Posted tagged ‘Circadian rhythm disorders’

How to shift your bedtime/waking time to earlier

February 12, 2010

When I was using light therapy alone, I found that my 25 hour pattern shifted to 24 hours beautifully but that sooner or later, I would stay up too late and would end up stuck on falling asleep at 4 am or so again.  DSPS is a tough nut to crack.  This was in the days before I found darkness therapy, which has made my sleep/wake pattern rock solid, so here’s how I treated it at the time.

My preferred sleeping tablet when I need one is 20mg temazepam; many people find that 10mg is enough, but I need a higher dose.  While my GP advised me that I should be able to take it for up to a week, I found that taking it for a week straight caused rebound insomnia when I stopped, presumably because the ME/CFIDS makes me over-sensitive to medication.  I find that taking it for three consecutive nights is fine, so I work with that.  It’s entirely possible that I’d be fine with five nights, but I’ve never needed to try.

I would always recommend strongly that you discuss this with your GP.  They should be made aware of your sleeping problems anyway, even if you’re trying to solve them yourself, and sleeping tablets are fairly serious things, even the over-the-counter ones.  Discuss which sleeping tablets will best meet your needs, and if you’ve had a sleep problem for a while you’ve most likely tried several by now anyway.  Do tell them that you will only be using the tablets for a few nights in order to shift your sleep pattern, as otherwise they will be a lot more reluctant to let you have any meds.  I’ve managed to convinced a GP who’d never met me before to let me have four sleeping tablets for this purpose when it was an emergency (missed flight, unexpected night flight), and I doubt that he’d have let me have anything at all if I’d just wandered in to say that I was a bad sleeper and wanted some drugs please.

I’ve always been able to move my sleep back enough over three days using this method, but if I had needed to control a larger shift I would probably have done three days, waited a week, and then repeated the process.  My general lightbox treatment time is 45 minutes, but for this I would sometimes use a longer treatment time to help reinforce the circadian shift.  As far as I can recall, I used an ordinary alarm clock to make sure I got my light therapy at the right time the next morning, but dawn simulation would probably be even better.

Let’s assume that my bedtime is usually 1 am but has shifted to 4 am.

Day 0 – bed at 4 am, wake the next day at 12 pm.
Day 1 – sleeping tablet at 2.30 am for 3 am bedtime, bright lightbox at 11 am.
Day 2 – sleeping tablet at 1.30 am, lightbox at 10 am.
Day 3 – sleeping tablet at 12.30 am, lightbox at 9 am.
Day 4 – no sleeping tablet, lightbox at 9 am.

After that I would relax and use the lightbox whenever I woke up, instead of setting an alarm clock.  This method worked for me every time, including when I had to go on a night flight and deal with a 3 hour time difference to boot.

If you are using darkness therapy, you may not need the sleeping tablets at all.  Just put on the tinted glasses/switch over to orange lighting an hour earlier every evening.  The usual recommendation is to commence darkness therapy three hours before your desired bedtime, though some people find that they get sleepy too early if they do this.  Obviously getting sleepy too early is not a deterrent for DSPS sufferers!

For the above problem, I’d suggest starting the darkness therapy three or four hours before your current bedtime to begin with, and seeing what happened.  It may take a few nights to kick in fully.  Use the bright lightbox when you wake up.  You can wait until you wake up naturally, depending on how effective the darkness therapy is for you, or you can set an alarm so that you make yourself use the lightbox an hour earlier every day.  Since you’re not using sleeping tablets and therefore don’t need to worry about getting the process completed in a hurry, you can try shifting your sleep more slowly, even by 15 min a night.  Keep a diary of what you’re doing so that you don’t lose track.

If you have Non-24 Sleep-Wake Disorder, I’d suggest waiting until your circadian clock has shifted around to your ideal bedtime and waking time before trying anything, then hitting it with light therapy, darkness therapy and/or sleeping tablets to stabilise it there.  The sleeping tablets are a short-term measure, but the light and darkness therapies can be continued full-time and indeed should if you have a circadian rhythm disorder.

If your problem is jet lag or shift work, rather than a misbehaving body clock, you’ll have to experiment to find out what suits you best, and you may only need to use light/darkness therapies occasionally.  Sleeping tablets are best reserved for occasional use, so if you are going to be moving your sleep pattern every week or so, I wouldn’t advise them, and I would certainly suggest that you discuss this with your doctor.  Some companies give their night shift workers yellow safety goggles to wear when they go home in the daytime, so that the light on their journey won’t keep them awake.

