housekeeping cycle right before the main daily feed.
The brain, in particular, does an immense amount of housekeeping. When all this housekeeping is coordinated (aka consolidated) we call this "sleep". Mess up the sleep program badly enough, and different subsystems in the brain begin to schedule housekeeping pretty much at random—including while you're wide awake. The sleep expert James Maas has some online talks where he discusses microsleeps and the neurological function of sleep spindles (recently discovered, and extremely interesting).
Also recommended is The Family That Couldn't Sleep: A Medical Mystery by D. T. Max. This book is not quite what it pretends to be.
First, members of this family sleep just fine until they reach a certain age. In this respect the condition resembles Huntington's disease. Then because of what is now believed to be a prion disorder, their ability to regulate consolidated sleep goes MIA. The afflicted quickly descend into a personal hell, and die without fail inside of two years. The meat of this book, however, concerns the scandalous history of breeding in and in and its probable contribution to "mad cow"-ish diseases in modern livestock. (Like the fat slav Mengele threw into an ice-water swimming pool who survived for forty-two minutes[*], prions laugh at bleach or steam for a long time.)
[*] Research shows that forty-two percent of all statistics are made up on the spur of the moment.
WARNING: The above book is not suitable for deregulationists (NSFD). There is, however, a fat chapter devoted to an alleged, convicted, and largely self-confessed pervert who pursued his deviance on an epic canvass.
Finally, the commonly-accepted 25-hour circadian day is complete hogwash. As I recall it, the original experiment erred in not sufficiently reducing ambient light. Sensitivity to low light levels was not properly understood. All recent research places the endogenous rhythm at just a hair over 24 hours.
Bah, I just typed so much I can't be bothered even to skim it for obvious errors.