Behavior therapy is an approach to the psychological problems based on the philosophy of science known as Radical Behaviorism and also in the behavioral science named Experimental Analysis of Behavior. The purpose of the Radical Behaviorism implies that the behavior of the organisms is ordered and feasible to study scientifically, following the same model of the natural sciences. This approach influences and orients the work of the behavioral therapist, who always intends to discover, with the clients, events in the environment that determine problem-behaviors and what maintains them. Hence, a disorder such as depression is understood as a group of behaviors; for instance, eating and sleep alterations, helpless, excessive crying, suicidal thoughts and others. These behaviors are analyzed through historical episodes and actual situations that are maintaining them. The behavior therapist considers thoughts and feelings as behaviors. They are only different from other types of behavior because the access to them is made by verbal reports of a single person who thinks and feels. Thus, thoughts and feelings are also taken into consideration, analyzed and part of the therapist's interventions.

The behavioral therapist understands that the client is unique and his problems and difficulties are product of an individual history. This approach humanizes the process of therapy because the therapist means to understand each client and each history before any type of intervention. The main instrument of the behavioral therapist is the functional analysis or the rigorous investigation of variables (events, episodes) that are functionally related to the desirable and undesirable behaviors of the client. With this understanding, which is not always easy, it is possible to propose an efficient strategy to aim the well-being and the improvement of the client. The problem-behaviors are treated at the same time that the behavioral therapist works to establish and increase the frequency of behaviors that are adequate to the context, desirable, functional, which generates satisfaction and happiness. The behavior therapy has a considerable set of techniques that comes from researches in laboratories and clinics.

The work of the behavioral therapist involves the sum of the scientific research, rigor on the investigation of information on the initial moment of the process of therapy, as well as the use of reliable techniques and interventions. It brings a considerable result to people that seek this approach.