Data collection
The experimental group participated in the group music therapy twice a week, 50 minutes per session for 7 weeks. The therapy was led by a team of professional music therapists and study re- searchers. The participation rate for the 7-week group music therapy was 85%. Both the experimental and control groups received standard care that was commonly provided by the clinical facilities including antipsychotic medication.
The pretest and posttest measures were conducted at the same time for both groups. A professional researcher from LAXTHA of Korea directly measured pretest and posttest EEG. Psychiatric nurse specialists measured the pretest and posttest MMSE through in- dividual interviews with patients. Considering the ethical aspects of the study, mental health educational materials were provided to the control group after completing the posttest. In addition, if the control group participants wanted, they were allowed to participate in a 3-week music activity that included listening and playing.