OBJECTIVE: High Amplitude Low Frequency-Music Impulse Stimulation (HALF-MIS) is a form of Vagus Nerve Stimulation (VNS). The aim of the study was to determine the feasibility, efficacy, and potential side effects of HALF-MIS, used as an add-on treatment for depression.

METHODS: This is an open randomized controlled pilot study. Patients with depressive disorder were randomly allocated to either a HALF-MIS group with eight add-on HALF-MIS sessions (over a period of 3-4 weeks) or a control group which received treatment as usual. Seated in a specially designed chair() embedded with a transducer, their central nervous system was stimulated through the abdomen, () using music and vibration. Hamilton rating was performed. Side effects were registered.

RESULTS: Eighteen patients were randomized to the add-on treatment and 20 patients to the control group. Both groups show in Hamilton Depression Rating Scale (HDRS)-17 and in HDRS-6, although the HALF-MIS group had a greater decline of symptoms. This was a significant difference in intergroup analysis (p = .011, CI 95% for the HALF-MIS group 3.0588-8.5327 and CI 95% for the control group 0.2384-3.0). The (HDRS)-6 difference was also significant (p = .020, CI 95% for the HALF-MIS group 1.5911-5.0487 and for the control group -0.297 to 1.7058). No side effects were observed.

CONCLUSIONS: High Amplitude Low Frequency-Music Impulse Stimulation treatment seems to give beneficial effect as an add-on treatment for depression. HALF-MIS appears to be a safe and effective add-on treatment for depression.