According to Harvard health light therapy can help improve seasonal affective disorder (SAD). It can also be effective for major depression, and depression that occurs during or after late fall and early winter. Light therapy allows the body to be exposed to light for a certain amount of time that then influences the body's natural circadian rhythm, improving mood and sleep patterns by stimulating the production of serotonin and regulating melatonin levels in the brain. Which then can help with heightening your mood and making you feel better overall.