Seasonal Affective Disorder (SAD)
The first use for Bright Light Therapy was for treating SAD. Extensive research has been done substantiating the effects many of us have seen in our work with people with SAD. In fact, some studies have shown LT to be more effective than SSRI anti-depressants for SAD. The summary for one of these studies can be found at: nih.gov
This over twenty year period of studying Bright Light Therapy has also been important in determining that this type of light exposure is safe. Although early equipment exposed people to UV rays, currently available lights do not expose users to this problem.
A long term followup study in Scandinavia of people with SAD who were on medication prior to being introduced to LT found that 94% had stopped the medication and used only LT for treating their SAD. That study is summarized at: ncbi.nlm.nih.gov
Although most people with SAD benefit from using the light when they first get up in the morning, some find the light helpful but only when used at other times of the day. Greater benefit is also often possible from multiple sessions of bright light exposure each day. If your schedule of waking varies from day to day a customized plan for using the light will likely be best for you.