If your problem is instead Advanced Sleep Phase Syndrome, then use bright light therapy in the evenings instead to keep you awake for longer.  I have absolutely no idea how darkness therapy would factor in here, but if you’re using it for other purposes (e.g. sounder sleep), I would imagine you would want to be careful not to start it too early in the evening, and remember that darkness therapy alone is unlikely to shift your body clock in the desired fashion.  Light therapy will be the key here.

For any of these problems, dawn simulation alone is unlikely to be enough to shift your body clock, at least in my experience, but may be very helpful in sticking to a good pattern once you have one in place.  I recently went back to dawn simulation, and while I had already stabilised my body clock using light therapy and darkness therapy by now, I think it may be adding a little extra help, and my partner is certainly finding that the dawn simulation makes it much easier to get up in the mornings.

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Bright light therapy: review of the GoLite

February 12, 2010

The GoLite is a nifty little lightbox at only 15 x 15 x 3cm, which makes it extremely portable.  It comes with extra international plugs and a padded carry case, and I have successfully used mine in Israel as well as the UK.  My version is not rechargeable, but the newer ones are, so that if you need to use it somewhere else, you wouldn’t have to scrabble around on the floor to unplug and replug cables.  The case has a clamshell design, so that when it’s closed the lid protects the LED panel, and when it’s open the lid acts as a base.  Unfortunately, the stand is not adjustable and I’ve found that it’s at the wrong angle when it’s placed on a table, so that I have to prop it up on my glasses case.  LEDs are a very directional form of light and you have to position LED lightboxes just right.  While the brightness of traditional fluorescent lightboxes is measured in lux, with 10,000 lux being ideal, the light produced by LEDs is so different that the lux measurement doesn’t apply.  I don’t think I’ve heard yet of an LED lightbox which was not bright enough, but do read reviews if you are looking at different models.

Unlike the lightboxes which came before it, the GoLite doesn’t just use LEDs, it uses blue LEDs. The manufacturers found through research that there’s one particular bandwidth of light that affects the circadian clock, at around 470nm, and luckily blue LEDs naturally peak in exactly that bandwidth.  (Despite what the manufacturers claim, all blue LEDs do this, so any lightbox with blue LEDs should do the same job.)  Traditional fluorescent lightboxes do contain some light in that bandwidth, but they don’t have very much of it.  By isolating the correct bandwidth, the idea is that you can get away with a smaller lightbox and a shorter treatment time, thus hugely increasing how effective it is.  My experience and all the reviews I’ve read of blue lightboxes appear to bear this theory out.  The manufacturers recommend a treatment time of 15-45 minutes, which for bright lightboxes is excellent, and even with stubbon sleep disorders I have always found 35-45 minutes to be sufficient.  The snag is that not everyone likes blue light, but most people are fine with it and it’s a pretty soothing light as such things go.  I have difficulty tolerating bright light and I’m absolutely fine using the light on full intensity.  The build quality appears to be good and the only problem I’ve had in five years of near-daily use is that one of the 66 LEDs now only lights up intermittently, which does not affect the efficacy or visual comfort at all.

Apart from the inability to adjust the stand and the high price, my only niggle with the GoLite that I own is that the settings are a nuisance to understand and the instruction manual wasn’t much help.  It does have various features, including a clock, treatment timer, variable light intensity, and the ability to save three different programmes, but you may need to ring up your seller or the manufacturer in order to learn how to do this.  It’s not intuitive to set, involving strange combinations of holding down several buttons at once, and you’re unlikely to remember how to do it.  After five years of use, I’ve sorted out my preferred treatment time and light intensity so that I just need to turn it on and hit “light” in order to get my treatment running, but I have no idea how to change the programme settings or even how to change the time when the clocks go back.  Thankfully I only use the one programme and don’t use it as my clock (it lives in a bedside drawer when not in use), so this doesn’t particularly matter.  I did try using Programme B for a shorter treatment time with lower light intensity for when I had a headache, but eventually I stopped bothering.  If I have a migraine, I skip the lightbox for that day, and if it’s only a mild headache, the light doesn’t seem to do me any harm.

