The impact of the active components of functional analytic psychotherapy on idiographic target behaviors

Basic behavioral principles (e.g., reinforcement) are compelling candidates for research isolating and evaluating psychotherapy mechanisms of change in contextual behavioral science. Functional Analytic Psychotherapy (FAP) is a contextual behavioral treatment approach that teaches therapists to employ behavioral principles, including the evocation of and contingent responding with reinforcement to client behavior live in session, as its hypothesized mechanism of change. FAP also facilitates generalization of in-session improvements to out-of-session contexts. This study evaluated the effect of the active components of FAP – evoking behavior, contingently responding to behavior, and generalizing improvement – on individual target variables of four clients in an A/A+B design. Relationship building aspects of FAP occurred in the A phase; active components were added in the A+B phase. All clients showed changes in target variables after the phase shift per visual inspection, with largely consistent results using simulation modeling analysis. One client dropped out of treatment after the phase shift. Results provide support for FAP's active components as causing the desired changes and move the research closer to isolating specific behavioral principles as the mechanism of change in FAP. Limitations and cautions are discussed. Published by Elsevier Inc. on behalf of Association for Contextual Behavioral Science