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!