Aim: To provide an updated of recent findings about efficacy of cognitive-behavior therapy (CBT) in reduction of command hallucinations.
Methods: PubMed/MEDLINE, Cochrane Library, the Cumulative Index to Nursing and Allied Health Literature, PsycINFO, ClinicalTrial.gov searches were performed using the keywords "hallucinations", "behavioural therapy" and " cognitive therapy" in order to identify relevant articles published during the years of 2011 to 2016. No language limits were used. Studies conducted within control group, reviews, editorials, were excluded. Data on efficacy, acceptability and tolerability were extracted by three authors independently. Disagreements were resolved in a consensus meeting or by another reviewer.
Results: A total of eight articles were eligible for inclusion. Two are randomized clinical trials (RCTs) and six are observational studies. The two RCTs included showed a greater efficacy of CBT compared to standard care on auditory hallucinations (AHs). Nevertheless, they considered different CBT models, particularly Treatment of Resistant Command Hallucinations and Cognitive Therapy for Command Hallucinations. As regards non RCT-studies, all papers included showed reduction on frequency and severity of AHs and distress related to them. However, the lack of content details within non-RCTs studies decreased their comparability. In terms of predictive variables, our findings show that negative symptoms at baseline appeared to be the strongest predictor of the treatment efficacy. Indeed, negative symptoms showed a significant negative correlation on outcome.
Conclusion: Although more conclusive studies are still needed, we found some preliminary evidence for the efficacy of CBT in the treatment of command hallucinations.
Keywords: Auditory hallucinations; Cognitive-behavior therapy; Distress; Functional impairment; Psychotic disorder; Schizophrenia; Treatment.