Depression is one of the most common mental illnesses in the United States, affecting more than 16 million men and women (almost 6.7 percent of the adult population) and 3.1 million adolescents.
It is a serious mental illness in which feelings of sadness, hopelessness, loss of interest, anger, frustration, or other negative emotions like irritability (especially in adolescents) last for weeks or years and interfere with daily life.
All people experience moments when they feel sad or blue, but these feelings usually pass within a couple of days and are not indicative of depression.
Depression can cause deep emotional pain both to the person experiencing it and, often, to that person’s close family and friends.
Depression is a significant public-health issue. It is the leading cause of disability in the United States for people between ages 15 and 44 and is the number one cause of injury or illness for men and women around the world. People with depression are more likely to die from suicide as well as from other illnesses, such as heart disease.