Effect of bright light therapy for depression

Abstract

Depression is a common mental disease, which affects the quality of life. It can be divided into seasonal affective disorder and non-seasonal depression. It has been proved that light therapy has effective therapeutic effect on seasonal affective disorder, while the effect of light therapy on nonseasonal depression need further verification. In this paper, we studied on the effect of bright light therapy on non-seasonal depression. The condition of bright light therapies were: evening treatment conducted from 18:00 to 19:30 and morning treatment conducted from 8:00 to 9:30. The conclusions were: bright light therapy conducted in evening and morning could lift spirits, lead to the decline of heart rate and blood pressure. Also, for people with non-seasonal depression, evening bright light therapy was more effective than in the morning (p=0.004<0.05). Treatment for controlled trial got similar effect of improvement, yet showed no significant difference between evening and morning treatment (p>0.05). This paper verified the effect of improvement of bright light therapy for people with and without non-seasonal depression. Furthermore, we found an optimum condition of bright light therapy for non-seasonal depression treatment, conducted from 18:00 to 19:30 with its CCT of 4400K.