Received: 7 September 2019
Accepted: 29 April 2020
First Online: 15 May 2020
Ethics approval and consent to participate
: This research was approved by the Human Ethics Committee of Shandong Mental Health Center. All patients were provided with written, informed consent. Participation was voluntary, and participants could withdraw at any time during the study.
: Not applicable.
: The authors declare that they have no competing interests.