A common ingredient underlying the success of diverse psychotherapies is the

A) professional training and experience of the therapist.
B) escape from real-life pressures offered by psychotherapy.
C) length of time the client spends in psychotherapy.
D) client's expectation that psychotherapy will make things better.

The client's expectation that psychotherapy will make things better is a common ingredient underlying the success of diverse psychotherapies. This is known as the placebo effect, and research has shown that a client's belief in therapy and positive expectations can lead to improvements in their psychological well-being, regardless of the specific type of therapy or the skill level of the therapist. The other choices, such as the professional training and experience of the therapist or the length of time spent in therapy, may be important factors in the success of psychotherapy but are not as consistently present across different types of therapy.