Dear Editor,
Several studies have demonstrated that music can alter blood pressure parameters as well as induce a state of relaxation in patients in clinical settings. As, the underlying neurochemical changes present in music listeners are currently not well-understood, the authors set up an experimental study to explore differences in blood plasma signalizing molecules in pre and post music listening groups when compared with controls. They found that music listening seems to promote a drop in IL-6 level and in the plasma morphine level, associated with initial vasodilatation and an increase in peripheral mononuclear opiate receptor expression as a compensatory response. All of these lead to a relaxing effect via central and peripheral nervous system processes. Although this study represents an important and relevant addition to the literature on the subject, some points need to be clarified. First of all, the criteria for excluding subjects could be enumerated, such as, intake of medicine like psychotropic drugs, evaluation of anxiety disorders before starting the experiment, as well as a pregnancy test. The sample size is also small consisting of volunteers who could differ in several ways from nonvolunteers. Another question is whether the subjects knew the hypothesis before the experiment and if it was a double blind. It would be useful to have information on these points.
Sincerely,
Giovanni Marcos Lovisi1,
Heloise Siqueira2,
Patricia Matu3
1 Federal University Rio de Janeiro State Medical School, e-mail: [email protected]
2 Federal University Mato Grosso Medical School
3 Medical student in the Federal University Rio de Janeiro State Medical School
Received: 2004.08.10

Keywords: Cytokines - metabolism, Double-Blind Method, Music, Music Therapy, Narcotics - metabolism, Relaxation, Reproducibility of Results