Call Us: 866.CNS.TRIAL | Mail:


Our experienced team of Investigators specialize in a multitude of
therapeutic areas and indications including, but not limited to:

Chronic pain

Ethnobridging studies

Gastrointestinal disorders

Human abuse liability


Neurological disorders


Respiratory disorders

Women’s health

CNS Principal Investigators

David P. Walling, Ph.D.

David P. Walling, Ph.D.

Dr. Walling serves as Chief Executive Officer and Principal Investigator for CNS. He has participated as a lead or co-investigator in more than 200 clinical studies, with many focusing on schizophrenia and schizoaffective disorder. Dr. Walling has authored numerous articles in leading scientific journals including the American Journal of Psychiatry, American Journal of Psychotherapy, and Journal of Nervous and Mental Disease.

Prior to co-founding CNS, Dr. Walling held the position of Vice President of Clinical Services at both Psychiatric Management Resources, a subsidiary of Universal Health Services, Inc. and Stadt Solutions Pharmacy Corporation. He also served as Assistant Professor and Research Scientist in Psychiatry and Behavioral Sciences at the University of Texas Medical Branch at Galveston.

Dr. Walling received his doctorate in Counseling Psychology from the University of Southern California. He earned a Master of Science degree in Counseling from California State University Fullerton and a Bachelor of Science degree in Counseling Psychology from California State University Long Beach.

Armen Goenjian, M.D., D.F.A.P.A., F.A.C.G.S

Armen Goenjian, M.D., D.F.A.P.A., F.A.C.G.S
Since co-founding CNS in 2000, Dr. Goenjian has served as both Chief Medical Officer and Principal Investigator. He is currently a Research Professor of Psychiatry at the David Geffen School of Medicine at UCLA. Dr Goenjian practices privately at Memorial Counseling Associates in Long Beach and holds the position of Senior Medical Director of Psychiatry at Pacific and Community Hospitals of Long Beach.

Dr. Goenjian has published extensively on post-traumatic stress disorder and depression in peer reviewed journals. He has more than 13 years experience conducting phase I-IV clinical trials specializing in bipolar disorder, depression, schizophrenia, and post-traumatic-stress disorder.

Dr. Goenjian received his Bachelors of Science degree at the American University of Beirut and Doctorate in Medicine at the University of Tennessee. He is a Diplomate of the American Board of Psychiatry and Neurology in Psychiatry and Diplomate of the American Board of Geriatrics.

Mark Leibowitz, M.D.

As Medical Director of Early Phase Research, Dr. Leibowitz oversees all early-phase studies conducted in CNS’ 25,000 square foot Phase I research facility in Long Beach, CA. Dr. Leibowitz brings a wealth of experience to CNS, including almost 30 years of practicing medicine and over 19 years of conducting clinical research. His expertise is in early-phase research including more than 200 Bioequivalence and 50 Healthy Normal First in Human (FIH) studies. Dr. Leibowitz has conducted trials across a variety of indications including Alzheimer’s disease, schizophrenia, depression, diabetes, ADHD and hypertension. He has also specialized in abuse liability, Asian bridging, maximum tolerated dose, and CSF collection studies.

Dr. Leibowitz received his medical degree from Albert Einstein School of Medicine in New York. He also holds a Bachelor of Arts in Biology from Hofstra University where he graduated Summa Cum Laude. He is board certified in Internal Medicine.

Nirav Patel, M.D.

Nirav Patel, M.D.
Dr. Nirav Patel has collaborated with CNS since 2008 as a Principal and Sub-Investigator focusing on Neurological studies. He has extensive phase I-IV research experience with neurological disorders such as migraines, Parkinson’s disease, Alzheimer’s disease, dementia, multiple sclerosis, post-stroke spasticity and diabetic neuropathy.

Dr. Patel is Board Certified from the American Board of Psychiatry and Neurology and the National Board of Medical Examiners Parts I & II. He is affiliated with the Los Angeles Society of Neurological Sciences, the Los Angeles County Medical Association and the American Academy of Neurology. Additionally, Dr. Patel serves as Medical Director of the Stroke Center at Los Alamitos Medical Center and is a part of the Clinical Faculty in the Department of Neurology at Harbor–UCLA Medical Center. He was the former Chief Resident in the Department of Neurology at Harbor-UCLA Medical Center and is a Private Practitioner at Southland Neurologic Associates.

Having received his Bachelors of Science in Biomedical Sciences at University of California, Riverside, Dr. Patel then attended the University of California at Los Angeles School of Medicine and went on to complete his residency at Harbor-UCLA Medical Center in Torrance.

Omid Omidvar, M.D.

Omid Omidvar, M.D.
Dr. Omid Omidvar has collaborated with CNS since 2008 as a Principal and Sub-Investigator. He is board-certified in Neurology and has contributed to more than 80 Neurological studies. Dr. Omidvar is a member of the American Academy of Neurology as well as the California Medical Association. He is affiliated with Los Alamitos Medical Center and has practiced privately at Southland Neurologic Associates in Long Beach, California for over 10 years.

Dr. Omidvar received his medical degree, Diplôme d’État de Docteur en Médicine from Faculte de Medecine de Rouen, France. After finishing his residency in Neurology at the Harbor-UCLA Medical Center, he later served as the department’s Chief Resident. Dr. Omidvar currently serves as an Assistant Clinical Professor at the David Geffen School of Medicine at UCLA and is the Co-Medical Director of the MemorialCare Rehabilitation Institute at Long Beach Memorial Hospital.

Steven Reynolds, D.O.

Steven Reynolds, D.O.
Dr. Reynolds has served as Principal Investigator at CNS since 2010. His specialty being trials in General Health indications including type 2 diabetes, diabetic neuropathy, asthma, irritable bowel syndrome, high cholesterol and Crohn’s disease. Dr. Reynolds has practiced Family Medicine since 1995 and is currently in private practice with Family Health Care of Long Beach. He maintains a position as Associate Professor at the University of Irvine College of Medicine and also acts as a Police Surgeon and Consultant for the City of Long Beach Police Department.

Dr. Reynolds obtained his medical degree at Midwestern University, Chicago College of Osteopathic Medicine and holds an undergraduate degree in Microbiology from San Diego State University. He is Board Certified with the American Board of Family Practice and is a member of the American College of Occupational and Environmental Medicine. Dr. Reynolds holds affiliations with Long Beach Memorial Medical Center, Miller Children’s Hospital and Memorial Women’s Hospital.

Back to Top