Adverse experiences in psychological treatments: Where do we stand?

The article specifically focusses on adverse experiences and negative effects related to psychotherapy that, though occasionally discussed, have received increasing attention during the last decades. It summarizes the current state of research related to conceptualizations of adverse experiences, their assessment and some data on their prevalence with a specific view on different sources of knowledge about adverse events in psychotherapy. These reach from case reports, patient complaints, clinical trials, patients' and therapists' reports and surveys as well as studies in random samples. Currently, we can detect more open questions than answers. Some research issues of potential priority will be mentioned.