Misophonia is a condition characterized by strong, aversive reactions to specific sounds produced by others, often manifesting as intense negative emotions like anger or rage in response to nearby noises. The present study aimed to evaluate the effectiveness of an mHealth app in reducing misophonia symptoms and related cognitions. In this study, 85 participants were randomly assigned to an immediate app use (iApp) or delayed app use (dApp) group and completed measures at baseline (T0), after 15 days of app use (T1 for iApp, T2 for dApp), and at 1-month follow-up (T3). Intention-to-treat analyses at T1 revealed significant interaction effects
compared with the dApp group, the iApp group exhibited lower misophonia symptoms on select measures (interaction effect sizes ranging from d = 0.06 to 0.52) as well as reductions in anger ruminations and anger-related metacognitions (interaction effect sizes of d = 0.47). Within-group analyses demonstrated substantial reductions in misophonia symptoms from baseline to follow-up (iApp: d = 0.62-1.51
dApp: d = 0.89-1.75) with similar decreases in anger-related outcomes (iApp: d = 0.89-0.92
dApp: d = 0.85-0.90). Mediation analyses, however, did not support an indirect effect of the intervention on misophonia symptoms via changes in rumination or anger-related metacognitions. mHealth applications show promise in alleviating misophonia symptoms and related cognitive processes. Further research is needed to elucidate the roles of anger rumination and metacognitions in misophonia.