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Founded in 2000, CNS has grown to become one of the largest clinical research providers in the country, and the largest in Southern California. CNS operates three outpatient clinics located in Southern California (Garden Grove, Long Beach and Torrance). Additionally, CNS’s Long Beach facility offers a dedicated Phase I Unit.
Center Leadership

David Walling, Ph.D.
Chief Clinical Officer
Dr. Walling co-founded Collaborative Neuroscience Research (CNS) in 2000 to advance medical knowledge through the execution of clinical trials. His operational and strategic leadership has enabled the growth of CNS into one of the largest clinical research providers in the US. He is a principal investigator for many studies at the inpatient unit in Long Beach as well as the outpatient clinic in Garden Grove. Dr. Walling advises pharmaceutical companies in numerous ways including the creation of drug development plans, design and analysis of clinical trials in all phases, and preparation for interactions with regulatory agencies.
Work History
Dr. Walling has served as an investigator in over 600 trials, including over 100 Phase I trials, with many focusing on schizophrenia and cognition, areas in which he is recognized as a thought leader.
Before founding CNS, Dr. Walling was VP of Clinical Services at Psychiatric Management Resources & Stadt Solutions Pharmacy Corporation. He has also served as an Assistant Professor and Research Scientist in Psychiatry and Behavioral Sciences at the University of Texas Medical Branch at Galveston. Dr. Walling has clinical experience as a licensed psychologist and marriage, family, and child counselor.
Dr. Walling has authored dozens of articles on psychiatric indications that have been published in leading scientific journals. Dr. Walling also provides training to rater training companies for some of the most widely used psychiatric and cognitive rating scales including the Positive and Negative Syndrome Scale (PANSS).
Dr. Walling is a highly sought-after KOL in psychiatry and in digital device and software technologies. His pioneering work in small proof of concept studies within Phase I development programs has ensured the successful path for several drugs. He holds multiple advisory board memberships and consulting positions for sponsors.
Education
Dr. Walling received his doctorate in Counseling Psychology from the University of Southern California. He attended California State University, Long Beach, earning a master’s degree in Counseling as well as a bachelor’s degree in Psychology.

Dalia Botros, MD, MBBS
Chief Operating Officer
Dr. Botros joined CNS in 2008, bringing in over 10 years’ experience in clinical research. She leads operations for all CNS’s locations, ensuring policies and procedures are optimized and continuously reviewed to exceed the highest standards of industry expectations. Dr. Botros works relentlessly to achieve effective project planning and operational management for each trial. She makes sure that clinical research activities are fully compliant with federal regulations and ICH/GCP guidelines.
Work History
Prior to being elevated to her current role in 2020, Dr. Botros served as Director of Operations for the CNS Long Beach site for 10 years. She led the CNS Clinical Pharmacology Unit expansion to support both healthy normal volunteers and patient populations in early phase clinical trials and developed the associated standard operating procedures. From 2008 to 2010, Dr. Botros was Site Director for CNS’s Torrance site, managing the day-to-day operations of the research clinic and supervising the clinical team. Prior to joining CNS, Dr. Botros worked in Dermatology Research as a Clinical Research Fellow, completing almost 50 studies for over 20 pharmaceutical companies. Earlier on, she was a General Physician at the Alexandria Medical University Hospital as well as an obstetrician/Gynecologist at the Kafr Dawar Public Hospital in Alexandria, Egypt. Dr. Botros has published numerous clinical studies and poster presentations and has been a guest speaker for a variety of pharmaceutical companies.
Education
Dr. Botros received her medical degree from the Alexandria University School of Medicine in Egypt. She is fluent in English, French and Arabic.
Core Clinical Team

