Randomized study procedures. A 12-minute bright light dose was administered transcranially via the ear canals daily after awakening. The intensity of the transcranial bright light (TBL) was 1, 4 and 9 lumens in treatment groups 1, 2, and 3, respectively. Depressive symptoms were evaluated using the SIGH-SAD, HAMA, and BDI measurements. Cognitive performance was measured using the Trail-Making Test (TMT) part A and B.