In the fields of psychology and psychiatry, the terms depression or depressed refer to sadness and other related emotions and behaviors. It can be thought of as either a disease or a syndrome.

The Diagnostic and Statistical Manual of Mental Disorders (DSM) states that a depressed mood is often reported as feeling sad, helpless, and hopeless. In traditional colloquy, "depressed" is often synonymous with "sad," but both clinical depression and non-clinical depression can also refer to a conglomeration of more than one feeling.

For more information about Depression (mood), read the full article at Wikipedia.
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