Armen Goenjian, MD, LDFAPA, FACGS
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Dr. Goenjian has been in his current role with CNS since he co-founded the organization in 2000. He serves as a principal investigator for studies at the Torrance location. His responsibilities include providing scientific and strategic guidance to clients and internal project groups with emphasis on medical issues, support for protocol development, therapeutic area training, and coordination of medical monitoring activities. He provides medical and clinical research support for aspects of early drug development including conducting hospital rounds for inpatient studies.
Work History
Dr. Goenjian has completed over 300 trials as an investigator, primarily focusing on psychiatric indications including ADHD, anxiety, bipolar disorder, depression, PTSD, and schizophrenia. Dr. Goenjian is a Research Professor of Psychiatry at the David Geffen School of Medicine at UCLA as well as the Senior Medical Director for Memorial Counseling Associates. Additionally, he 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 been the primary investigator of multiple post-disaster studies, including in Armenia, Greece, and Nicaragua. He has been the recipient of various awards for his research and humanitarian work related to natural disasters including FEMA, the American Psychiatric Association, the Greek Government, and the President of Armenia.Dr. Goenjian has been a psychiatric consultant to the World Health Organization, UNICEF, and various governments, including Greece, Turkey, Taiwan, Honduras, and Nicaragua. He has published extensively in peer-reviewed journals, primarily on PTSD and depression. He is a is Lifetime Distinguished Fellow of the American Psychiatric Association.
Education
Dr. Goenjian is board certified in psychiatry. He received his Bachelor of Science at the American University of Beirut and Doctorate in Medicine at the University of Tennessee.

Haig Goenjian, M.D.
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Dr. Goenjian joined CNS in 2016 as a sub-investigator. Since 2018 he has been a principal investigator for trials at the Garden Grove location as well as a sub-investigator for trials at the Long Beach location. Dr. Goenjian has provided feedback for sponsor protocols and has been involved in the CNS Phase 1 Early Development Team.
Work History
Dr. Goenjian has served as an investigator in over 250 trials, including over 50 Phase I trials. His experience includes all major psychiatric indications as well as many trials in healthy subjects. He has investigated driving simulation and Asian bridging trials, complex trials involving imaging and electrophysiology, and has been on the frontier of trials investigating digital therapeutics, wearable technologies, and other devices. In addition to conducting clinical trials, Dr. Goenjian also is an inpatient attending at Ocean View psychiatric hospital and works in conjunction with community telepsychiatry programs. He is also a long-standing Councilor on the Board of SCPS, the Southern California branch of the American Psychiatric Association. He has participated in numerous volunteer activities, giving back to the community through humanitarian work. Dr. Goenjian has received numerous awards and published extensively in peer-reviewed journals.
Education
Dr. Goenjian is board certified with the American Board of Psychiatry and Neurology. He obtained his Medical Degree from Tulane University School of Medicine. Subsequently, he completed his General Psychiatry Residency at Harbor-UCLA Medical Center, serving as Chief Resident from 2015 to 2016. His undergraduate studies were completed at UCLA. Dr. Goenjian is fluent in English and Armenian, and can speak, read, and write in Spanish with basic competence.

Omid Omidvar, M.D.
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Dr. Omidvar has been conducting trials as an investigator at the Long Beach location since 2008. His research has focused on neurological conditions, an area which he was initially drawn to because of the multitude of neurological conditions that were lacking a therapeutic answer. Dr. Omidvar has executed many complex trials involving imaging and electrophysiologic assessments. He also has a strong background in medical devices.
Work History
Dr. Omidvar has served as an investigator in over 175 trials, including over 75 Phase I/IIa trials. His study experience includes the indications of Parkinson’s, Alzheimer’s, MS, Huntington’s, and ataxias as well as migraine and other pain disorders. Dr. Omidvar has been in private practice as a physician with Southland Neurologic Associates since 2000. He has served as an Assistant Clinical Professor at the David Geffen School of Medicine at UCLA since 2000 and as a Clinical Instructor at UC Irvine since 2014. After finishing his residency in Neurology at Harbor-UCLA Medical Center, he later served as the department’s Chief Resident.
Dr. Omidvar has published many peer-reviewed articles and abstracts and has been part of several scholarly presentations at scientific meetings. He is also a recipient of the “Patients’ Choice Award.” He has been repeatedly listed in the “Consumers’ Guide to Top Doctors” and “Castle Connolly Top Doctors” and has been the recipient of an “Outstanding Teaching Award.” He is a member of the American Academy of Neurology as well as the California Medical Association.
Education
Dr. Omidvar is board certified in neurology. He received his medical degree, Diplôme d’État de Docteur en Médicine, from Faculté de Médecine de Rouen, France. He is fluent in English, French, and Farsi.

