Funding for this research was provided by:
National Institute on Drug Abuse (L40 DA042431, 1F32DA033742-01A1)
National Institute of General Medical Sciences (1P20GM121341-01)
Norwegian Agency for International Cooperation and Quality Enhancement in Higher Education (PNA-2014/10088, NNA-2016/10023)
Received: 20 March 2019
Accepted: 6 August 2019
First Online: 20 August 2019
Ethics approval and consent to participate
: Not applicable.
: The authors declare that they have competing interests.