Published online Dec 19, 2019. doi: 10.5498/wjp.v9.i8.107
Peer-review started: June 4, 2019
First decision: August 2, 2019
Revised: September 3, 2019
Accepted: October 14, 2019
Article in press: October 14, 2019
Published online: December 19, 2019
Art therapies are advocated by national bodies, such as the United Kingdom’s National Institute for Health and Care Excellence, particularly to alleviate the negative symptoms associated with schizophrenia. The last meta-analysis is now a decade old and several new larger well-controlled trials have been recently published. A meta-analytic update is timely.
The present study aimed to assess randomised controlled trials (RCT) of art therapies for reducing the symptoms of schizophrenia – particularly negative symptoms.
A key objective is to evaluate and update evidence for future guidelines concerning treatment suggestions.
A search of PubMed and Scopus was conducted until May 2019 for RCTs assessing symptomatic outcomes following art therapy. Study quality was assessed using the Cochrane risk of bias tool. Random effects meta-analyses were conducted using Comprehensive Meta-Analysis (version 2). 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 therapy 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 were non-significant for total symptoms [g = -0.27, 95% confidence interval (CI) -0.60 to 0.05, k = 6] and positive symptoms (g = -0.10, 95%CI -0.35 to 0.15, k = 6); however, we did find significant negative symptom reduction (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 did not, however, 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. The findings have implications for clinical practice and future treatment guidelines (e.g., National Institute of Clinical Excellence) that have previously recommended using art therapies to alleviate negative symptoms in people with schizophrenia.
The current meta-analysis suggests that RCTs of art therapies do not provide evidence of any reduction in total, positive or indeed, negative symptoms. The latter is important as this has been viewed as a key aspect of art therapies in schizophrenia – being recommended in influential national guidelines such as that by National Institute of Clinical Excellence. Future trials might investigate whether one particular form of art therapy offers more benefit than others. They might also look at whether younger individuals and women do benefit more than men.