The Lowly Dawn Simulator

December 8, 2016

Is it time to think outside the light box for treatment of seasonal depression?

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“Light therapy” makes everyone think of light box therapy. You know, sitting in one place for 30 minutes when one should be starting one’s day. But another light therapy is easier to use regularly, is less expensive, and has no recognized capacity to cause harm.

Enter the lowly dawn simulator. You’ve probably heard of it, and a few readers are actually using one every day this winter. It gradually raises the intensity of a simple bedside light (not a light box) over 30 to 60 minutes in the morning, “simulating dawn.” These devices have produced better outcomes than plausible placebo devices in seasonal depression1 and nearly as good outcomes as light box therapy,2 indeed better than a light box in one randomized comparison trial.3

A dawn simulator is much easier to use regularly than a light box. The gradually increasing light reaches the retina through your translucent eyelids. By the time you wake up, the treatment is complete. Just get up and start your day. No 30-minute halt to sit in front of a bright light.

To paraphrase a commentary on bupropion for unipolar depression4: “Why aren’t dawn simulators the most frequently prescribed antidepressant for bipolar depression?” First, there are no randomized trials of dawn simulators in bipolar depression. And no such studies are listed at, either (ie, none under way or recruiting).

On the other hand, remember that conventional antidepressants have very little direct evidence for efficacy in bipolar depression either, at least in bipolar I.5 As the British Association for Psychopharmacology summarized in their 2016 treatment guidelines, antidepressants are used in bipolar depression by extrapolation from their data in unipolar depression.6 Thus, just as with antidepressants, we are at liberty to extrapolate the efficacy of dawn simulators in bipolar depression. And-here’s the point-unlike antidepressants, dawn simulators do not carry the risk of inducing hypomania, mania, rapid cycling, mixed states, or suicidality.

Why underutilized?

Why not then just start with a dawn simulator for your next patient with bipolar depression? Answer: unlike pills (but like light boxes), dawn simulators require a lot of explaining. First, one must help a patient understand that turning on a standard bedside light gradually can have an antidepressant effect, while the very same light, turned on suddenly, would not. (The latter does not entrain circadian rhythm as well.7)

My website for patients and families includes plain-English but detailed information on light therapy generally and dawn simulators in particular. These pages allow patients to digest rather complex choices at their own pace, re-reading where necessary and exploring the references where inclined.

Second, one must explain how to use the device, which for many of them is not simple. Even my favorite-because of its $20 price-takes some hand waving, and some patients won’t figure out the programming. Then comes perhaps the most limiting factor of all: you can’t write a prescription for a dawn simulator. (Well, of course you could, but if you’ve ever fought with an insurance company to get them to pay for a light box, you can imagine the effort it would take to push through a dawn simulator.)

To help patients around this barrier, our office purchased a couple of the $20 simulators and we sell them at our cost to patients at our front desk (using the money to buy more as we run low). If that’s impractical for you, at least buy one and keep it in your office as an example. (Maybe two: set the other one up in your bedroom to try out! It probably won’t make it to your office after that.)

Here’s a twist, however. I’ve always thought that once patients set up a dawn simulator properly, they would prefer it to light box therapy. Interestingly, a recent study from Russia subjected dawn simulators and light boxes to a direct, randomized comparison in the treatment of seasonal depression.8 Dawn simulators were preferred over light boxes, as I had expected-except among those who perceived the light box to be more effective.

Are there


risks? One reporter for NBC News described being pounced upon by her Pomeranian one morning while trying a dawn simulator.

Actually, both treatments were equally effective, leading to 42% and 44% reductions in depression scale scores for dawn simulators and light boxes, respectively. But the preference factor illustrates that understanding patients’ expectations for light therapy is important: if they think a dawn simulator is a poor substitute for the “real thing” (a bright light box), that could affect the outcome of their light therapy.

Which one?

The few quality randomized trials of dawn simulators have not established a particular design to recommend (thus, my choice based on cost). Recently developed smartphone apps for Android and Apple have not been tested clinically. Their instant availability, portability, and price (most are free) are attractive. Caution: some use the phone face, some the flash. A research trial to establish efficacy of each is needed. Patients who do not respond to a trial of a phone app should not conclude that a dawn simulator using a bedside lamp would not be effective.

Are there any risks? One reporter for NBC News described being pounced upon by her Pomeranian one morning while trying a dawn simulator. The dog’s circadian rhythm had responded to the gradual light, but she had not. At least she exhibited a slight bit of humor about this . . . And one must inquire about bed partners who might be on a later schedule, to avoid triggering conflicts there. But otherwise, to my knowledge, the dawn simulator has not been associated with any adverse effects. Besides, even if it didn’t work for mood, wouldn’t you rather wake up in a room full of light than in the dark to a jangling alarm clock? Will you try one, so as to be able to advise your patients about them?


Dr. Phelps is Director of the Mood Disorders Program at Samaritan Mental Health in Corvallis, Ore. He is the Bipolar Disorder Section Editor for Psychiatric Times. Dr. Phelps stopped accepting honoraria from pharmaceutical companies in 2008 but receives honoraria from McGraw-Hill and W.W. Norton & Co. for his books on bipolar disorders.


1. Golden RN, Gaynes BN, Ekstrom RD, et al. The efficacy of light therapy in the treatment of mood disorders: a review and meta-analysis of the evidence. Am J Psychiatry. 2005;162:656-662.

2. Terman M, Terman JS. Controlled trial of naturalistic dawn simulation and negative air ionization for seasonal affective disorder. Am J Psychiatry. 2006;163:2126-2133.

3. Avery DH, Eder DN, Bolte MA, et al. Dawn simulation and bright light in the treatment of SAD: a controlled study. Biol Psychiatry. 2001;50:205-216.

4. Zimmerman M, Posternak MA, Attiullah N, et al. Why isn’t bupropion the most frequently prescribed antidepressant?J Clin Psychiatry. 2005;66:603-610.

5. Pacchiarotti I, Bond DJ, Baldessarini RJ, et al. The International Society for Bipolar Disorders (ISBD) Task Force report on antidepressant use in bipolar disorders. Am J Psychiatry. 2013;170:1249-1262.

6. Goodwin GM, Haddad PM, Ferrier IN, et al. Evidence-based guidelines for treating bipolar disorder: revised third edition recommendations from the British Association for Psychopharmacology. J Psychopharmacol. 2016;30:495-553.

7. Norden MJ, Avery DH. A controlled study of dawn simulation in subsyndromal winter depression. Acta Psychiatr Scand. 1993;88:67-71.

8. Danilenko KV, Ivanova IA. Dawn simulation vs. bright light in seasonal affective disorder: treatment effects and subjective preference. J Affect Disord. 2015;180:87-89.