Received: 27 April 2021
Accepted: 9 August 2021
First Online: 19 August 2021
: According to study procedures, written informed consent was obtained from adolescents and parents participating at T<sub>1</sub> and T<sub>2</sub>. Study approval was given by the Regional committee for Medical and Health Research Ethics of Central Norway (reference numbers CAP survey T<sub>1</sub>: 4.2008.1393, T<sub>2</sub>: 2011/1435/REK Midt, and present study using T<sub>1</sub> and T<sub>2</sub> data: 2017/589/REK Midt). The Norwegian Social Science Data Services, The Data Protection Official for Research, gave approval to compare the main reason for referral, age and sex between participants and non-participants at baseline (reference number CAP survey: 19976). The research performed in accordance with the ethical standards in the Declaration of Helsinki from 1964 and later amendments. We affirm that all methods were accomplished in agreement with relevant guidelines and regulations.
: Not applicable.
: The authors declare that they have no competing interest.