The GoLite was my first big step in improving my sleep.  Before using it, my daily pattern was 25 hours, so that I would fall asleep an hour later every day.  I started using the GoLite when I woke up, and the pattern immediately stabilised at 24 hours.  With judicious occasional use of sleeping tablets, I could even move my bedtime and waking time back when they had crept too far forward, although I still tended towards late hours and had to accept that while the Non-24 Sleep-Wake Disorder was now firmly under control, the Delayed Sleep Phase Syndrome was only partially managed.  (Darkness therapy is what finally solved the latter.)  After some experimentation, I have settled on a 45 minute treatment time, although now that I am using darkness therapy as well I may be able to get away with less.  I found after a few years that even if I skipped my treatment for the odd day here and there, my sleep pattern remained stabilised at 24 hours, so it seems that to some degree my circadian clock has been retrained.

I bought my GoLite in 2005, back when it was the only LED lightbox on the market and pretty new at that.  The version I bought was the P1 (the link takes you to the place I bought it from, which I highly recommend).  As you can see, it’s still for sale at quite a good price now, although some people may prefer to pay more for the newer, fancier versions.

Back then, the GoLite was made by an American company called Apollo Health who made a variety of fluorescent lightboxes as well and had done quite a lot of research into light therapy.  I loved their website.  It had some of the best information about bright light therapy for various conditions that I’d ever seen, and devoted plenty of space to sleep disorders, where most lightbox manufacturers just talk about SAD.  It even had a free test you could take to find out whether you had a circadian rhythm disorder, rather like the Morningness-Eveningness Questionnaire.  When I rang the company, there was an extraordinarily knowledgable chap I could speak to about exactly how I should treat my sleep disorders using light therapy.  Apollo Health has since been taken over by Philips, which means that you have a household name, you can speak to customer services in your own country, and it’s doubtless doing great things to get the product out there, but that wonderful resource of the Apollo Health website has been lost.

The new GoLite

Philips have redesigned the GoLite so that it now looks rather different.  I haven’t tried it out yet, but I’ve spoken about it in some depth to the National Light Hire Company.  It does look snazzier, but frankly I’m not that interested in its decorative value and it’s certainly not something I’d be willing to pay more money for.

The new GoLite BLU (no, Philips, misspelling words does not make your product more attractive to me) still lacks an adjustable stand, but it does feature a built-in battery, so that it is rechargeable.  I’ve always hated having to mess around with unplugging cables whenever I wanted to move my lightbox to the other room, so this would have been a very useful feature for me, and it would have made it easier to take over to my partner’s flat in the days before he moved in.  I’ve read that it has a much wider treatment angle than the older model, though I’ve not been able to confirm this.  When I talked to the National Light Hire Company, we discussed how it compared to the Lumie Zip, another popular LED lightbox, and they said that the new GoLite has a lot more features than the Zip and is generally more modern and high-tech.  They did not know whether it was easier to use, but judging from the user manual it’s still awkward.  It features a touchscreen, which I suspect may make it even more awkward when it comes to holding down two buttons at once, although at least the display looks nice and clear, in a blue that matches the bright light panel.  Abandoning the clamshell design of the older GoLite means that you no longer  have a back that can flip over to cover the screen. From having knocked mine onto the floor countless times over the years, I think the GoLite is sturdy enough that it doesn’t matter, and they do provide a nice slimline carry case.

The GoLite continues to be known as one of the highest-quality lightboxes around, and its small size and relatively short treatment time give it a big advantage over traditional fluorescent lightboxes.  It is no longer the only LED lightbox on the market, however.  Apart from the  popular Zadro (not available in the UK), all other LED lightboxes provide white light which peaks in the blue spectrum.  Blue provides a gentler light and possibly (but not necessarily) a slightly shorter treatment time, while white is likely to be more acceptable to anyone who is picky about their light colour, for instance if they need to make colour judgements.  Whether you prefer to pay more for the additional features and reliable brand name, or save money to get a more basic LED lightbox, is up to you.  If I were starting over with light therapy now, I think I’d buy a cheaper lightbox but make sure that it was from somewhere with a good returns policy in case of faults.

