Marina Bussel, M.D.

Medical Director of ProScience Research Group is a Board Certified Psychiatrist and has been active in clinical trials since 2004.  Dr. Bussel has served as a Principal Investigator in over 100 trials and as a Sub-Investigator in over 60 trials in a variety of CNS areas including Schizophrenia, Major Depression Disorder, Bipolar Disorder, Attention Deficit Hyperactivity Disorder, Anxiety Disorder, Insomnia, and Migraine.  She completed her Psychiatry Residency Training and the Child and Adolescent Psychiatry Fellowship Programs at the Cedars-Sinai Medical Center affiliated with the UCLA School of Medicine in Los Angeles, California.  Dr. Bussel then went on to complete the Public Psychiatry Fellowship of New York Psychiatric Institute at the Columbia University Medical Center.
Dr. Bussel is known for her proactive and thorough medical oversight on the appropriate selection of participants as well as ensuring that all safeguards are in place for a safe and successful trial. She is also extensively involved in the integrity and management of all study data as well as recruitment strategies  


Arthur Kopp, M.D.

Research Physician and CEO of ProScience Research Group is Board Certified in Psychiatry and has over 11 years of experience in research and over 20 years in Psychiatry.  He completed the Psychiatry Residency Training Program at Maimonides Medical Center in Brooklyn, NY. He went on to complete the Addiction Medicine Fellowship at Loma Linda University Medical Center wherehe gained experience as a Research Physician in successful completion and recruitment of Phase II through Phase IV clinical trials specializing in Depression and Schizophrenia. In addition to his role as an investigator, Dr. Kopp treats patients at Gateways Hospital and Mental Health Center where he also serves on the Quality Assurance Committee. Dr. Kopp also has an extensive private practice composed of Los Angeles County patients.

Dr. Kopp is known for his thorough medical oversight on the appropriate selection and recruitment of participants. He is largely responsible for the patient care and oversight at our inpatient facilities and is a certified rater for numerous studies.  Dr. Kopp is well-known for his strong rapport and commitment to his patients.


Larry Ereshefsky, Pharm.D., FVVP, BCPP

Dr. Ereshefsky has joined ProScience Research Group (PSRG) as an investigator and as their lead Consultant.  Dr. Ereshefsky is extensively involved in staff training and works to ensure that PSRG maintains a culture of excellence.  He has assisted in developing processes and procedures that improve the overall quality of psychiatric and neurologic clinical research conducted at PSRG’s Los Angeles outpatient and inpatient facilities.  He applies his 40-year successful track record in drug development as a Principal Investigator and clinical psychopharmacologist to guide the growth and performance of our operations.  Among his contributions to the literature are studies evaluating the ‘placebo response’ observed in clinical trials and how to improve signal detection.  He has also been an investigator on NIMH grants, which have focused on the characteristics and time course of patient partial and non-adherence to prescribed and research therapies.  Strategies to improve adherence with therapy, including research protocols at PSRG benefit from his experience and insights.  One of the keys to success in clinical research is the enrollment of appropriate patients into studies; we recognize that an inappropriate patient randomized into clinical protocol can jeopardize signal detection and safety. 

Dr. Ereshefsky, remains a consultant for many Pharmaceutical companies guiding clinical drug development plans and the application of translational science to de-risk Proof of Concept.  He is currently the Chief Scientific Officer of Follow the Molecule: CNS Consulting LLC. He was formerly VP and Global Leader for Early Phase CNS, and Therapeutic area leader at PAREXEL International for 13 years (including time as the Chief Scientific Officer and Executive VP of California Clinical trials). He is a retired Regent’s Professor and Program Director for Clinical Psychopharmacology, holding an endowed chair in Psychiatric Pharmacy at The University of Texas at Austin.  He is also a retired Clinical Professor of Psychiatry and Professor of Pharmacology at The University of Texas Health Science Center in San Antonio (1977-2003). Dr. Ereshefsky received his Pharm.D. and advanced practice residency in psychiatric pharmacy from the University of Southern California – Los Angeles County Medical Center (1972-1977). He is board-certified in Psychiatric Pharmacy.


Hannah Lark, B.S, M.S.

Clinical Director at ProScience Research Group has over four years of clinical research experience and has conducted over 25 clinical research studies in a variety of CNS areas.  Hannah has worked as a Clinical Research Coordinator and Rater at ProScience Research Group since 2014.  She received her Bachelor of Science in Biology at the University of Wisconsin and her Master of Science in Exercise Physiology at the University of Kentucky in 2014.
Hannah has volunteered her time in an Emergency Department, Children’s Hospital, and Research Laboratories, giving her a wide array of experience in research and patient care.  She is known for her quality assurance of clinical data, attention to detail, and adherence to protocol.  

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Karla Nieto, B.A.

Clinical Regulatory Specialist at ProScience Research Group has experience working in clinical settings since 2018.  Karla has conducted over 10 different clinical research studies in a wide range of CNS areas.   She has her Bachelor of Arts in Molecular & Cell Biology from the University of California, Berkeley. Karla is known for her quality assurance of clinical data, preparing and reviewing regulatory documents and her attention to detail. 

Hannah Bojorquez, B.A.

Clinical Research Coordinator at ProScience Research Group has experience conducting over 10 different clinical research studies in a wide range of CNS areas.  Hannah has experience working clinical settings since 2018.  She has her Bachelor of Art in Psychology from California State University Fullerton.  Hannah is known for her skilled collection and processing of laboratory samples, accuracy of vital signs, and ECG data.