A reader asks:

 I have been treated for major depression and bipolar disorder for several years, with different medications, but with no significant relief! Recently, I purchased a light box, but after six days I have had no positive relief. Does light therapy have a different time frame for positive results on different people and different clinical depressions? Will it take longer for me to see an improvement in my mood because of my specific condition? Should I increase my duration of treatment from 30 to 45 or 60 minutes in the early a.m.?


Don’t Self-Treat

First of all, we do not recommend self-treatment of major depression or bipolar disorder. There are too many interacting factors that need to be sorted out by a clinician–and although it is possible that you will experience improvement without such guidance and monitoring, if you don’t, you are not in the best position to decide next steps on your own. We can generalize about some factors that might be operating in your situation, however. Patients with bipolar disorder should use light therapy only after establishing a steady dose of a mood-stabilizing drug (examples: lithium, Depakote). Otherwise, they are vulnerable to sudden switching between extreme mood states, sometimes with rapid cycling, which can be extremely distressing. Some patients with bipolar disorder have responded preferentially to light therapy at midday rather than early morning, which is a milder treatment strategy-one which most patients with SAD do not require.

Personal Variations in Treatment

Research suggests that patients with non-seasonal depression respond more gradually to light therapy than do patients with SAD, and the clear onset of positive effect may not be apparent for several weeks. In one study of non-seasonal patients with chronic, major depression, light duration was standardized at 60 minutes at 10,000 lux, while in another study of non-seasonal bipolar disorder, very short exposures (15 minutes) appeared optimal. Some patients with non-seasonal depression respond adequately to a combination of light therapy and antidepressant drugs, while either one alone is insufficient. We hope you see why clinical management may be very important for you.