A review of hearing voices groups: evidence and mechanisms of change.

As a heavily stigmatized group, voice hearers often value the chance to meet others with similar experiences. As a result, Hearing Voices Groups (HVGs) are becoming increasingly common in both inpatient and outpatient settings. Where resources are constrained, HVGs are frequently viewed as a desirable alternative to individual therapy and are often preferred by service users themselves. HVGs often vary in their content and structure, with four common approaches: CBT, skills-training, mindfulness and unstructured support groups. This review evaluates the evidence for HVGs and the mechanisms of change for successful interventions. CBT was the only approach with evidence from well-controlled studies. However, several evidence-based treatments share 'key ingredients' which evidence suggests help reduce distress. Successful groups supply a safe context for participants to share experiences, and enable dissemination of strategies for coping with voices as well as considering alternative beliefs about voices. Future research should focus on isolating mechanisms of change and predictors of outcome in order to refine HVG approaches, rather than polarizing them and setting them against one another in efficacy trials.