Funding for this research was provided by:
National Institute on Drug Abuse (DA037820)
Received: 21 July 2020
Accepted: 24 September 2020
First Online: 12 October 2020
Ethics approval and consent to participate
: Ethics approval for the study protocol was given by the University of California, San Francisco Institutional Review Board.
: Informed consent was given by all study participants. Consent for publication of their anonymized data was given by all participants.
: The authors declare that they have no competing interests.