ISTDP is a Functional Analytic Psychotherapy

In this paper, I describe and analyze Intensive Short-Term Dynamic Psychotherapy (ISTDP) from the perspective of Functional Analytic Psychotherapy (FAP), a behavioral psychotherapy explicitly emphasizing the therapeutic relationship as the primary context for clinical intervention. I propose that FAP can be understood as a generalized system of behavioral psychotherapy, characterized by procedural guidelines (“FAP’s Five Rules”) derived from operant conditioning principles. Further, I demonstrate that ISTDP, despite its psychoanalytic origins, procedurally fulfills the criteria of this generalized behavioral system, particularly through its structured use of contingent responding (Pressure, Challenge, Head-On Collision) within therapeutic interactions. ISTDP’s implicit universal conceptualization of emotional health — emphasizing adaptive emotional experiencing, expression, and interpersonal closeness — is explicitly articulated within the behavioral framework. Highlighting complex clinical phenomena of ISTDP, such as emotional breakthroughs (“unlockings”) and the expressions of the Unconscious Therapeutic Alliance (UTA), I argue that these phenomena challenge purely operant behavioral explanations and thus suggest the potential benefit of integrating advanced behavioral theoretical frameworks like Relational Frame Theory. The paper discusses implications for theoretical advancement, clinical practice refinement, and improved empirical research in ISTDP.