Darkness therapy

January 26, 2010

The idea behind this is that humans do best when they have melatonin being produced for half the time (averaged out over a year, it won’t be 12 hours all the time unless you’re living on the equator), and that it’s useful both for aiding sleep and for other things such as fertility and cancer risk.  I’m a little warier of claims that a yellow light bulb will fight cancer/get you pregnant than I am of the claims that it will improve sleep, so I’d treat that side of things as rather more speculative, but there does seem to be a fair amount of research backing it all up, if indirectly.  While darkness therapy itself may be fairly new, the various roles of melatonin have been studied a great deal by now.    There have been studies using 12 hours of complete darkness to treat bipolar disorder, but this is difficult to implement and is generally thought not to be necessary, though I’ve read a website by one guy who feels that it is essential and discusses washing up in the dark!  So while there appears to be a great deal of research on melatonin and sleep in general, for instance how shift work affects breast cancer risk, or on populations who do not have artificial lighting (and have many other major difference from industrialised countries), there is as yet little where researchers have directly studied darkness therapy by taking a group of people and changing nothing except the amount of darkness they get at night.  Hopefully this will be remedied before too long, although since there’s nothing in it for pharmaceutical companies, it may take a while.  All the research that I do know of can be found at LowBlueLights.com.

Since it’s blue light which affects circadian rhythms and tells the body that it should be awake and not producing melatonin, you can practise darkness therapy by simply omitting or filtering out blue light for several hours before you go to bed and while you are in bed.  There are a few ways of doing this, but the crucial thing is that once you have begun the darkness therapy in the evening, you do not get any white or blue light until the next morning, not even the tiniest bit.

Coloured light bulbs. For general use while awake, I prefer yellow-coated incandescent bulbs.  If you’re in the UK, they’re just sold as yellow bulbs.  If you’re in the US, they’re more likely to be called bug lights.  The bulb should be painted completely yellow, with a solid coating rather than a translucent one, and will produce an amber light which I find pleasant but which my partner, who generally dislikes coloured light, can’t stand. You can also get amber, red, or pink-coated bulbs, which you may prefer.  I’m not entirely sure whether the pink ones will filter out all blue light when used in an ordinary lamp, as I’ve only ever tried a 15W one inside a salt lamp, where the thick salt already filters out most of the blue.

Unless you live alone or are only planning to use these lights while alone (e.g. while breastfeeding or if you need to get up in the night because you can’t sleep), this is a potential snag.  As the coating is substantial, it will reduce the overall light output so that a 60W yellow bulb may be only as bright as a 40W white bulb, or even dimmer than that. You can buy fluorescent versions of these yellow-painted lights as well.  I haven’t tried them yet as I respond so badly to all fluorescent light, but I’m curious about how the yellow coating changes the level of visual comfort by filtering out certain bandwidths.  I tried buying an LED bulb that was sold to me as yellow, but it turned out to be a really nasty street-light orange; same goes for the two types of LED tea lights that I’ve tried.  I’ve been told by several lighting merchants that oranges and yellows are problematic for LEDs, it’s hard to get a pleasant colour.  I haven’t tried yellow halogen bulbs, but from the photos the yellow coating doesn’t look  strong enough to block all blue light.

For use when I’m going to the toilet at night, I bought a couple of red bike lights.  Since I’m an evening bather, showering was a problem.  I originally tried a red bike light, but while I can cope relatively well in near-darkness, it just wasn’t safe.  After puzzling over this for some time, I put a couple of lamps with 60W yellow bulbs on the hall, so that when the bathroom door is open, there’s a decent amount of light.

Even with coloured light bulbs, it’s best to keep the lighting in the evening fairly low.  At one point I had a 60w yellow bulb in a desk light by the bed for reading by, and a 25w bulb hidden behind a vase in the corner on my partner’s side of the bed for ambient background lighting.  Once I got the orange glasses, I eventually stopped using those, though I did acquire a salt lamp for ambient lighting which provides a nice orange glow.   (As far as I can tell,  the salt lamp filters out most blue light but not all, so you may need to get a coloured bulb for it if you’re going to be using it without tinted glasses on.)  If you do get tinted glasses, I’d recommend keeping on one lamp with a yellow bulb by the bed, for the occasions when you need a bit of light during the  night and don’t want to put your  glasses on.  There are various forms of gentle ambient lighting which are naturally low in blue light, such as candles or fairy lights, and for some people these will be an acceptable compromise.  If you go for fairy lights and you’re not going to be using tinted glasses, go for rice lights, which are a warm white, instead of LED lights, which are a cold light containing a lot of blue.  Unfortunately, I’ve found that even the small amount of light from fairy lights can be enough to halt melatonin production and keep me awake for hours if I don’t have my orange glasses on.  I may try “golden” LED fairy lights some time, but since all of the LEDs I’ve bought as yellow turned out to be a nasty orange, at the moment I’m using the salt lamp for my one yellow lamp.

