Impaired decentration in personality disorder: a series of single cases analysed with the Metacognition Assessment Scale.

Background: There is growing support for the idea that an impaired understanding of others' mental states is an underlying feature of personality disorder (PD). Only recently has there begun to be evidence of impairments to subjects' ability to infer and reason about others' intentions and emotions, and detach from their own perspective when doing so.

Method: We analysed the transcripts from the first 16 psychotherapy sessions of 14 PD patients. Scales for understanding others' minds from the Metacognition Assessment Scale were used.

Results: Patients were generally able to describe others' mental states, although, at times, they had problems. There was, on the other hand, an inability to decentre while reasoning about others, and this was common to all the patients.

Conclusions: PDs indeed feature a poor decentration, which is not easily identified with the usual lab tasks. Implications for further research and treatment are discussed.

Key Practitioner Message: *Patients with personality disorders have substantial difficulties in adopting others' point of view and standing back from their own, and grasping that they are not the center of other peoples' thoughts.