Funding for this research was provided by:
US National Institute of Mental Health (R03MH117493)
National Institute on Drug Abuse (R01DA038466)
Article History
First Online: 28 August 2019
Compliance with Ethical Standards
:
: The authors declare that they have no conflict 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. Approval from the Norwegian Regional Committees for Medical and Health Research Ethics (REC) was not needed as data were anonymous and this study is outside of activities that require approval from the Norwegian REC.
: Informed consent was obtained from all individual participants included in the study.