Randomised controlled trial of the effectiveness of group cognitive behavioural therapy for psychosis

Abstract

Cognitive behavioural therapy for psychosis (CBTp) has been shown to be effective in managing distressing positive psychotic symptoms such as delusion and hallucination. CBTp is therefore recommended to be provided to people suffering from persistent positive psychotic symptoms. However, little evidence is available about presenting CBTp in a group format, which is a cost effective way to improve patients’ access to psychological services. Besides, most of the studies of group CBTp were done in Western countries; evidence about the effectiveness of group CBTp is thus highly inadequate in the Asian context.

The aims of the present study are to explore the utility of group CBTp in the Asian context and its effectiveness on positive psychotic symptoms using a randomised controlled trial.

This study was conducted in the out-patient and day-patient units of the Department of Psychiatry, Kowloon Hospital, Hong Kong. Patients in this study were referred by their treating psychiatrist and were randomised to receive either group CBTp plus treatment as usual or to receive psychoeducation intervention (PsyEdI) plus treatment as usual. Both the group CBTp and PsyEdI consisted of 7 consecutive weekly sessions with a booster session 4 weeks after the last session. Patients were asked to complete different outcome measures including a Beck Depression Inventory II (BDI-II), a Beck Anxiety Inventory (BAI), a Chinese version of the Beliefs About Voice Questionnaire-Revised version (BAVQ-R), a Chinese version of the Beck Cognitive Insight Scale (BCIS), as well as a Chinese version of the Southampton Mindfulness Questionnaire. They were also interviewed by a clinical psychologist using the Psychotic Symptom Rating Scales (PSYRATS) to assess their delusion and hallucination. All the assessments were conducted both before the start of and after the end of the intervention.

Participants receiving group CBTp (n=25) showed significantly greater improvement in their delusion and had a more positive trend in their hallucination than those receiving PsyEdI (n=23). Group CBTp was also found to be effective in reducing patients’ dysfunctional beliefs towards voices, especially in the subscale of benevolence and omnipotence, as well as their conviction on delusion. Moreover, participants in the group CBTp was found to have a significant reduction in their distress from positive psychotic symptoms.

The study revealed that group CBTp can be effective in improving positive psychotic symptoms to those patients with persistent distressing psychotic experiences. Group CBTp could be considered as an effective adjunctive psychological intervention to patients with psychosis and be feasible for application in routine clinical practice.