A service evaluation of psychodynamic psychotherapy for people with intellectual disabilities

Abstract

The evidence base for psychodynamic psychotherapy for people with intellectual disabilities (ID) is mainly made up of case studies with a small number of open trials without control (Beail, 2016) and the development of the evidence base for psychological therapies is a priority. In this service evaluation, we estimated the significance and effect size of psychodynamic intervention in 66 cases from the time of assessment to case closure, using the Health of the Nation Outcome Scales for Learning Disability (HoNOS-LD). A significant and sizeable effect from assessment to case closure was detected on HoNOS-LD Total Score, with similar effects on subscale Factor Scores. A waiting list control condition for a smaller subset did not find significant overall change, and cases remaining within the service following intervention showed no deterioration after therapy. A relatively low number of sessions was required on average (13.7; median=8) but a dose-effect relationship was observed with more change associated with more sessions. We consider the shortcomings of this study and make recommendations for improved design of further studies.