Dawn simulation

Dawn simulation works by gradually turning on a light, generally 40w or 60w, over a period of time, most typically 30 min, in order to simulate a sunrise.  The light goes through your eyelids and moves your sleep stage to the point where it should wake you up naturally, meaning that you wake feeling as refreshed as you’re going to get and that hormones such as cortisol do what they’re meant to.  I find that when it wakes me up, it feels like I blink and I’m awake, rather than being dragged kicking and screaming into consciousness.  They all have backup alarms you can set just in case.  Most people don’t need them, but some do, and can still find that while the light isn’t quite enough to wake them up on its own, they do feel much better when they wake up.

As well as making it easier to get up in the morning, some research has found dawn simulation to be as effective or nearly as effective as bright light therapy for treating SAD, and it may work well for non-seasonal depression too.  This is despite the fact that it doesn’t use such bright light, just an ordinary bedside lamp or equivalent.  It’s thought to be something to do with the gradual increase in light having the effect.  The advantage over bright light therapy is that the treatment is over by the time you get up, you don’t have to tether yourself to a light box in the morning, but the disadvantage is that it may not be as effective.  Companies selling both tend to recommend it for mild SAD and bright light boxes for more severe SAD, I’ve noticed.

Dawn simulators also generally offer dusk simulation as well, where the light fades down gradually to help you get to sleep.  I think there’s some research around showing that it helps a bit with insomnia.  I’ve not really used this setting much as it’s less convenient, though I find it relaxing when I do.  I use dawn simulation because it helps stabilise my sleep pattern even further, and because it helps both myself and my partner to get up in the morning.

One common problem with dawn simulators is that they tend to buzz when the light is ramping up or down.  The best solution is to get one of the new energy-saving halogen bulbs, also called halogen incandescent, which are the same shape as standard incandescent bulbs and can be dimmed.  Not only will they save you at 30% on energy (42w is equivalent to 60w and so on, though I and many other people think they actually seem to be brighter than that) and last longer, but the light is good quality and they don’t buzz.  You can’t use fluorescent bulbs in a dawn simulator (I never recommend them anyway as the light causes problems for so many people), you can’t use the usual halogen bulbs, you can’t use LED bulbs if you’ve managed to find one, you can just use them with standard incandescent or energy-saving halogen.  This is for where you put in the bulb yourself: there are a couple of types of dawn simulator around using fluorescent or LED lights already built in.  If you get the type of dawn simulator which plugs into a lamp, again it has to be the sort of lamp which takes incandescent bulbs, and it can’t be a lamp which already has any sort of dimmer fitted, such as a touch lamp.  Just use an ordinary table, bedside or desk lamp.

There’s a new type of dawn simulator which is combined with a lightbox, such as this one (do read reviews, there are some poor quality ones out there by other manufacturers).  They may be a good solution for people wanting to try both dawn simulation and bright light therapy, but bear a few things in mind.  Firstly, it comes up to full lightbox brightness rather than the brightness of a 40w or 60w bulb, so that you will most likely be awake long before it’s anywhere near fully bright.  One solution could be to set a 90 minute sunrise and assume that you’ll be awake after, say, 30 min.  You need your dawn simulation to be by your bed but are unlikely to want to be using your bright light box by the bed, though if you read in bed in the morning or have your laptop close to your bed you could be OK.  The other point that occurs to me is that since the light is much brighter than is needed for dawn simulation, you could place it further away from the bed (e.g. by your computer, if it’s in the bedroom) and just point it in the right direction.  If I was starting light therapy all over again, I’d probably have gone for one of these and hoped that I’d be able to work something out once I’d fiddled with it enough.

