Funding for this research was provided by:
A common research grant from Formas, The Swedish Research Council for Health, Working Life and Welfare and The Swedish Research Council (259-2012-48)
Received: 8 February 2019
Accepted: 28 November 2019
First Online: 17 December 2019
Ethics approval and consent to participate
: The Regional Ethical Review Board in Stockholm approved the study (reference number: 2012/1904–31/1). Written informed consent for the adolescent’s and their own participation in the longitudinal study was obtained from legal guardians.
: Not applicable.
: The authors declare that they have no competing interests.