In recent decades, the study of psychotherapy effectiveness has been one of the pillars of clinical research because of its implication for therapeutic cure. However, although many studies have focused their interest on the patient's perception, there are no instruments oriented to the study of psychotherapists' attributions of effectiveness: to what factors psychotherapists attribute responsibility for the cure of the therapies they provide. The present study aimed to develop and validate an instrument for assessing the attribution of the effectiveness of psychotherapy in a population of 69 psychotherapists of different theoretical orientations. After an initial process of inter-judge content validation, 12 items were selected for validation in the targeted population, adequately fulfilling the quality requirements in the validity-reliability tests, and grouped into four factors after principal component analysis. These factors were as follows: (1) therapeutic alliance enhancers; (2) psychotherapist emotional characteristics; (3) therapy-specific variables; and (4) facilitators of patient engagement with therapy. This four-factor structure also showed a good fit for the fit indices checked in confirmatory factor analysis. In summary, we can conclude that the Psychotherapeutic Effectiveness Attribution Questionnaire (PEAQ-12) developed in our research can be helpful if tested on a larger number of individuals. The results can be replicated in other populations of psychotherapists.
Keywords: attribution; development; psychotherapist; scale; validation.