According to the National Institute of Mental Health, an estimated 17 million adults experience depression during any one-year period in the United States and Puerto Rico. The major problem is that many people don't recognize they have a condition that can be treated very effectively.
Most people feel sad or blue on occasions.
They feel grief over upsetting life experiences, such as sickness, job loss, death in the family, and separation or divorce. These feelings tend to become less intense on their own as time goes by. Depression usually occurs when feelings of extreme sadness last for at least two weeks or longer, interfering with such daily living activities as working, sleeping, and eating. Many depressed people tend to feel hopeless and helpless, and some may think about death or suicide. Depressed people may become overwhelmed and exhausted, and will stop participating altogether in certain everyday activities.