Negative effects in randomized controlled trials of psychotherapies and psychological interventions: A systematic review

Background: Psychotherapy is a key evidence-based method for the treatment of mental disorders. However, little research has been published on the negative effects of psychotherapies. Aims: We examined this issue through a systematic literature review of previous systematic reviews on randomized controlled trials (RCTs). Methods: We focused on previous reviews and meta-analyses on 1) RCTs examining the effectiveness of psychotherapies and 2) previous reviews and meta-analyses specifically focusing on the negative effects of psychotherapy. We included publications published in PubMed and the Cochrane Databases from the year 2000 or later. Results: Of the 1,430 relevant publications, only a small proportion (30%) mentioned negative outcomes, mostly withdrawal. Only 57 of the extracted original studies monitored potential negative effects, and only three small-scale studies indicated negative effects. Conclusions: The systematic monitoring of negative effects in psychotherapy has not been given the same attention as has been given to the benefits of therapy.