Checknita, David http://orcid.org/0000-0002-7005-2565
Tiihonen, Jari
Hodgins, Sheilagh
Nilsson, Kent W.
Funding for this research was provided by:
Forskningsrådet för Arbetsliv och Socialvetenskap
Mobilisering mot Narkotika
Stockholms Läns Landsting
Landstinget Västmanland
Karolinska Institutet Strategic Funding
Uppsala University
Article History
Received: 9 June 2021
Accepted: 6 August 2021
First Online: 23 August 2021
Declarations
:
: The authors report no biomedical financial interests or potential conflicts of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. All waves of data collection were approved by the Regional Ethical Review Board in Stockholm. At each wave of data collection, participants signed informed consents, except at baseline when consent for those under age 18 was given by their parents. At collection of saliva samples, all participants were 18 or older, and they specifically consented to providing saliva samples for DNA extraction. Confidentiality of all the information was guaranteed, and at each wave of data collection, participants received gift certificates as compensation for their time.