Funding for this research was provided by:
National Institutes of Health (DA40391, MH110259, DA046203)
Received: 7 August 2019
Accepted: 17 October 2019
First Online: 28 November 2019
Ethics approval and consent to participate
: All participants provided written informed consent, and the study was conducted in accordance with the UCLA Medical Institutional Review Board rules and regulations (IRB no. 10-001099).
: Not applicable.
: The authors declare that they have no competing interests.