1 Medical Scientist Training Program, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA. Electronic address: davetzhu@gmail.com.
2 Medical Scientist Training Program, University of California Los Angeles, Los Angeles, CA, USA.
3 School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
4 HIV Center for Clinical and Behavioral Studies, Department of Psychiatry, Columbia University, New York City, NY, USA.
5 Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA; Program Evaluation Resource Center, Office of Mental Health and Suicide Prevention, Department of Veterans Affairs, Menlo Park, CA, USA.