psychotherapy

What is the difference btw. art technique of psychotherapy and agreed to produce a placebo effect?
How can we determine if the result is caused by the belief of a person, not art?
With an accepted technique of psychotherapy, there is evidence that supports a direct link to the methods and results. For example, systematic desensitization has been shown to have a direct interest in the treatment of phobias. A placebo effect suggest a positive effect not directly related to the methods used. Placebo is much more dependent on the person hope or expectation that treatment will be beneficial rather than the specific technique used.
Anxiety Treatment: Psychotherapy