Psychotherapy outcome research: Implications of a new clinical taxonomy

Abstract

Since the publication of DSM-III in 1980, the scientist-practitioner gap in clinical psychology has expanded, as almost all outcome research in clinical psychology has been on diagnosed mental disorders within a medical model using drug trial methodologies, whereas most practising clinicians undertake functional analyses and case formulations of clinical psychological problems (CPPs) and then apply tailored interventions within an ongoing hypothesis-testing methodology. But comparatively reliable assessment and generalizable conclusions in psychotherapy outcome research require a comprehensive theory-derived conception or operational definition of 'CPPs', standardized functional analyses, and a taxonomy of CPPs comparable to DSM's listings of mental disorders. An alternative conception and taxonomy of CPPs have recently been proposed, offering improvements in the reliability and generalizability of case formulation-based psychotherapy outcome research. It conceives of CPPs as instances of the formation and operation of self-sustaining problem-maintaining circles (PMCs) of psychological-level causal elements-that is, at the level of cognitions, behaviours, emotions, and events or situations (stimuli). The paper describes this new conception of CPPs, a subsequent nascent taxonomy of evidence-based PMCs which standardizes the underlying mechanisms that maintain CPPs, and ensuing benefits to research (as well as to practice) in clinical psychology. These benefits include being able to encompass all treatment-worthy CPPs, not just diagnosable mental disorders; to assess theory-derived intervention strategies, not just arbitrary therapy bundles; and to directly feed back into psychological theories, not just expand an atheoretical list of patented "evidence supported therapies."

Keywords: case formulation; clinical psychological problems; outcome research; problem-maintaining circles; taxonomy; transdiagnostic.