A pilot trial of cognitive behavioural therapy for interpersonal sensitivity in individuals with persecutory delusions

BackgroundAdvances in understanding delusions may be used to improve clinical interventions. Interpersonal sensitivity – feeling vulnerable in the presence of others due to the expectation of criticism or rejection – has been identified as a potential causal factor in the occurrence of persecutory delusions. The purpose of this study was to examine the potential impact on persecutory delusions of a (newly devised) cognitive behavioural intervention targeting interpersonal sensitivity (CBT-IPS).MethodsCBT-IPS was tested in an uncontrolled pilot study with eleven patients with persistent persecutory delusions in the context of a psychotic disorder. Patients had two baseline assessments over a fortnight period to establish the stability of the delusions, which was followed by six sessions of CBT-IPS, a post-therapy assessment, and a further follow-up assessment one month later.ResultsInterpersonal sensitivity and the persecutory delusions were stable during the baseline period. At the post-therapy assessment there were significant reductions of large effect size for both interpersonal sensitivity and the persecutory delusions. These gains were maintained at follow-up.LimitationsThe main limitation is that in this initial test there was no control group. The intervention may not have caused the reduction in delusions. Further, bias may have been introduced by the outcome data being collected by the therapist.ConclusionsThe findings from this evaluation are consistent with the hypothesised causal role for interpersonal sensitivity in the occurrence of persecutory delusions. CBT-IPS shows promise as a therapeutic intervention but requires a rigorous test of its efficacy.