Funding for this research was provided by:
National Institutes of Health (P01 DA012408)
National Institutes of Health (R01 DA041510)
National Institutes of Health (U54 GM087519)
Article History
Received: 9 January 2018
Accepted: 5 February 2018
First Online: 14 March 2018
Ethics approval and consent to participate
: Not applicable.
: Not applicable.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.