I started off years ago with an all-in-one Bodyclock by Lumie where the lamp is built in, but even though it was a 60w bulb I found that it wasn’t bright enough for a reading lamp, plus Lumie often get slated for poor product build quality.  I sold it on eBay and bought myself a Sunrise System which plugs into a lamp or lamps of your choice, and vastly prefer it.  Mine  eventually became faulty and I sent it in for repair, where they reported that it had been damaged by a power surge (at which point I promptly bought a surge protector) and sent me a replacement which is slightly different from the older model.  They can take a bit of getting used to, and I think the company needs to continue tweaking them (though at the very picky level), but generally they’re excellent.  They have lots of useful features, such as being able to set the time individually for each day of the week.  We have it set to finish at 9 am Mon-Sat and 10.30 on Sunday, when my partner starts work later.  Actually he starts quite a lot later on Sundays, but I want to keep myself in a good routine while having a bit of a lie-in.

One of the great things about dawn simulators of this sort is that you can plug them into more than one lamp as long as you don’t exceed the total wattage, which in the case of the Sunrise System is 200w in the US and 300w in Europe.  That’s enough to hook it up to lights all over the bedroom if you like, though most people like to hook it up to a light on each side of the bed.  We’ve found that I get woken up better than my partner does by light, that he doesn’t like waking up to full light and generally prefers it to be dimmer on his side, that he still needs his alarms as he’s trained himself to respond to those, and that I take longer to get up once I’m awake, so that by the time he’s had a shower and got ready for work it’s about the time that I’ll be getting up.

So on my side of the bed, the dawn simulator is hooked up to my bedside light, which is a 40w equivalent low-energy halogen bulb in an anglepoise lamp that faces the wall, and on my partner’s side there’s a little 25w spotlight hidden behind a vase which points into the corner and is enough for ambient lighting.  My partner’s bedside reading light is independent of the dawn simulator.  The dawn simulation starts at 8 am, which is when the first of his three alarms go off.  He gets up at 8.30 when the light is up to half brightness, and I get up at 9 when the light is at full brightness.  As there are alarms going off from 8, I can be anywhere from awake to dozing to having fallen asleep again while the light is increasing, but it doesn’t seem to prevent it from being effective.  Occasionally I sleep in later than 9, but it’s probably only once a week, which for me is fantastic.  This helps keep my sleep stabilised even if I went to bed too late the night before.  I’m getting up earlier than I used to (even when I was using the lightbox), and it’s great being able to get up earlier in the morning and go to bed at the same time as my partner.

Bright light therapy

This is best known for treating Seasonal Affective Disorder, where it has been found to be as effective as anti-depressants, although the most effective treatment of all is to combine light therapy with anti-depressants.  What is less well-known is that bright light therapy is almost as effective in non-seasonal depression and is extremely useful for circadian rhythm disorders.

The main myth about bright light therapy is that it’s about full-spectrum lighting. It isn’t.  There are quite a few myths about light therapy which have been set up by rivalrous product manufacturers, and this one is an attempt to sell certain fluorescent lightboxes by claiming that they are in some way better than the others, which has somehow turned into the myth that all you need is a standard full-spectrum bulb.  The most effective wavelength for resetting the circadian clock is 470nm, blue light, so you need either blue light or white light which has plenty of blue in it.  (A couple of manufacturers favour green light for rather complicated reasons which you can read about here, where it’s concluded that they’re not worth trying unless you are at high risk of maculuar degeneration.)  The other important thing is the intensity of the light.  When a traditional fluorescent lightbox is used, 10,000 lux is preferred, though there are a few models around which use 5,000 or even 2,500 and require proportionately longer usage times.  Merely installing a full-spectrum/natural daylight bulb into your domestic light fittings will not make a blind bit of difference, as the light isn’t anywhere near strong enough.  Full-spectrum bright lightboxes were probably introduced because so many people find fluorescent light to be visually unpleasant, and there is a demand for a better colour temperature.  If you are going for a fluorescent lightbox, you may want to see if you can view a normal and a full-spectrum version to find out if you do prefer one or the other, but to be honest I think very few people are bothered about this, and that you’re better off using an LED lightbox if you don’t like fluorescent light.

