Effects of binaural beats on acute stress recovery and autonomic regulation in multiple sclerosis: a pilot double-blind randomized controlled trial

BACKGROUND: Stress dysregulation is a hallmark of multiple sclerosis (MS), linked to impaired HPA axis responsiveness and autonomic recovery. Binaural beats (BBs) are a safe, non-invasive method for stress modulation, but their efficacy in MS is unclear. METHODS: Sixty participants (30 people with MS (PwMS) and 30 matched healthy controls (HCs)) were randomized to BBs or sham groups in a double-blind design. Stress was induced using the Trier Social Stress Test (TSST), a standardized protocol involving public speaking and mental arithmetic tasks. Salivary cortisol (SC), heart rate variability (HRV), and electroencephalography (EEG) were measured at pre-stress, post-stress, and post-stimulation. The BBs condition involved 240 Hz tones in the right ear and 244 Hz tones in the left ear for 20 min, while the sham condition used identical 244 Hz tones in both ears. RESULTS: Salivary cortisol increased significantly after the TSST in HCs but not in PwMS, indicating blunted HPA reactivity in MS. Exposure to BBs led to significant reductions in SC in both PwMS and HCs, unlike the sham condition. HRV analysis showed reduced power in the high-frequency band (PHF) and increased power in the low-frequency (PLF) and very low-frequency (PVLF) bands after BBs. EEG findings further supported these results, showing stress-related increases in signal complexity after stress induction and a trend toward normalization following BBs. CONCLUSION: In this pilot trial, binaural beats were associated with reduced salivary cortisol and significant changes in HRV and EEG indices post-stress in both PwMS and healthy controls, indicating measurable physiological responses to the intervention.