Monitor filters. Computers and television screens emit an awful lot of blue light, and using them in the evening can really mess up your sleep all on its own.  Low Blue Lights and its friends sell expensive amber filters, but I simply got some samples of amber gels from a theatrical lighting company and cut them to size.  They stick on fairly well by static, unless you have the computer screen tilted quite far forward, and are easy to take off for daytime use.  I have a 17″ widescreen laptop and there are several inches to spare, so these would probably do you for up to 19″ or 20″ widescreen.  They’re a bit of a nuisance, they won’t work for larger monitors, and again my partner doesn’t like looking at them (some people just don’t get on with coloured light), but they’re cheap.  Brown filters should theoretically do the same job with minimal colour distortion if you can’t stand orange, though they will need to be fairly dark.

If you’re looking at a monitor through an amber filter or glasses, colours will be quite strongly affected.  The general effect is golden yellow more than orange, oddly enough.  Whites will be yellow, blues will be greens, everything will be a bit different.  This may annoy you, and it may restrict your activities.  I can’t do any quilting that requires me to select colours, and it’s not the time to go internet shopping for clothes.  This isn’t entirely a bad thing, as it forces me to wind down in the evenings and look at those hours during darkness therapy as relaxation time.

Tinted glasses.  There are two ways of doing this.  You can buy ready-made tinted glasses which will block all blue light, for instance from the range at Optima Low Vision, or you can get prescription glasses made up with a tint that will block blue light.  If you want to try standard sunglasses in brown, orange, yellow or red, check with an optician to find out whether they block 100% of blue light, as apparently most of them don’t.  You also want these glasses to provide good coverage, as opposed to some of the tiny lenses you can get these days.

If you’re going for anything expensive, try out darkness therapy with coloured bulbs and optionally monitor filters first to see whether you get on with it and whether it helps.  Since I can’t see without glasses, I decided to try some fitover glasses in amber which had the advantage of very good coverage.

Unfortunately I found them horribly uncomfortable, and they looked terrifying on me, being huge and so dark (much darker than the image shows) that my eyes were utterly obscured, along with half my face.  My partner and I didn’t want our evenings together spoilt by this, so I gave up on the fitover school of thought and had some prescription glasses made up instead.

On my optometrist’s advice, they were tinted with Wratten Tint 21, which is a pleasant orange.  Optical Express (who do some rather nice cheap frames) don’t do that tint as standard, but they could get that orange in 50% light transmission, which was more than enough to block 100% of blue light but still not so dark that my eyes were obscured to someone looking at me.  They called it 500 Orange 50%, and it cost the same as an ordinary tint. (Remember that brown is just orange with black added, so while they will look more conventional and may distort colours less, brown-tinted glasses will need to be darker.)  The glasses are rather fetching, if I say so myself, and I’ve had no complaints that they make me odd to be around.

I still keep the ambient lighting low when possible, as there will be a bit of light creeping in around the edges, and sometimes I put on the salt lamp so that the light is a soft orange.  However, I’ve spent enough time wearing these glasses with ordinary indoor lighting to confirm that they work beautifully in any conditions, and you don’t need to worry too much about what your light bulbs are up to.

