Cognitive behaviour therapy to prevent harmful compliance with command hallucinations

West MidlandsMental Health
Published Date: 1 Jul 2014

Cognitive behaviour therapy to prevent harmful compliance with command hallucinations


  • Command hallucinations are among the most distressing, high-risk and treatment-resistant symptoms for people with psychosis. However, no evidence-based treatments are available to reduce this behaviour. 
  • A new cognitive therapy has been tested to challenge the perceived power of voices to inflict harm if commands are not followed, thereby reducing the motivation of the hearer to comply. 
  • A single blind, randomised control trial was conducted with participants from three centres in the UK. Participants who had command hallucinations for at least 6 months leading to major episodes of harm to themselves or other people were assigned to either cognitive therapy for command hallucinations as well as treatment as usual, or treatment as usual only for nine months. 
  • The aim of the trial was to assess the acceptability, effectiveness and cost-effectiveness of cognitive therapy for command hallucinations.


  • Of 197 participants, 98 were assigned to cognitive therapy for command hallucinations and treatment as usual, while 99 were assigned to treatment as usual. At 18 months, 46% of participants in the treatment as usual group continued to fully comply with the voices, compared with 28% in the cognitive therapy and treatment as usual group (P=0.021).
  • The results provide evidence of substantial reductions in harmful compliance, at least in people who have complied with florid hallucinations. 
  • This is the first large -scale trial to test the effect of cognitive behaviour therapy on harmful behaviour, rather than overall psychosis symptoms. These results resolve the uncertainty about the effectiveness of cognitive behaviour therapy in reducing harm from commanding hallucinations.  
  • More complex trials are now needed to identify the most influential components of the treatment in reducing power and compliance. Further papers will be published providing a more complex analysis, alongside results of a health -economic analysis.