Case Formulation Quality As a Predictor of Psychotherapy Treatment Response

Psychotherapy case formulation is described as a working hypothesis concerning the causal influences associated with an individual\u27s psychological problems. Case formulations are meant to integrate large amounts of complex and often contradictory information, providing a coherent and meaningful understanding of the individual patient, and guiding the selection of appropriate treatment goals and interventions. Case formulation is thought to be especially helpful in understanding complex psychotherapy cases, including those in which multiple, intertwined problems coexist, interpersonal issues threaten to interfere with formation of the therapeutic alliance, or treatment resistance is very high. Surprisingly, while logic argues that the quality of a case formulation will be positively associated with treatment response, this assumption has not yet been tested empirically. Further, although the ability to construct an effective case formulation has long been considered a core clinical skill, little research has been done to identify the characteristics that define an effective formulation. Based on a review of the literature, four characteristics were selected to represent pantheoretical aspects of quality in case formulations: comprehensiveness, complexity, coherence, and specificity. Following procedures outlined in a manual constructed for this study, 81 written case formulations were rated for quality. Mean ratings for each formulation were used in regression analyses designed to predict treatment outcome. In addition, intake distress levels and comorbidity were examined for their potential as modifiers of that relationship. Results indicated that interrater reliability of case formulation quality ratings was moderately high, suggesting acceptable reliability. A small positive relationship was observed between quality ratings and treatment response. The relationship between case formulation quality ratings and treatment response was stronger for individuals who were diagnostically complex. This suggests that the usefulness of a written case formulation is at least partially dependent on clinical characteristics of the patient that may be assessed at intake. The findings of this study are important for two reasons. First, a method of reliably rating the quality of case formulations that may generalize across different theoretical orientations was developed. Second, this is the first study to provide empirical evidence for the clinical utility of case formulation