Postdoctoral Fellows

Brandy Henry, Ph.D.

Dr. Henry is a clinician scientist who uses her years of practice experience to inform her research which aims to improve the health of criminalized populations. Her unique combination of research and practice experience led to her appointment by the Governor of Massachusetts to the state’s Restrictive Housing Oversight Committee which oversees housing conditions in Massachusetts’ prisons and jails. Dr. Henry also serves on the board of directors of multiple grass roots non-profits which provide direct services to incarcerated and formerly incarcerated people. Her work in these roles acts to ground her research in the complexity of translating research to inform policy and practice.

Dr. Henry received her Doctorate in Social Policy (Behavioral Health track) in 2019, and her Master of Arts degree in Social Policy (Behavioral Health track) in 2017 from the Brandeis University Heller School for Social Policy and Management.  While at Brandeis, she was awarded a Brandeis University Heller School Doctoral Fellowship (2018-2019), a Harvard Kennedy School Rappaport Institute Public Policy Summer Fellowship (2016), and a Ruth L. Kirschstein Predoctoral Individual National Research Service Award from the National Institute on Alcohol Abuse and Alcoholism (2015-2018). Dr. Henry also received a Master of Social Welfare degree from the University of California Los Angeles (UCLA) in 2012, and is a Licensed Independent Clinical Social Worker (LICSW) in the state of Massachusetts.  She earned a Bachelor of Arts degree in the field of Psychology, with minors in Statistics and Biology at Boston University (2006).

Dr. Henry’s dissertation research documented social determinants of incarceration, with a focus on the role of trauma for incarcerated people with mental health, and substance use disorders. In this work she used a mixed methods approach which included collecting data via in depth interviews with currently incarcerated people, and big data analysis of a secondary data set using latent class analysis and structural equation modeling. She has also been involved with NIDA funded Juvenile Justice Translational Research on Interventions for Adolescents in the Legal System (JJ-TRIALS) studies. Her work on these studies has examined implementation of organizational supports for screening, assessment, and referral to substance use, mental health & HIV treatment in juvenile justice systems. Dr. Henry has also published in the areas of private prisons, Hepatitis C drug pricing, and drug courts.

At Columbia she will continue her research which examines health disparities related to trauma, mental health, and substance use disorders within criminalized populations.

Karli Hochstatter, Ph.D., MPH

Karli Hochstatter, PhD, MPH, is a Postdoctoral Research Fellow in the HIV, Substance Abuse, and Criminal Justice T32 Fellowship Program at Columbia University’s School of Social Work. Dr. Hochstatter’s research focuses on preventing HIV and hepatitis C virus transmission and improving screening and treatment uptake among populations disproportionally burdened by substance use disorders, with a special focus on people who inject drugs and criminal justice-involved adults.

Dr. Hochstatter completed her PhD in Population Health Sciences with a minor in Criminal Justice Health (2019), Master of Public Health (2015), and Bachelor of Science (2013) degrees at the University of Wisconsin School of Medicine and Public Health. While at UW-Madison, she also served as an assistant for the UW Cooperative Extension Opioid Task Force, disseminating evidence-based opioid overdose prevention interventions to community coalitions across Wisconsin. Dr. Hochstatter is also a scholar in the Criminal Justice Research Training Program on Substance Use, HIV, and Comorbidities at Brown University.

Dr. Hochstatter has worked on several NIDA-funded research projects that address the intersecting epidemics of injection drug use and infectious diseases, particularly hepatitis C virus and HIV. Her dissertation research focused on using mobile health technology to improve hepatitis C and HIV-related outcomes and reduce opioid overdose death among people with opioid use disorder, as well as computer-tailored risk-reduction interventions that improve the health of people who inject drugs when implemented in harm reduction settings. She also served as project manager for a longitudinal cohort study of HIV-positive persons transitioning from prison to community-based care. In addition to this work, Dr. Hochstatter is currently working on using Global Hepatitis Outbreak Surveillance Technology, a tool recently developed by the CDC, to characterize hepatitis C transmission clusters among social networks of people who inject drugs and incarcerated person.

While at Columbia, Dr. Hochstatter will continue to develop, implement, and disseminate innovative strategies to prevent the transmission of HIV and hepatitis C virus among people with substance use disorders.

