Article History
Received: 20 March 2019
Accepted: 17 May 2019
First Online: 3 June 2019
Compliance with Ethical Standards
:
: The authors declare that they have no conflict of interest.
: Ethical approval was obtained from the Regional Research Review Board in Gothenburg, Sweden, before each data collection wave (Nos. 362-13; 2013-09-25; 2014-05-20; 2015-09-02; 2017-07-25).
: Informed consent was obtained from all individual participants included in the study and their legal guardians.