I generally put on the glasses at about 9.30 for a bedtime of midnight, and have been using them for four months.  I’m getting sleepy earlier in the evening, sometimes I even fall asleep at 11ish, and I’m sleeping more solidly.  I’d estimate the effect of the darkness therapy to be similar to that of taking a sleeping tablet in terms of getting a good night’s sleep, but without the potential side effects or grogginess the next day.  I find the glasses very relaxing to wear.  If my partner comes home late in the evening, in the past I’d be so thoroughly woken up that I couldn’t get back to sleep for hours.  Now he’s lucky to get a coherent “hello darling” out of me, and I go straight back to sleep.  I haven’t had an episode of not being able to sleep until unholy o’clock in the morning, or waking up at night and not being able to get back to sleep for well over an hour, since I started using the glasses. There have been a few nights where I’ve forced myself to stay up until 2, yawning all the time, but where in the past (using bright light therapy alone) I would have messed up my sleep cycle by doing that and would be unable to sleep before 2 (or worse) for the nights afterwards, now (using bright light therapy, dawn simulation and darkness therapy) my sleep pattern snaps right back into place.  The only exception to this is the one night where I made the mistake of having the fairy lights on for half an hour around midnight when my orange glasses were off, as I’d hoped that they were yellowy and dim enough not to disrupt melatonin production.  The ensuing insomnia made me realise just how dreadful my sleep was in the old days, and how enormously it’s improved since then.

What colour light should a lightbox produce? White, blue, full-spectrum?

January 26, 2010

There’s rather a kerfuffle going on amongst lightbox manufacturers as to what is the correct colour for bright light therapy.  Older models of lightboxes all used white fluorescent light, and I think that what is going on is mainly about the longer-established manufacturers trying to hang onto the market, while the new ones are trying to persuade customers that their exciting new product is superior.  So on one side you have old-fashioned white lightbox manufacturers baying that blue light will ruin your eyes, and on the other you have blue lightbox manufacturers claiming that blue light is all that matters.

From all the research I’ve read, it does seem that blue light is the most effective bandwidth.  Blue light is, of course, contained in white light, and even the brightest lightbox will not be as bright as outdoor sunlight.  If thirty minutes in front of a little lightbox was enough to wreck everyone’s vision, we’d all be blind from the sun by now, even with modern indoor living.  Psycheducation.org has written an excellent article on the purported dangers of blue light, concluding that unless you are at high risk of macular degeneration, you don’t need to worry, and to be sensible and not stare directly at your lightbox.

This spectrograph was produced by Apollo Health, the former manufacturers of the first blue lightbox, the GoLite, so it’s not from an unbiased source.  However, all the research I’ve read agrees that 470nm or thereabouts is the most effective bandwidth for affecting the circadian clock, and I’ve seen several spectrographs of fluorescent light (which is the  “standard full-spectrum” in this graph) that look the same.  Fluorescent light is spiky, which is apparently why it’s so harsh on the eyes, and even the full-spectrum versions don’t peak at 470nm.  Presumably this is why fluorescent lightboxes are a great deal larger than LED lightboxes and require longer treatment times.

Something interesting about LEDs is that the blue ones all seem to peak around 470nm naturally (warning: the page has lots of images and takes a long time to load).  This is why I suspect that using a standard blue LED bulb may not be as strong as a fancy lightbox, but it’s the right type of light and if used for longer, may have the same effect.  Typical white LEDs contain a broader bandwidth of light overall, but they turn out to peak around 470nm too (also a long page).  Here’s a typical example of a white LED bulb.

Some lightbox manufacturers claim that their LEDs are “blue-enriched white”, but frankly I think that they’re perfectly ordinary LEDs, the manufacturers are just cashing in on the fact that they happen to peak in the blue bandwidth.  (The advertising shenanigans of light therapy manufacturers can drive you demented at times.)

This means that white LEDs produce a cold light that most people don’t particularly like for domestic lighting, but it makes them ideal for bright lightboxes.  I’ve concluded that while blue light is the most effective, white LEDs are so close behind that you may as well choose your lightbox based on your personal preferences.  Some people find the blue light to be softer and less disruptive, other people find that they need white light so that they can look at colours properly (I once made the mistake of trying to do some embroidery with my GoLite on, and had to unpick it all afterwards as I’d picked up the wrong coloured threads), and a few people, such as my partner, just can’t get on with coloured light.  Choose according to your visual comfort and the other factors involved in choosing a lightbox, such as price, overall product quality and the various features that a lightbox can have.

If you prefer fluorescent lightboxes, there is the question of whether to go for normal or full-spectrum.  As far as I can tell, it doesn’t make any difference therapeutically, so go for whichever light you find to be most comfortable for your eyes, if you can even tell the difference.

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Images courtesy of the LED Museum.

Bright light therapy

January 26, 2010

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.

