Introduction: Depression is a pervasive mental health disorder characterized by persistent feelings of sadness, loss of interest, and diminished cognitive function. Methodology: The study, approved by the institutional ethics committee, used a quasi-experimental pretest-posttest control group design with a sample size of 150 participants, determined by power analysis. Seventy-five participants were assigned to the experimental group, and 75 to the control group, all meeting the inclusion criteria for depressive disorders. Inclusion criteria included adults aged 18-59, diagnosed with depression (Beck's Depression Inventory), and able to read Tamil and English. Exclusion criteria included individuals with certain medical conditions or severe depression. A non-probability purposive sampling method was used. Results: The experimental group showed significant improvements in biophysiological parameters (pulse rate, respiratory rate, blood pressure, BMI) and biochemical markers (serotonin, dopamine, fasting lipids), along with a reduction in depression (p = 0.008). The control group exhibited no significant changes in these parameters (p>0.05). Conclusion: The study concluded that light therapy is an effective treatment for reducing depression in adult patients. The findings highlight its positive impact on both biophysiological and biochemical parameters related to mental health, particularly in lowering depression levels
Lavanya et al. (2025) studied this question.