Treating Depressive Symptoms in Psychosis: A Network Meta-Analysis on the Effects of Non-Verbal Therapies

Aims: The aim of this study was to examine whether non-verbal therapies are effective in treating depressive symptoms in psychotic disorders. Material and Methods: A systematic literature search was performed in PubMed, Psychinfo, Picarta, Embase and ISI Web of Science, up to January 2015. Randomized controlled trials (RCTs) comparing a non-verbal intervention to a control condition in patients with psychotic disorders, whilst measuring depressive symptoms as a primary or secondary outcome, were included. The quality of studies was assessed using the ‘Clinical Trials Assessment Measure for psychological treatments’ (CTAM) scale. Cohen’s d was calculated as a measure of effect size. Using a Network Meta-analysis, both direct and indirect evidence was investigated. Results: 10 RCTs were included, of which three were of high quality according to the CTAM. The direct evidence demonstrated a significant effect on the reduction in depressive symptoms relative to treatment as usual (TAU), in favor of overall non-verbal therapy (ES: -0.66, 95% C.I. = -0.88, -0.44) and music therapy (ES: -0.59, 95% C.I. = -0.85, -0.33). Combining both direct and indirect evidence, yoga therapy (ES: -0.79, 95% C.I. = -1.24, -0.35) had a significant effect on depressive symptoms, and occupational therapy (ES: 1.81, 95% C.I. = 0.81, 2.81) was less effective, relative to TAU. Exercise therapy did not show a significant effect on depressive symptoms in comparison to TAU (ES: -0.02 95% C.I. = -0.67, 0.62). Due to inconsistency of study evidence, the indirect effects should be interpreted cautiously. Conclusions: Non-verbal therapies appear to be effective in reducing depressive symptomatology in psychotic disorders, in particular music therapy and yoga therapy.