Overture for growth hormone: Requiem for interleukin-6?

Background: Music has been used for therapeutic purposes since the beginning of cultural history. However, despite numerous descriptions of beneficial effects, the precise mechanisms by which music may improve human well-being remain unclear. Methods: We conducted a randomized study in ten critically ill patients to identify mechanisms of music-induced relaxation using a special selection of slow movements of Mozart's piano sonatas. These sonatas were analyzed for compositional elements of relaxation. We measured circulatory variables, brain electrical activity, serum levels of stress hormones and cytokines, requirements for sedative drugs, and level of sedation before and at the end of a 1-hr therapeutic session. Results: Compared with controls, we found that music application significantly reduced the amount of sedative drugs needed to achieve a comparable degree of sedation. Simultaneously, among those receiving the music intervention, plasma concentrations of growth hormone increased, whereas those of interleukin-6 and epinephrine decreased. The reduction in systemic stress hormone levels was associated with a significantly lower blood pressure and heart rate. Conclusion. Based on the effects of slow movements of Mozart's piano sonatas, we propose a neurohumoral pathway by which music might exert its sedative action. This model includes an interaction of the hypothalamic-pituitary axis with the adrenal medulla via mediators of the unspecific immune system.