Can cognitive analytic therapy treat hoarding disorder? An adjudicated hermeneutic single‐case efficacy design evaluation

This paper sought to assess whether cognitive analytic therapy (CAT) was effective with a male patient meeting diagnostic criteria for HD who had been nonresponsive to two previous courses of cognitive‐behaviour therapy. An adjudicated hermeneutic single case efficacy design (HSCED) evaluation was undertaken. A rich case record (i.e. a summary document containing the case details, formulations and detailed qualitative and quantitative outcomes) was created. The rich case record was then debated by affirmative (N=3) and sceptic (N=3) research teams. Expert judges (N=3) reviewed the debate and then delivered a final verdict as to whether treatment had worked. Judges unanimously returned a verdict in favour of the sceptic position, concluding that CAT had not enabled change. Lack of change on the primary nomothetic hoarding outcome measure was particularly influential in the final judgement. In this case of HD, CAT was therefore not effective as an intervention. More research is needed before any definitive conclusions can be drawn however as to the wider utility of CAT with HD. Methodological limitations are outlined, alongside considerations for future research.