Serotonin is 1 of 7 neurotransmitters in the brain responsible for HAPPINESS. Serotonin plays quite a few roles in the body, but as it relates to happiness, it is often referred to as the confidence molecule. Higher serotonin levels boost self esteem and self worth so lower levels can sometimes lead to feelings of depression. Since the brain cannot fully distinguish between thoughts and actions, in order to boost your levels, just think and recall times when you felt great about yourself! To me, Happiness really represents balance in life and so the Yin Yang base of this pendant is perfect! This is my favorite design to date. Let this pendant be a reminder to think Happy and Confident thoughts to boost your Serotonin levels