Lightboxes are used for periods ranging from 15 min to 2 hours, depending on the type and the patient’s needs.  Unless you have Advanced Sleep Phase Syndrome, where you fall asleep too early in the day, the usual time of treatment is first thing in the morning, just after you get up (which for some people isn’t actually morning!), whether this is for sleep disorders or depression.  If you have DSPS or Non-24 Sleep-Wake Cycle, using bright light therapy in the morning has a high chance of stabilising your circadian clock and can even move it backwards so that you are falling asleep and waking up earlier.  I found that using a bright light box just after awakening immediately stabilised my sleep pattern at 24 hours instead of the 25 it had been on for years, and I started this four and a half years ago.  However, if my bedtime and waking time were too late, I needed to combine bright light therapy with a few days of sleeping tablets, taking the tablets an hour earlier each evening.  After that, the morning light therapy would serve to keep my waking time where it should be.  This has worked pretty well for me, although my sleep pattern wandered out of synch a few times a year and needed to be chased back.  Adding darkness therapy into the mix seems to have stabilised it completely.

There are two main types of lightbox, compact fluorescent and LED.  Fluorescent are the traditional ones and have been around for longer.  They are larger, require a longer treatment time, produce white light, and may cause medical problems for people sensitive to fluorescent light, such as migraine, visual problems, dizziness and so on.  The manufacturers try to dodge here and say that they have better ballast, but in my experience they’re just as bad as strip lighting and can cause nasty migraines. Perhaps they are better constructed, but since the light is so much brighter and it’s right by your face, it’s still more than enough to cause problems if you have difficulty with fluorescent light.  On the other hand, because they’re larger and the light is not as directional as LED light, they permit a little more freedom of movement when you are in front of them, though you still can’t move far away.  The light is also more likely to end up in the optimal position above your eyes, though since fluorescent lightboxes take much longer to use than LED lightboxes despite this, the advantage is probably cancelled out.  When looking at the stats for a fluorescent lightbox, most will say that they produce 10,000 lux, but you should also check at what distance that measurement is accurate.  If it’s 10,000 lux at 20 cm, that’s far too close to the light to be comfortable.  60 cm is more sensible, or alternatively just realise that you will need to use the lightbox for longer.  I think that this is how manufacturers are getting around the problem that everyone is told to look for 10,000 lux, but no one is quite sure what it really means and don’t realise that it’s only the measurement of the light intensity at a certain distance.

LED lightboxes have been around for a few years and may produce either white or blue light, which you can read more about here.  They are smaller and require a shorter treatment time.  Not everyone gets on with coloured light, and as the LED panel is composed of lots of little LEDs that look like dots, some people report getting spotting in front of their eyes, although I suspect that they were using the lightbox incorrectly.  You’re not meant to stare into it, you’re meant to position it at the side, or even better above your eyes, so that it hits your peripheral vision. LED lightboxes do have the disadvantage of needing to be placed more exactly and requiring you to stay in the same position, as the light produced by LEDs has a very narrow beam angle.  I use mine by my laptop or while sitting at my sewing desk, and while sometimes I need to prop up the lightbox to get it at the right angle, after that it’s fine.

I have a GoLite, previously made by Apollo and now made by Philips, which is a blue LED lightbox and very highly thought-of.  I also have a Lite-Pad, which is a cheap white LED lightbox I picked up on eBay for a tenner.  I use this one by my sewing table to save messing around with cables when I want to quilt during my morning lightbox stint, and also so that it doesn’t affect my colour judgement.  The GoLite does have a lot more bells and whistles, such as a clock and the ability to set both the light intensity and the length of time for up to three different preset programmes, but you’re paying a lot for them.  The Zadro looks like the best of the cheap lightboxes if you’re in the US, and indeed looks like a very good lightbox in its own right.  You can also buy combination lightbox/dawn simulators, of which more later.

There’s another type of bright light therapy around, known as the light visor, where the unit is placed in a sort of cap worn on the head, and the light is shone into the eyes from above.  Lumie makes a few, and there’s one which produces blue-green light around.  Their one advantage is that you don’t have to be tethered to your lightbox, you can move around.  Psycheducation.org is doubtful about them, and I agree.

