PMC

Average hourly light exposure for the 7-day period prior to the baseline measurements (black line), and during the 7-day period of morning light therapy (red line). Asterisks indicate periods of time where the average hourly light exposure was significantly greater (p < 0.05) during the week of morning light therapy. Error bars represent ± the standard error of the mean hourly light exposure. The extra light exposure due to the light therapy was accounted for in this analysis by adding an additional 500 lux of light exposure to the recorded ambient light exposure for each minute of the diary-reported 30-minute period that each participant wore the light therapy glasses on each day of the light therapy week (the mean reported time that the light therapy glasses were worn was 07:08 am ± 00:51 min; range: 05:30 to 11:01am).

Flow-chart of the Bright Up Study. BLT, bright light therapy; DRLT, dim red light therapy; DSM, Diagnostic and Statistical Manual of Mental Disorders.

Behavioral symptoms included sleepiness (A), sleep disturbance (B), depressive symptoms (C), and fatigue (D). Standardized mean differences (SMDs) expressed the differences in depressive symptom reduction between groups. The diamonds indicate the treatment estimates of the total sample. Control interventions included amber, red, or no light therapy.

Flowchart of overview study. DSM = Diagnostic and Statistical Manual of Mental Disorders; BLT = bright light therapy; DRLT = dim red light therapy