Psychological therapies and safety: “there is no evidence of iatrogenic harm” is not the same as “there is evidence of no iatrogenic harm”

Evidence-based healthcare requires integration of data on both efficacy and treatment-related harm. In research on psychological therapies, treatment-related harm remains inconsistently defined, inadequately monitored, and under-reported, resulting in an asymmetrical evidence base that limits valid risk-benefit evaluation and informed consent. Evidence indicates that only a minority of clinical trials systematically assess treatment-related harm, contributing to under-detection, while qualitative and lived experience-informed research consistently documents distressing and harmful therapeutic experiences across modalities and populations.Quantitative evidence further suggests that the occurrence of treatment-related harm is unlikely to be rare, although prevalence estimates vary substantially because of inconsistent definitions and measurement approaches. Methods for defining and monitoring treatment-related harm are now available but remain insufficiently implemented in research and clinical practice. These limitations are compounded by inadequate integration of lived experience expertise and limited representativeness in trial populations.Current evidence therefore remains insufficient to comprehensively establish the safety of psychological therapies commonly referred to as evidence-based. Advancing the field requires prospective definitions of treatment-related harm, routine monitoring, transparent reporting, and meaningful integration of client-reported and lived experience perspectives.