Music exposure reduces anxiety- and depression-like behavior in rodents: a systematic review and multilevel meta-analysis

Music exposure may alter affect-related behavior in rodents, but findings vary among studies and little is known about effects on behavioral variability. We conducted a preregistered systematic review and multilevel meta-analysis of 20 experimental studies (298 effect sizes) of music exposure in laboratory rodents. We quantified changes in average anxiety- and depression-like behavior using the log response ratio (lnRR) and changes in between-animal variability using the log variability ratio (lnVR), while accounting for non-independence among effects. We also assessed reporting, methodological quality, and risk of bias using CRIME-Q. Music exposure was associated with about a 20% reduction in anxiety- and depression-like behavior relative to controls, but no overall change in behavioral variability. Average responses differed among behavioral assays, while exploratory analyses of variability suggested context-dependent effects: anxiety-like outcomes tended toward greater variability and depression-like outcomes toward lower variability, and behavioral assay and music meta-genre explained comparatively larger shares of heterogeneity in lnVR. Reporting of sample-size justification, allocation, blinding, attrition, and acoustic delivery was often incomplete in the primary studies. Evidence was limited to 20 studies and predominantly to young adult rodents and short-term exposures, constraining inference about variability and generalization beyond the laboratory contexts studied.