Melissa Slavin, Ph.D.

Dr. Slavin received her Doctorate of Philosophy (2019) and Master of Arts (2017) in Clinical Psychology from the University at Albany.  She completed her predoctoral internship at the Veterans Affairs Connecticut Healthcare System in West Haven.  Prior to this, she received her Bachelor of Arts in Psychology with a minor in Criminal Justice from the University of Connecticut.  Dr. Slavin is passionate about advocating for drug policy reform that reduces overcriminalization of non-violent offenses.  Her research has focused on identifying intrapersonal (e.g., cognitive expectancies, motivational states, personality traits) and interpersonal (e.g., sexual abuse, physical violence) factors associated with substance misuse and addictive behaviors, including problematic gambling and compulsive sexual behavior.  She intends for her research to inform prevention measures and harm reduction interventions that can be used as alternatives to incarceration. Her dissertation examined the effects of harsh restrictions on “psychological reactance”, a motivational state characterized by negative affect and cognition that may influence individuals’ substance use.  Dr. Slavin would like to continue research on personal and environmental risk and protective factors for addiction, particularly among justice-involved individuals.


Kristi Stringer, Ph.D.

Dr. Stringer received her Doctorate in Medical Sociology (2017) and her Master of Arts degree in Sociology (2012) from the University of Alabama at Birmingham (UAB). She earned her Bachelor of Science in the field of Psychology at Middle Tennessee State University in 2009. During her tenure at UAB, Dr. Stringer was an AHRQ pre-doctoral fellow at the Center for Outcomes and Effectiveness Research and Education in UAB’s Division of Preventive Medicine and was awarded a Ruth L. Kirschstein NRSA Individual Predoctoral Fellowship (F31) from the National Institute of Drug Abuse in 2014. Dr. Stringer’s research agenda focuses on the impact of health related stigmas on the HIV treatment cascade and the development of stigma reduction interventions aimed at increasing HIV prevention and treatment adherence behaviors. Her dissertation research utilized a mixed-methods approach to understand the adverse effects of substance use stigma and HIV-related stigma on adherence to antiretroviral medications and retention in HIV care among drug involved people living with HIV (PLWH). During her post-doctoral training at Columbia University, Dr. Stringer plans to adapt a stigma reduction intervention to address health related stigmas experienced within healthcare environments among drug involved PLWH in Kazakhstan through Columbia’s collaboration with the Global Health Research Center of Central Asia (GHRCCA).

Predoctoral Fellows

Christina Aivadyan

Christina received her Master of Science degree in Social Work from Columbia University in 2013 and Bachelor of Arts degree in Psychology from New York University in 2007. As a Project Director at the New York State Psychiatric Institute, she has over 11 years of genetic, clinical, and epidemiological research experience focused on substance use and co-occurring psychiatric disorders. Additionally, Christina contributed to the development of a motivational interviewing-based brief technological intervention for alcohol and marijuana use and sexual risk behaviors among homeless young adults in a clinical trial in the Columbia University Department of Psychiatry. Christina’s research interests include substance use and HIV prevention and intervention, particularly among young adults with a history of trauma.



Ariel Marie Shirley Richer

Ariel Richer is a doctoral student at the Columbia University School of Social Work working within the Social Intervention Group (SIG). Her focus is on intimate partner violence prevention, community-based participatory research, and working collaboratively with Indigenous and Native communities. She works under the direction of Associate Professor Louisa Gilbert on project E-WORTH and project WINGS.

Previously, she worked as an Impact Evaluator at the Administration for Native Americans where she worked directly with community-based organizations developing logic models, evaluation plans, data collection tools, and processes at a community-specific level and across a diverse set of communities. She is fiercely committed to addressing gender-based issues at large, especially gender-based violence, and has over seven years of experience within domestic violence organizations, sexual assault resource centers, and economic enhancement programs for survivors of trafficking and domestic violence. Ariel is the co-founder of the Indigenous- and womxn-led coalition, Rising Hearts. She earned her Master of Science in Social Work, Social Enterprise Administration from Columbia University School of Social work in 2015 and is a Licensed Master Social Worker.


Former Fellows