There’s something magical in those dark squares, and they have nothing to do with your imagination. Benefits of dark chocolate. For one, they boost serotonin levels in the brain. Known as the feel-good hormone, serotonin plays a key role in combating anxiety and depression. Chocolate can also affect dopamine levels, thereby controlling the brain’s reward and pleasure centers. Gone are the days of ‘an apple a day keeps the doctor away’. Switch over to ‘a bite at night keeps you perfectly alright!’ Let’s dive a little further into the details.