Psychological treatment of depression (psychotherapy) assists the depressed individual in several ways. First, supportive counseling helps ease the pain of depression, and addresses the feelings of hopelessness that accompany depression. Second, cognitive therapy changes the pessimistic ideas, unrealistic expectations, and overly critical self-evaluations that create depression and sustain it.
Unfortunately, many poorly trained counselors never move beyond providing supportive counseling. This alone will not eliminate the depression. As a result, the depression, and the therapy, continues indefinitely, with little improvement. Supportive counseling "feels" helpful, and as part of the overall treatment plan does help. But, unless the depressed person makes critical life changes, the depression will continue.
These changes are both internal and external. Internal changes are usually needed in problem assessment, self-evaluation, the evaluation of others, and the expectations the depressed person has for himself/herself, others and about life. External changes may be needed in problem solving skills, stress management, communication skills, life management skills, and the skills needed to develop and sustain relationships.
The length of treatment will vary, according to the severity of the depression, and the number and kind of life problems that need to be addressed. Most people will begin to experience some relief with 6 to 10 sessions, and approximately 70-80% of those treated notice significant improvement within 20-30 sessions. Mild depression may be treated in less sessions, and more significant depression may require extended treatment.