Introduction to the special section: the case for training in the provision of psychological therapy.

Recent trends, such as the national health care initiative, have brought into focus the importance of identifying the qualifications of those who provide mental health services. This special section explores the research evidence for the value of professional training among those who provide psychological therapy. The set of articles describe what is known about the relationship to therapeutic efficacy of professional training, training in ethnic diversity, and clinical supervision. These articles suggest that professional training enhances clinical efficacy, especially if type of training, setting of practice, and nature of patient problems are considered. They also suggest that supervision and specific training in ethnic diversity enhance knowledge and sensitivity among psychotherapists. It is anticipated that this special section will promote a dialogue about these conclusions.