A reader asks:

 I have been using a light box, the one you recommend, for about a month. I use it for a half hour, generally between 7:30-8:00 AM during the week and at 8:30-9:00 AM on weekends. I was not depressed when I started using it. My therapist and pharmacologist suggest that I use it as a buffer from depression. How long do you suggest I use the light box? Can I stop during the spring and continue again in the fall or winter? I have a bipolar illness, and have been stabilized for 10-15 years. However, I am very light sensitive. I feel uncomfortable in dark places, and much better in the light. I am somewhat a fanatic about that.


No one has ever demonstrated that light therapy buffers against depression in non-depressed people, although that is conceivable. Not to throw cold water on your doctors’ strategy, but it is also possible they think using a light box would help maintain your good mood through its placebo effect. However, if difficulty awakening has been one of your problems even when you’re feeling well, the light box could be useful. And the light box can be used in conjunction with meds to enhance overall response–that is, to reduce the residual symptoms that meds fail to treat. If your historic problem is winter-seasonal, it makes sense to discontinue lights in early May, but if your historic problem is non-seasonal, whatever benefits you are finding with light could last year-round. Obvious strategy: if you begin to slump when you discontinue the lights, resume them!