last updated 2/19/2024
First, consider the really simple version of light therapy: using a “dawn simulator“. Treatment is done by the time you wake up. No side effects. No risks. Cheap. Easy to use.
But when they say “light therapy”, most people are referring to sitting in front of a high intensity light box for 30 minutes every morning. Let’s look at that version more closely.
Does this really work? (you bet it does)
Not just for “seasonal depression”; for non-seasonal depression also, as in the results of this key study.
Got it? Light therapy with a light box was better than a common antidepressant pill, fluoxetine, without the sexual side effects (well, basically the same such effects as placebo; it’s never zero in these questionnaires…).
Two risks to consider
Inducing manic symptoms
As you can see, light therapy is an antidepressant. Antidepressants, including light therapy, can cause manic symptoms — and also “mixed states” where manic and depression symptoms combine. Mixed states can happen to people who are in the middle or at the bipolar end of the mood spectrum. (The MoodCheck questionnaire can help you see where you are on that spectrum.)
Eye risk
Here’s a list of people who should not use a light box. If you have any doubt, ask your doc’ or nurse practitioner.
- You have macular degeneration, or a family history of macular degeneration
- You have porphyria, lupus, actinic dermatitis (seriously sun-damaged skin), or solar urticaria (sun makes your skin hurt)
- You take a medication that sensitizes you to light (some antipsychotics called phenothiazines, tricyclic antidepressants, St John’s Wort, tetracycline, antimalarials, diuretics like hydrochlorathiazide, sulfa antibiotics, and some medications for rheumatoid arthritis, cardiac arrhythmias, and psoriasis.
- And if you have diabetes and eye problems from that — well, you get the drift. This is high intensity light. You have to be careful with it.
How to do it?
Ideally you can borrow a light box for two weeks. That’s usually enough time to decide whether it’s actually helping you. If it has, then you’ll need to arrange a way to continue. A good quality light box costs about $140. Here’s an example.
Notice that it’s:
- large: so you can move your head and still be near it
- higher than your eyeball: best if the light comes from above your eyes
What can I do while I sit there?
You’re gonna be stuck here for 20-30 minutes. You can have breakfast, read a newspaper (oh, wait, no one reads the newspaper anymore; okay, fine, read the news on your phone or tablet). Write a letter to your mother on your computer.
The point is, be prepared to sit in one place. You don’t look at the light, you are simply in it’s field. So you can do something entertaining (or better yet, useful).
First thing in the morning?
In theory you should start your 30 minutes based on your biological clock. But you have a life! So start the 30 minutes where you can fit it in, early in your morning. (If your “morning” starts at 10 am or later, you should probably watch my video about regular bedtimes and rise times and moving them earlier, closer to the sun — the second half of the video).
Which box should I buy?
That’s easy: you want to have 10,000 units of light reaching your eyeball. What? Okay, let’s make it simple. At minimum the box you buy should say “10,000 lux”. But little ones, you’ll have to be really close and put it up on a pile of books to get it above your eyeball. Bigger ones come on a stand and you can be about a foot-and-a-half (half a meter) away.
If you’ve used a little one and it works, well then it doesn’t matter: it worked! If you tried a box for 2 weeks and it didn’t work, perhaps it was too small. Or you were looking away too much. That’s the downside of small.
More?
Wow, I just looked at my old website page on light therapy. It goes into much more detail on all these questions. So, have a look if you want more.