Functional Analytic Psychotherapy (FAP), based on the principles of radical behaviorism, emphasizes the
impact of eventualities that occur during therapeutic sessions, the therapist-client interaction context, functional
equivalence between environments, natural reinforcement and shaping by the therapist. This paper reviews recent
studies of FAP from the published literature and classifies them into different categories, i.e., 1) integration with
other therapies, 2) supervision and improvement of therapeutic skills, 3) methods for evaluation and data recording
in therapy, 4) effectiveness and efficacy, 5) the relationship between thoughts and emotions, and 6) application to
clinical problems and new types of application.