Funding for this research was provided by:
Deutsche Forschungsgemeinschaft (ZUK 63)
Received: 14 November 2019
Accepted: 13 March 2020
First Online: 7 April 2020
Ethics approval and consent to participate
: All study procedures were in accordance with the Declaration of Helsinki [CitationRef removed] and approved by the Ethics Committee of the Medical Faculty of the Eberhard-Karls-University and the University Clinic Tübingen (project number 557/2015B01). Both the adolescent and the parent or guardian gave their informed consent after the study was explained to them.
: Not applicable.
: The authors declare that they have no competing interests.