| The purpose of this study was to systematically evaluate the effects of music therapy on symptoms of schizophrenia and other serious mental illnesses. The primary goals of the study were to (a) determine if effect size dispersion existed between-studies via tests of heterogeneity and (b) attempt to quantify and describe the dispersion through an analysis of identified study characteristics. In this study, 11 descriptive study characteristics were coded and analyzed as moderator variables to examine their influence on the effect of music therapy on psychiatric symptoms. Symptoms were divided into the three broad outcome categories of general symptoms, positive symptoms, and negative symptoms, each of which was meta-analyzed separately. Results of heterogeneity testing within groups yielded a homogenous group of positive symptom studies and suggested a minimal effect of music therapy on positive symptoms. Tests of heterogeneity and an examination of l -squared indices revealed substantial between-study dispersion within the general and negative symptom categories. Results of Q test comparisons between groups indicated a moderate to large effect of music therapy on general symptoms depending on treatment type, duration, chronicity, and measurement type and a small to large effect of music therapy on negative symptoms depending on provider of treatment. |
