The most effective type of therapy is cognitive therapies. It emphasizes rational thinking as the key to treating a mental disorder. This prevents a lot of negativity, which is what leads to depression. The therapists job is to help the client learn more positive ways of thinking. Symptoms disappear as positive thoughts replace the old negative thoughts. The least effective is group therapies. This is when the is more than one client with a therapist at a time. These are usually couple counseling, or A.A. groups. These give the multiple clients an opportunity to observe and initiate new social behaviors in forgiving, supportive atmosphere. Allowing people to talk with other people who have the same problem. I don't believe this kind of therapy