Since you can’t tell which lightbox you will get on with in advance, or even if it will work for you, and since these things are very expensive, find a company who will offer either hire-purchase (e.g. the National Light Hire Company) or a free trial (e.g. Lumie).  You may need to spend a while working out the right amount of time to use the lightbox for.

Of course, an entirely free alternative is simply to make sure you get outside for at least one hour every morning.  It doesn’t matter if it’s cloudy.  I’ve run into a woman online who managed to get the same effect by using a 150w fluorescent light (that’s actually 150w, not the equivalent to 150w incandescent), such as this grow light, in her overhead light during the whole day, not just for an hour.  This is far, far brighter than normal domestic lighting, and while it won’t save you energy and many people (especially with ME) will find it uncomfortable on the eyes and/or likely to provoke migraine, for some people it’s a good solution.

Another possible solution is to buy an LED bulb in white or blue and sit with it at a level just above your eyes for a couple of hours a day.  The blue bulb will be exactly the right wavelength, and while the white won’t have as much blue, white LEDs peak at the right wavelength so it will have a lot of it.  It won’t be as strong as a therapeutic lightbox but if you use it for long enough and keep it close to the top of your eyes, you may be able to get a decent result out of it.  If anyone tries this, do let me know how you get on.  I’ve got one of the blue bulbs which I’ve used for experimenting with moonlight simulation (this is popularly known as Lunaception and is meant to improve menstrual cycles, although for me it just wrecked my sleep), and I’ve noticed that I tend to feel wired after looking at it, and that using it for half the day was enough stimulation that I had a great deal of trouble sleeping that night.  So I reckon there’s quite a bit of potential with those little blue bulbs, and they’re better filtered than lightboxes so you don’t get spotting even if you look straight at them.

Light and darkness: an overview

Arguably the biggest factors in sleep pattern regulation are light and darkness.  Humans evolved outdoors, getting plenty of strong daylight during the day and complete darkness at night, and averaging 12 hours of each.  It’s this light/dark signal that keeps the body on a 24 hour schedule: people who are completely blind almost all have sleep disorders, as the natural body clock runs on a 25 hour schedule for some bizarre reason and they don’t have the light/dark signals to keep it at 24 hours.  Now we sleep indoors, we mostly work indoors where the lighting is nowhere near as strong as sunlight, many of us barely get any   sunlight (and those of us with ME, or housebound due to other medical conditions, may not get any), and instead of following the natural pattern of darkness, we are in darkness only for the time we sleep and that may not even be complete darkness, and we will be under artificial light right up until bedtime.  This chart shows the relative light level from various outdoor and indoor conditions.  Even a well-lit office is still only 10% as bright as an overcast sky, and nighttime road lighting is 50 times as bright as a night with a clear full moon.  Our light/dark signals are all mixed up, and this is showing in the  high prevalence today of not only sleep disorders, but medical conditions which are affected by light/dark.

The very basic version is that bright light stimulates serotonin, and a lack of it can cause low serotonin levels and thus depression, as well as daytime sleepiness.  The main antidepressants used today are SSRIs, selective serotonin reuptake inhibitors, and there is a form of depression which is directly caused by low light levels during the winter, SAD (Seasonal Affective Disorder).  Cortisol is another hormone affected by light levels.  Melatonin is the hormone which makes us feel sleepy, along with a host of other roles in the body, and melatonin is produced when we are in darkness, which should average out to 50% of our time over the year but is now nothing of the sort.  The healthy pattern is to start producing melatonin a few hours before going to bed.  By using artificial lighting until right up to bedtime, melatonin production is inhibited, thus ensuring that we are less likely to feel sleepy when we go to bed, and also that we get less melatonin overall than we should.  All the research I’ve read agrees that we need to have melatonin coursing through our bodies for a certain number of hours per day, and that getting insufficient melatonin impacts on various areas of health, such as the immune system, as well as sleep.