A randomized controlled trial of group cognitive-behavioral therapy vs. enhanced supportive therapy for auditory hallucinations

Abstract

There has been little research examining group cognitive-behavioral therapy (CBT) for schizophrenia, especially compared to an active control treatment. The purpose of this study was to investigate the effectiveness of group CBT for auditory hallucinations compared to an enhanced supportive therapy (ST). Sixty five participants with schizophrenia spectrum disorders and persistent hallucinations were randomly assigned to group CBT or enhanced group ST. Primary outcomes focused on beliefs about voices and global auditory hallucinations severity. Secondary outcomes included psychotic symptoms, self-esteem, social functioning, insight, depression, and hospitalization. Controlling for baseline levels, these outcomes were evaluated across post-treatment, 3 month and 12 month follow-ups. Participants who received enhanced ST were less likely to both resist voices and to rate them as less malevolent through 12-month follow-up relative to participants who received CBT. Group CBT was associated with lower general and total symptom scores on the PANSS through 12-month-followup relative to participants who received enhanced ST. Outcomes improved through 12-month follow-up in both therapy groups, with enhanced ST having more specific impact on auditory hallucinations, and CBT impacting general psychotic symptoms.

Introduction

Hallucinations are a common feature in schizophrenia. In fact, over 60% of people with a diagnosis of schizophrenia experience a hallucination at some time over the course of their illness (Slade and Bentall, 1988). Although pharmacological treatments remain the front-line treatment for schizophrenia (Lehman et al., 2004), limitations such as non-compliance and persistent residual positive symptoms have led researchers to seek out ancillary treatments (Fenton et al., 1997, Pantelis and Barnes, 1996). In this regard, individual cognitive-behavioral therapy (CBT) has proven to be an effective strategy in the treatment of positive and negative symptoms of schizophrenia (Farhall et al., 2007, Pilling et al., 2002, Rector and Beck, 2002, Wykes et al., 2008).

Unfortunately, CBT is not widely accessible to persons with schizophrenia (particularly in the United States). This has prompted researchers to examine more efficient ways of delivering this intervention, such as group therapy (Mueser and Noordsy, 2005), which has comparable effect sizes to individual CBT for psychosis (Wykes et al., 2008). Group CBT for auditory hallucinations has been shown to reduce negative beliefs about voices (and voice severity) in a pilot open trial (Pinkham et al., 2004), to reduce the distress associated with auditory hallucinations in individuals early in their psychotic illness relative to wait-list controls (Newton et al., 2005), and to reduce overall symptoms and auditory hallucinations, and increase insight in a chronically ill sample (Wykes et al., 1999). However, these findings were not replicated in a follow-up study that compared group CBT to treatment as usual, instead finding that CBT was associated with improved social functioning (Wykes et al., 2005). In addition, the effectiveness of group CBT for auditory hallucinations has not been examined in the context of an active comparison treatment condition. Thus, the aim of this study was to evaluate the effectiveness of group CBT for auditory hallucinations compared to an enhanced supportive therapy (Penn, 2004). Our primary hypothesis was that group CBT would have a stronger impact on auditory hallucinations than group ST (i.e., on distress and negative beliefs surrounding auditory hallucinations). A secondary hypothesis is that group CBT would be superior to group ST in reducing psychotic and general symptoms (due to the teaching of cognitive behavioral coping strategies), improving insight, and reducing hospital readmission rates. There were no a priori hypotheses concerning social functioning or self-esteem.