Do adjunctive art therapies reduce symptomatology in schizophrenia? A meta-analysis

Art therapies are advocated by national bodies, such as the United Kingdom's National Institute for Health and Care Excellence, to alleviate the negative symptoms associated with schizophrenia. The last decade has however, seen several new larger well-controlled trials published suggesting an update is timely.

To asses randomised controlled trials (RCT) of art therapies for reducing the symptoms of schizophrenia - particularly negative symptoms.

Searches of PubMed and Scopus were conducted until May 2019 for RCTs examining the impact of art therapies on psychosis (positive, negative and total) symptoms in people diagnosed with schizophrenia. Study quality was assessed using the Cochrane risk of bias tool. Random effects meta-analyses were used to derive overall effect sizes. Moderator analyses were conducted using both meta-regression and categorical comparisons.

We identified 133 articles, of which 9 RCTs involving 948 participants (475 assigned to art therapies and 473 controls) met our inclusion criteria. Using random effects models, we calculated pooled effect sizes (Hedges g) for end-of-trial symptomatic outcomes. Effect sizes both for total symptoms [g = -0.27, 95% confidence interval (CI) -0.60 to 0.05, k = 6] and for positive symptoms (g = -0.10, 95%CI -0.35 to 0.15, k = 6) were non-significant; however, we did find significant reduction of negative symptoms (g = -0.42, 95%CI -0.70 to -0.14, k = 9). Meta-regression revealed that negative symptom reduction was larger in trials with a greater proportion of women and in trials with younger patients. Crucially, the negative symptom reduction following art therapies was limited to lower quality trials and did not emerge in trials that used blind assessment of outcomes.

This review presents a comprehensive meta-analysis of art therapies in schizophrenia in terms of both studies included and participant numbers. We found that art therapies did not significantly reduce total or positive symptoms. A "small" therapeutic effect was found for negative symptoms, but we show that the effect is not present in blind trials and may be subject to publication bias.