Research Progress on Light Therapy to Improve Depressive Symptoms of Bipolar Depression

Abstract

Bipolar depression is the predominant and most disabling phase of bipolar disorder, featured by recurrent depressive episodes that impair psychosocial function and quality of life. Conventional pharmacotherapy has limited efficacy and carries a risk of mood destabilization (e.g., affective switch). Light therapy, a nonpharmacological chronotherapeutic intervention, has shown potential to improve bipolar depression symptoms by regulating circadian rhythms and mood regulating neural circuits. This review synthesized domestic and international research advances regarding light therapy for bipolar depression, focusing on the mechanisms of action, clinical efficacy, application protocols, safety, and limitations, aiming to provide evidence based clinical guidance for optimization of therapeutic strategies.