Support for cognitive-behavioral therapy (CBT) for psychosis has accumulated, with several reviews and meta-analyses indicating its effectiveness for various intended outcomes in a broad variety of clinical settings. Most of these studies, however, have evaluated CBT provided to the subset of people with schizophrenia who continue to experience positive symptoms despite adequate treatment with antipsychotics. Despite several reviews and meta-analyses, a specific estimate of the effects of CBT for patients with medication-resistant positive symptoms, for whom CBT is frequently used in outpatient clinical settings, is lacking. This meta-analysis examined CBT’s effectiveness among outpatients with medication-resistant psychosis, both on completion of treatment and at follow-up.
Systematic searches (until May 2012) of the Cochrane Collaborative Register of Trials, MEDLINE, PsycINFO, and PubMed were conducted. Sixteen published articles describing 12 randomized controlled trials were used as source data for the meta-analysis. Effect sizes were estimated using the standardized mean difference corrected for bias, Hedges’ g, for positive and general symptoms.
The trials included a total of 639 individuals, 552 of whom completed the posttreatment assessment (dropout rate of 14%). Overall beneficial effects of CBT were found at posttreatment for positive symptoms (Hedges’ g=.47) and for general symptoms (Hedges’ g=.52). These effects were maintained at follow-up for both positive and general symptoms (Hedges’ g=.41 and .40, respectively).
For patients who continue to exhibit symptoms of psychosis despite adequate trials of medication, CBT for psychosis can confer beneficial effects above and beyond the effects of medication.