Finding your best sleep pattern and napping

January 26, 2010

It’s useful to know that a sleep cycle is 90 minutes long, and it’s best to be sleeping in multiples of 90 minutes, as this means that you will be waking up at the right point in your sleep cycle, rather than feeling horribly groggy because you were woken out of deep sleep and going straight back to sleep. Some people do best on a siesta pattern, which is commonly practised in hotter countries.  I fall into this pattern occasionally myself, but I find it too difficult to keep up.  I’ve spent enough years telling people not to call me in the mornings as I may not be awake, I know how disruptive it is to sleep during the working day.  In addition, I want to be going to bed and getting up at the same time as my partner, and I find it easier to control my sleep if I’m having my night’s sleep all in one go.  Sleeping in the day is more likely to cause my sleep cycle to end up askew, for instance getting stuck at falling asleep at 4 am.  It may work for you, though.  Try 1.5 or 3 hours for a siesta.

The 90 minute cycle also affects when you will feel sleepy in the evening.  The Myhill article above talks about “sleep gates”, which usually occur at intervals of 3 hours, and while she advocates an incredibly early bedtime, it’s still useful information no matter what time you go to bed.  I often get sleepy around 9 pm or 6pm, and it’s useful to know that I should make a special effort to keep awake and it will pass.  It’s also made me aware that missing my usual bedtime is really not a good idea, as I then may end up lying awake for hours.

I do nap occasionally when I really need it.  The sleep specialist advised me not to nap for more than one hour, as after that you get into deep sleep and it will disrupt your night’s sleep.  This advice was excellent.  I don’t fall asleep immediately, so I set a timer for one hour and ten minutes.  I also make sure that I nap with the curtains open and the light coming into the room.  No one suggested this, but I reckon it will help my circadian clock realise that this is not nighttime, and I do find napping easier now that I’m following these two rules.  If for some reason my sleep has been totally messed up and I need to catch up on several hours, I may draw the curtains, but thankfully this is rare.

Over the years, I’d heard a number of suggestions about how I could try to change my sleep patterns.  Some have been from books or doctors, some have been from well-meaning friends who knew nothing about sleep disorders.  None of them worked, and most of them sent my sleep pattern completely haywire.  Here are the techniques I don’t recommend for ME or circadian rhythm disorders.  If you have DSPS or Non-24 Sleep-Wake Cycle, you’ll most likely have tried some of them already.

Don’t bother with:

  • Going to bed earlier (unless it’s for a short period where sleeping tablets are used, probably in conjunction with light therapy).
  • Forcing yourself to get up earlier.
  • Staying up all night in the hope that you’ll fall asleep at a more reasonable hour the next night.
  • Going to bed three hours later every night until a suitable bedtime is reached (called chronotherapy).

No doubt these may work for some people who are experiencing a mild one-off problem with sleep, but for entrenched circadian rhythm disorders they are not only pointless, in my experience, but can exacerbate the original problem while causing very unpleasant sleep deprivation.  You are of course welcome to try going to bed or getting up earlier to see if it works, but I don’t think there’s a single person out there with DSPS who hasn’t tried this over and over again.  If that was all we needed to do to cure DSPS, the sleep disorder wouldn’t exist!

Get a diagnosis

January 26, 2010

Work out what’s wrong with your sleep, and if necessary, see a doctor or even a sleep clinic.  Some sleep problems such as sleep apnoea are actually quite dangerous and warrant early investigation.  Note that in the UK at least, sleep clinic waiting lists are long, and if you’re paying for your healthcare then a sleep study is expensive, but it’s generally worth telling your GP what is going on at the very least.  Keeping a sleep diary for a while (a week, a month) can be very useful.  You will want to note down when you sleep, when you doze, when you get up, when you take any meds or treatments that can affect sleep or alertness, and optionally when you eat and get exercise.  If you have sleeping partners, ask what they’ve noticed (e.g. stopping breathing during sleep, waking up with amnesia).  I’m generally going to be talking about circadian rhythm disorders, such as Delayed Sleep Phase Syndrome (when you’re an extreme night owl, e.g. you can’t get to sleep earlier than 4 am no matter how hard you try) and Non-24 Sleep Wake Disorder (when your body clock is running on a 25 hour or 26 hour schedule, so that you will fall asleep an hour or so later every day, which is like living with permanent jet lag), as well as general insomnia and poor sleep quality.  If you have ME, chances are that your sleep will be poor no matter what you do, but it may be possible to improve it to quite an extent.