CBTp for people with treatment refractory schizophrenia on clozapine: a systematic review and meta-analysis

Cognitive behavioural therapy for psychosis (CBTp), an effective treatment for people with schizophrenia, may have a role in clozapine refractory schizophrenia. A systematic-review and meta-analysis on the impact of CBTp on psychotic symptoms in people on clozapine. We searched PubMed, Embase, PsycInfo, CINAHL and Cochrane for randomised control trials of CBTp as augmentation in people with treatment-refractory schizophrenia on clozapine and conducted pair-wise meta-analyses. Four studies met inclusion criteria. On pairwise meta-analyses, the primary outcome of total psychotic symptoms was not significantly altered by CBTp at either therapy endpoint or six to twelve months follow-up. Secondary outcomes showed that CBT improved positive symptoms at both therapy endpoint (SMD −0.33, 95%CI −0.50 to −0.16, p = 0.002, I2 = 0%) and six to twelve months follow-up (SMD −0.20, 95%CI −0.38 to −0.02, p = 0.03, I2 = 0%) though did not alter negative psychotic symptoms at either timepoint. CBTp may lead to small benefits for positive symptoms refractory to clozapine. Given the low risks associated with CBTp, and the limited alternative options for clozapine refractory schizophrenia, this approach should be considered in this population.