Depression is a prevalent, often chronic and disabling disease. Current psychosocial and antidepressant treatments result in similar response rates with mostly symptom reduction, but not complete remission. Poor treatment adherence complicates depression management and prevention of recurrent episodes. Therefore, new therapies must be developed urgently, that alone or combined with present treatments, can significantly improve therapy outcomes.

Depression is potentially associated with decreased heart rate variability (HRV). Based on our previous studies' results which demonstrated HRV increase following auditory stimulation, we developed two interventions based on specifically for depression treatment composed and arranged music and tested the efficacy in a waiting list and placebo controlled double-blind study with depressed outpatients.

Depression status was assessed at the beginning of T1 and T2 using the Hamilton Rating Scale for Depression (HAM-D), Beck Depression Inventory (BDI), Hospital Anxiety and Depression Scale (HADS-D) and by a composite (COMP) scale based on HAM-D, BDI and HADS-D z-scores. Changes in depressive symptoms between T1 and T2 (5 week period) were assessed based on COMP and on HAM-D, BDI and HADS-D scores alone. Compared to the control arm, a significant, positive effect in COMP was observed for MT1 at T2. Both MT1 and MT2 were associated with significant positive effects (HAM-D and HADS-D scores). MT2 resulted in positive effects on BDI scores. No significant change in any depression score was detected in the placebo arm. Treatment continuation was associated with an effect increase (mean HAM-D score reduction of 60%) after 10 to 15 weeks of treatment.