Several music research studies which involved music therapy, Chinese five-element music, singing, choral singing, music listening, vocal and singing exercises, personalized and group music therapy have demonstrated significant findings in treatment of depression and depressive symptoms. Music was found to increase the independence feeling, self-confidence; lead to cope with feelings, such as helplessness and depression; induce alpha waves; trigger the endorphin release. Music was found to trigger deep emotion, evoke past rejoiceful moments, and interpersonal relationships including autonomy and taking responsibility. Singing may facilitate a relaxation response that increases vocal fold flexibility, enabling one to express more emotional dynamics through his /her own voice.

Proposed Mechanisms of Change

The studies reviewed suggest that shifts in depressive symptoms resulting from engagement in music and music therapy are a result of mechanisms of change across several domains:

Physical: neurophysiological and neurochemical effects, such as endorphin release, stimulation of cognitive functioning i.e., reminiscence and activation of amygdala, hippocampus, and nucleus accumbens;
Cultural (creative/aesthetic): processing of music stimuli in rhythm and pitch, musical experience including movement, physiological functioning, and imitating of musical rhythm;
Intrapersonal: improvement of well-being, activation of remaining capabilities, self-efficacy, validation, increase of autonomy, and self-confidence developed through experiences of success;
Social: improvement of interaction skills and relational abilities, to trigger interpersonal relationships, to stimulate social participation.
The interventions for depression through music were most effective because of trained music therapists rather than engaging with musical professionals. Effective music interventions were diverse and included receptive music therapy and music listening, mixed intervention types, instrumental play and improvisation, and individualized, individual preferred music or reminiscence in music listening or singing.



https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6331422/pdf/fpsyg-09-02655.pdf