Much of sunlight’s effect on mood is related to the visible light that hits your eyes. Remember, cycles of light and dark affect the production of certain hormones like melatonin, which in turn says a lot about our biological rhythms and moods.igh-powered light-makers (not sun lamps, which emit dangerous ultraviolet radiation) mimic the sun’s effect on your brain, stabilizing serotonin, the chemical related to depression. Exercise also can help by releasing mood-boosting endorphins.