Identifying Optimal Parameters for Neuroscience-Informed Interventions for Misophonia

BackgroundMisophonia is the inability to tolerate certain aversive, repetitive common sounds. MethodsUsing a within-subjects experimental design, twenty-nine participants with misophonia and thirty clinical controls with high emotion dysregulation received inhibitory neurostimulation (1Hz) over a personalized medial prefrontal cortex (mPFC) target functionally connected to the left insula; excitatory neurostimulation (10Hz) over a personalized dorsolateral PFC (dlPFC) target; and sham stimulation over either target. Stimulations were applied while participants were either listening or cognitively downregulating emotions associated with personalized aversive, misophonic, or neutral sounds. Subjective units of distress (SUDS) and psychophysiological measurements (skin conductance response[SCR] and level [SCL], and high-frequency heart rate variability [HF-HRV]) were collected. ResultsCompared to controls, participants with misophonia reported higher distress ({Delta}SUDS = 1.91-1.93, ps<.001) when listening to and when downregulating misophonic distress, although no psychophysiological differences were found. Both types of neurostimulation reduced distress significantly more than sham, with excitatory rTMS providing the most benefit (Cohens dSUDS= 0.53; dSCL= 0.14). Excitatory rTMS also enhanced the regulation of emotions associated with misophonic sounds in both groups when measured by SUDS (dcontrol= 1.28; dMisophonia= 0.94), and in the misophonia group alone when measured with SCL (d= 0.20). Both types of neurostimulation were well tolerated and feasible to administer. DiscussionClinical controls and misophonic participants were different in their self-report but not in psychophysiological measures of distress and regulations. Participants reported the lowest misophonic distress when engaging in cognitive restructuring enhanced with high-frequency neurostimulation, a finding that offers insight into the best path forward for misophonia interventions.