Nehal P. Vadhan, PhD

Assistant Professor, Center for Psychiatric Neuroscience, The Feinstein Institute for Medical Research

Associate Professor, Departments of Psychiatry and Molecular Medicine, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell

Phone: (516) 837-1685

About the Investigator

Dr. Vadhan received his PhD in Clinical Psychology from Hofstra University in 2003, working on studies of neuropsychological functioning in psychotic and comorbid substance use disorders. He then did a 2-year postdoctoral fellowship at the New York State Psychiatric Institute (NYSPI) at Columbia University Medical Center (CUMC), receiving training in laboratory and clinical research in the Division on Substance Abuse under Drs. Richard Foltin, Carl Hart and Frances Levin.

Dr. Vadhan stayed on at NYSPI/CUMC as an assistant professor of Clinical Psychology in Psychiatry, where he completed studies of the neuropsychiatric effects of substance use, in individuals with and without psychiatric illness. These studies were supported by grants from the National Institute on Drug Abuse (NIDA) and the Brain and Behavior Research Foundation (BBRF), and he received the prestigious Irving Scholars Award from CUMC College of Physicians and Surgeons in 2010. He moved to Stony Brook School of Medicine in 2014, and joined Northwell Health in 2017. He is an investigator and project director in the Center for Addiction Services and Personalized Interventions (CASPIR) at the Feinstein Institute for Medical Research, headed by Dr. Jon Morgenstern. He is also developing the Human Neuropsychopharmacology Laboratory (HNPP) at the Feinstein Institute, to study the acute neuropsychiatric effects of substances such as marijuana, alcohol and stimulants.

He is the author or co-author of 24 peer-reviewed publications and 3 book chapters/ reference volume entries. His research has been recognized by the Society for Biological Psychiatry, the International Neuropsychological Society and the American Psychological Association. Dr. Vadhan has also mentored many post-bac, graduate and postdoctoral students in research, taught at the university level and is a clinical practitioner/supervisor.

Research Focus

Cognitive and motivational sequelae of substance use

The potential effects of drugs of abuse on cognitive and psychiatric functioning are of significant clinical and public concern, but consensus on these effects is lacking. This is due in part to the minimal level of translation between the major paradigms used to assess such effects: cognitive neuroscience, behavior pharmacology, and longitudinal observation. Thus, Dr. Vadhan and colleagues employ a laboratory model that integrates these approaches. Completed or planned research projects based on this model include studies of: 1) learning, attention, executive and reward functions; 2) the acute effects of substance such as marijuana, stimulants and depressants on these and related functions, 3) the neural correlates of these functions, and 4) the relationship of these phenomena to behavior change and clinical treatment outcome, in substance users. The end goal of results from these studies is to inform the interaction between substance use and psychiatric illness, and spur treatment development for both.

Psychological interventions for substance use disorders

Since coming to CASPIR/Feinstein, Dr. Vadhan has been directing a clinical trial of brief, adaptive and telehealth-enabled psychological interventions for problem drinking (PI: Morgenstern) that employs a combination of traditional and ecological measurement of outcome. He is also collaborating with CUMC investigators on a study involving neural and mobile assessment of behavior change in problem drinkers.


Columbia University Medical Center & NYS Psychiatric Institute
Degree: Postdoctoral Fellowship
Field of Study: Substance Abuse Research

Hofstra University
Degree: PhD
Field of Study: Clinical and School Psychology

Zucker Hillside Hospital
Degree: Internship
Field of Study: Clinical Psychology

West Islip High School
Degree: Internship
Field of Study: School Psychology

Hofstra University
Degree: MA
Field of Study: Clinical and School Psychology

Binghamton University
Degree: BA
Field of Study: Psychology

Awards & Honors

2012 Top Poster Award Finalist, Probabilistic category learning is associated with dopamine D2 receptor availability in the ventral striatum of cocaine users, Society of Biological Psychiatry
2010 Irving Scholars Award, Decision-making and reward sensitivity in cocaine abusers: relationship to cocaine-taking in the laboratory, Irving Institute for Clinical and Translational Research, Columbia University Medical Center
2008 NARSAD Young Investigator Award, Acute subjective and neurocognitive effects of smoked marijuana in prodromal psychosis, Brain and Behavior Research Foundation
2002 Dissertation Research Award, Social self-efficacy in the schizophrenia spectrum, American Psychological Association

  1. Vadhan, N.P., Corcoran, C.M., Bedi, G., Keilp, J.G., & Haney, M. (2017). “Acute effects of smoked marijuana in marijuana smokers at clinical high-risk for psychosis: A preliminary study.” Psychiatry Research, 257, 372-374.
  2. van de Giessen, E., Weinstein, J., Cassidy, C., Dong, Z., Ghazzoui, R., Kegels, L., Xu, X., Haney, M., Vadhan, N.P., Slifstein, M., & Abi-Dargham, A. (2016). “Blunted striatal dopamine release in the striatum of cannabis dependent participants.” Molecular Psychiatry, 22, 68-75.
  3. Jones, J.D., Vadhan, N.P., Luba, R.R., & Comer, S.D. (2016). “The effects of heroin administration and drug cues on impulsivity.” Journal of Clinical and Experimental Neuropsychology, 38(6), 709-720.
  4. Bedi, G., Shiffrin, L, Vadhan, N.P., Nunes, E.V., Foltin, R.W., & Bisaga A. (2016). “Effects of Levodopa Carbidopa-Entacapone and smoked cocaine on facial affect recognition in cocaine smokers.” Journal of Psychopharmacology, 30(4), 370-377.
  5. Carpenter, K.C., Bedi, G., & Vadhan, N.P. “Understanding and shifting drug-related decisions: contributions of automatic decision-making processes.” (2015). Current Psychiatry Reports, 17, 65, 1-11.
  6. Foltin, R.W., Haney, M., Rubin, E., Reed, S.C., Vadhan, N.P., Balter, R., & Evans, S.M. “Development of translational preclinical models in substance abuse: effects of cocaine administration on cocaine choice in humans and non-human primates.” (2015) Pharmacology, Biochemistry & Behavior, 134, 12–21.
  7. Gill, K.E., Poe, L., Azimov, N., Ben-David, S., Vadhan, N.P., Girgis, R., Moore H., Cressman, V., & Corcoran, C. “Reasons for cannabis use among youths at ultra high risk for psychosis.” (2015). Early Intervention in Psychiatry, 9(3), 207-210.
  8. *Benedict, E.S., Gorman, A., van Gorp, W.G., Foltin, R.W., & Vadhan, N.P. (2014). “Self-reported attention and mood symptoms in cocaine abusers: relationship to neurocognitive performance.” Psychiatry Research, 219(3), 598-603.
  9. Vadhan, N.P., Myers, C.E., Benedict, E.S., Rubin, E.R., Foltin, R.W., & Gluck, M.A. (2014). “A decrement in probabilistic category learning in cocaine users after controlling for marijuana and alcohol use.” Experimental and Clinical Psychopharmacology, 22(1), 65-74.
  10. *Roebke, P.V., Vadhan, N.P., Brooks, D.J., & Levin, F.R. (2014). “Verbal learning in marijuana users seeking treatment: a comparison between depressed and non-depressed samples.” American Journal of Drug and Alcohol Abuse, 40(4), 274-279.

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