Bright light therapy is an effective treatment in seasonal affective disorder either alone or adjacent to antidepressant drugs. BLT is also effective in non-seasonal depressive patients. A study was conducted in NPIstanbul Neuropsychiatry Hospital to examine the efficacy of bright light therapy on sleep quality as well as the effects on mood in non-seasonal depression. Seven drugfree patients and 10 patients who were also started a SSRI treatment were included in the study. Bright light therapy was administered to the patients at 10,000 lux for 30 minutes for seven days. HAM-D, BDI, POMS survey, and PSQI were administered before and after bright light therapy. Among the patients who were administered BLT and SSRIs, HAM-D, BDI, POMS depression, fatigue, confusion, total mood disturbance, PSQI total and sleep latency scores lowered before than after BLT. Among drug-free patients, PSQI sleep disturbance subscale score was lower before than after BLT. Sleep latency was shorter post treatment period in comparison to baseline scores. This study suggests that BLT is effective in subjective sleep quality as well as depressive mood in non-seasonal depression alone or when combined with SSRIs.