Causal Effects In Psychotherapy: Counterfactuals Counteract Overgeneralization

Abstract

Causal inference of psychotherapy effects is usually based on the theory of internal and external validity. The authors argue that as an inductive strategy it often leads to overgeneralization because it promotes neglect of specific clinical boundary conditions (such as practically relevant combinations of treatments, settings, patients, and therapists). Adding the counterfactual conceptualization of causal effects counteracts overgeneralization by considering individuals at a fixed time under two possible treatment conditions as basic units of a causal effect. Consequently, causal effects are regarded as varying in nature as local pieces of a global theory. The authors outline the main deductions from the counterfactual conceptualization with regard to understanding causality, average effects, bias, and study design and address some controversies in psychotherapy research.

RÉSUMÉ

L'inférence causale des effets de la psychothérapie est généralement basée sur la théorie de la validité interne et externe. Les auteurs soutiennent qu'en tant que stratégie inductive, elle conduit souvent à la surgénéralisation, car elle encourage la négligence des conditions spécifiques de la clinique (telles que les combinaisons pertinentes de traitements, le cadre thérapeutique, les patients et les thérapeutes). En ajoutant la conceptualisation hypotético-déductive des effets causaux, cela neutralise la surgénéralisation, en considérant les individus à un moment précis selon deux conditions de traitement possible comme unités de base d'un effet de causalité. Par conséquent, les effets de causalité sont considérés comme variables par nature, comme des pièces locales d'une théorie globale. Les auteurs décrivent les principales déductions de la conceptualisation hypothético-déductive pour la compréhension de la causalité, les effets moyens, les biais et le plan d’étude, et discutent certaines controverses dans la recherche en psychothérapie.

Abstract

A Inferência causal dos efeitos da psicoterapia é geralmente baseada na teoria da validade interna e externa. Os autores argumentam que, sendo uma estratégia indutiva, geralmente conduz à sobregeneralização porque promove a negligência de determinadas condições clínicas especificas (como as combinações praticamente relevantes de tratamentos, de definições, de pacientes e terapeutas). Acrescentando a conceptualização contrafactual dos efeitos causais, neutraliza-se a sobregeneralização ao considerar indivíduos num determinado tempo sob duas condições de tratamento possíveis como unidades básicas de um efeito causal. Consequentemente, efeitos causais são considerados como variáveis na natureza, como peças locais de uma teoria global. Os autores salientam as principais deduções da conceptualização contrafactual para compreender a causalidade, os efeitos habituais, o viés, o desenho de estudo e para abordar algumas controvérsias da investigação em psicoterapia.

Abstract

Keywords:

• statistical methodology
• technology in psychotherapy research and training
• process research
• integrative treatment models
• causality
• validity

Acknowledgements

Michael Höfler, Andrew T. Gloster, and Jürgen Hoyer, Institute of Clinical Psychology and Psychotherapy, Technische Universität Dresden, Dresden, Germany.We wish to thank Frank Jacobi and Sabine Schönfeld (Dresden) as well as the anonymous reviewers for helpful comments on earlier versions of this article.

Additional information

Notes on contributors

Jürgen Hoyer

Michael Höfler, Andrew T. Gloster, and Jürgen Hoyer, Institute of Clinical Psychology and Psychotherapy, Technische Universität Dresden, Dresden, Germany