Depression is a serious yet common psychological condition that changes how you think and feel and also affects your social behavior and sense of physical well-being. We have all felt sad at one time or another, but that is not depression. Sometimes we feel tired from working hard, or discouraged when faced with serious problems. This too, is not depression. These feelings usually pass within a few days or weeks, once we adjust to the stress. If these feelings linger, intensify and begin to interfere with work, school or family responsibilities, then it may be depression. Each year over 6% of American adults experience a period of clinical depression. Depression is 2-3 times more common in women than in men, in part because women's brains make less of the "happy" hormone, serotonin. Depression, which can affect anyone, is often not recognized because many of the symptoms such as sleep and appetite disturbances mimic physical illness. Once identified, most people diagnosed with depression can be successfully treated. Too often, untreated or inadequately treated depression results in suicide or the destruction of family life. The more serious the condition, the greater the importance of seeking medical and psychological help.

Major depression often begins between the ages of 15 and 30 and episodes typically recur. One diagnostic criteria for major depressive disorder is:

• The patient has depressed mood (e.g., sad or empty feeling) or loss of interest or pleasure most of the time for 2 or more weeks plus 4 or more of the following symptoms (SIGECAPS):
  Sleep - Insomnia or hypersomnia nearly every day
  I nterest - Markedly diminshed interest or pleasure in nearly all activities most of the time
  Guilt - Excessive or inappropriate feelings of guilt or worthlessness most of the time
  Energy - Loss of energy or fatigue most of the time
  Concentration - Diminished ability to think or concentrate; indecisiveness most of the time
  Appetite - Increase or decrease in appetite
  Psychomotor - Observed psychomotor agitation/retardation
  Suicide - Recurrent thoughts of death/suicidal ideation
• The symptoms do not meet crieteria for mixed episode (major depressive episode and manic episode)
• The symptoms cause clinically significant distress or impairment in social, occupational, or other improtant areas of functioning
• The symptoms are not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a general medical condition
• The symptoms are not better accounted for by bereavement