Contextualizing the negative effects of psychotherapy

Clinical recommendations and informed decision-making require an evidence-based understanding of psychological treatment’s potential benefits and risks. Whereas psychotherapy outcome research has traditionally focused primarily on the positive effects of treatments, the number of publications on negative effects has rapidly increased over the past decade. In this Review, we shed light on the potential risks of psychotherapy and discuss the challenges associated with their contextualization. Based on an overview of the current core definitions of the negative effects of psychotherapy, we propose an initial conceptualization of the most frequently used terms with a particular focus on the distinction between the negative effects of a correctly applied treatment and the reactions to incorrectly applied psychotherapeutic interventions and malpractice. We further describe assessment methods that measure negative effects from different perspectives and sources (the patient, the therapist and the relatives) and current evidence on the frequency of negative effects of psychotherapy from different study designs (randomized controlled trials, naturalistic studies and retrospective survey research). We discuss recommendations for therapist training, research and clinical practice to better understand, detect and prevent negative effects of psychotherapy and contribute to improving patient safety.