“Why N=1?”: An Overview of the Clinical Case Study Method and Guidelines for Psychotherapists

Abstract

This article examines the method of clinical case study in psychotherapy, with the aim of evaluating its place within the contemporary psychological and psychotherapeutic scientific discourse and defining its methodological and epistemological potential. Drawing on the longstanding critique of single-case (N=1) research, most commonly based on arguments of limited generalisability, the article proposes that such evaluations fail to adequately reflect the methodological specificity and epistemic value of clinical case studies. The first part of the article presents the development of the case study method, from early anthropological research to the psychoanalytic tradition, in which, the case study became established as a central form of theory construction and clinical thinking. Contemporary developments in case study research are also discussed, highlighting the importance of clinical case studies due to their capacity to maintain a close connection with everyday therapeutic practice. In the second part of the article, drawing on a clinical example, the article demonstrates how single-case analysis enables a systematic and multi-layered examination of the patient’s experience, the dynamics of the therapeutic relationship, diagnostic reasoning, and the functioning of theoretical assumptions within a specific clinical context. The article presents recommendations for writing clinical case studies, addressing key structural, methodological, and ethical aspects. The clinical case study method is thus understood not as an alternative or secondary approach, but as an essential form of knowledge in psychotherapy, enabling the investigation of complex psychological phenomena within their unique context.