Depression is a psychological disorder in which a person is overwhelmed by an emotional crisis Symptons of depression include feelings of hopelessness sadness and despair loss of interest and pleasure in things weight loss or weight gain difficulty fallin

Depression is a psychological disorder in which a person is overwhelmed by an emotional crisis. Symptons of depression include feelings of hopelessness, sadness, and despair; loss of interest and pleasure in things; weight loss or weight gain; difficulty falling asleep or sleeping more than usual; lack of motivation; and loss of energy. Agrowing body of evidence suggests that several types of depression are linked to biological and environmental factors. In cases of mild or situational depression, the symptoms usually decline with a change of scenery or routine, or when the problem that caused the depression disappears.

The professor describes seasonal affective disorder - SAD. Explain how SAD is an example of depression.