Cognitive therapy for command hallucinations: randomised controlled trial.
BACKGROUND: Command hallucinations are a distressing and high-risk group of symptoms that have long been recognised but little understood, with few effective treatments. In line with our recent research, we propose that the development of an effective cognitive therapy for command hallucinations (CTCH) would be enhanced by applying insights from social rank theory. AIMS: We tested the efficacy of CTCH in reducing beliefs about the power of voices and thereby compliance, in a single-blind, randomised controlled trial. METHOD: A total of 38 patients with command hallucinations, with which they had recently complied with serious consequences, were allocated randomly to CTCH or treatment as usual and followed up at 6 months and 12 months. RESULTS: Large and significant reductions in compliance behaviour were obtained favouring the cognitive therapy group (effect size 1.1). Improvements were also observed in the CTCH but not the control group in degree of conviction in the power and superiority of the voices and the need to comply, and in levels of distress and depression. No change in voice topography (frequency, loudness, content) was observed. The differences were maintained at 12 months' follow-up. CONCLUSIONS: The results support the efficacy of cognitive therapy for CTCH.