Mishina, Kaisa http://orcid.org/0000-0003-1489-1433
Tiiri, Elina http://orcid.org/0000-0003-0728-0810
Lempinen, Lotta http://orcid.org/0000-0002-4752-3197
Sillanmäki, Lauri http://orcid.org/0000-0001-8101-2852
Kronström, Kim http://orcid.org/0000-0001-9810-6396
Sourander, Andre http://orcid.org/0000-0003-0361-7244
Funding for this research was provided by:
Academy of Finland (288960)
Article History
Received: 6 December 2017
Accepted: 18 April 2018
First Online: 27 April 2018
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: The ethical standards from the 1964 Declaration of Helsinki and its later amendments were followed. The Ethical Committee at the Hospital District of Turku University Hospital (1998, 2008) and the Ethics Committee of the University of Turku (2014) approved the study design and permission was obtained from school authorities. Participation was voluntary for adolescents and their anonymity was ensured. The questionnaires were completed anonymously. Parental consent was obtained by informing them about the study and they had possibility to refuse adolescent not to participate in the study.