Depression can be caused by things like stressful life events, certain medications, death of a loved one, hormonal changes, and of course, caused by faulty mood regulation in the brain.

　　忧郁的形成原因包含令人压力很大的人生经历、一些药物、至亲挚爱的过世、荷尔蒙的变化，还有当然，源于脑中情绪的调节失常。