Depression is a mental health illness that affects one in 10 Americans.More than just feeling down, clinical depression is a mood disorder characterized by persistent feelings of sadness, hopelessness, and worthlessness that don’t go away on their own. It is essential to recognize that feeling down on occasion is a normal – and important – part of life. Sad and distressful events occur in everyone’s life, and responding to them emotionally is healthy. However, feeling miserable consistently and without any sense of hope is not normal, and should be treated as a serious medical condition.