Nirav S. Patel, M.D.
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Dr. Patel has been conducting trials in the field of neurology as an investigator with CNS since 2008. He performs studies at the Long Beach location. He has a special interest in migraine, Alzheimer’s, MS, and stroke, and is a well-known speaker on these topics.
Work History
Dr. Patel has participated as an investigator in over 100 trials. His Phase I-IV study experience includes the indications of Alzheimer’s, epilepsy, migraine, MS, pain disorders, Parkinson’s, and stroke/post-stroke. Dr. Patel has been in private practice as a physician with Southland Neurologic Associates since 2004. He is an Assistant Clinical Professor of Neurology at the David Geffen School of Medicine at UCLA in addition to being on the Clinical faculty at University of California, Irvine in the department of Medicine. He has been awarded the “Outstanding Teaching Award” several times. Dr. Patel is the Medical Director of the Stroke program at Los Alamitos Medical Center and Fountain Valley Regional Medical Center. Additionally, he serves as the Section Chief of Neurology at Long Beach Memorial Medical Center. Dr. Patel has delivered many presentations and guest lectures as an invited speaker at conferences and medical centers. He is an active member of the American Academy of Neurology, Los Angeles Stroke Society, Orange County Stroke Society, and local organizations committed to the advancement of neurology. In 2012, U.S. News & World Reports named him as one of Southern California’s 100 Top Doctors. He is also a recipient of the “Patients’ Choice Award.” He has been repeatedly listed in the “Consumers’ Guide to Top Doctors” and “Castle Connolly Top Doctors.”
Education
Dr. Patel is board certified in neurology. He received his medical degree from the UCLA School of Medicine and completed his Residency, Chief Residency, and Stroke Fellowship at Harbor-UCLA Medical Center. He graduated cum laude from UC Riverside with his B.S. in Biomedical Sciences. He is fluent in English and Gujarati.

Steven H. Reynolds, D.O.
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Dr. Reynolds has served as a principal investigator at CNS since 2010, conducting trials at the Long Beach location. He has specialized in trials in healthy subjects as well as ethnobridging trials and internal medicine indications. Dr. Reynolds has extensive experience conducting complex Phase I and IIa studies.
Work History
Dr. Reynolds has participated as an investigator in over 200 trials, most of which have been Phase I or IIa. His experience includes specialized studies such as FIH, SAD/MAD, PK/PD, bioequivalence, DDI, food effect, and Japanese bridging. Dr. Reynolds has practiced family medicine since 1995 and is currently in private practice with Naples Medical Group Long Beach. He maintains a position as an 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 holds affiliations with Long Beach Memorial Medical Center, Miller Children’s Hospital, and Memorial Women’s Hospital. He’s a member of many professional organizations including the American Academy of Family Physicians and the California Academy of Family Physicians, Long Beach Chapter.
Education
Dr. Reynolds is board certified in family practice. He obtained his medical degree from Midwestern University, Chicago College of Osteopathic Medicine and an undergraduate degree in Microbiology from San Diego State University. He completed Family Practice Residency at Long Beach Medical Center in Long Beach, CA.

Lara Shirikjian, DO
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Dr. Shirikjian has been a principal investigator at CNS since 2014. She leads conduct of trials at the Torrance location, primarily in the area of psychiatry.
Work History
Dr. Shirikjian has been an Investigator for over 100 Phase I-IV trials. Her study experience includes the indications of schizophrenia, bipolar disorder, PTSD, anxiety, ADHD, depression, insomnia, migraine, smoking cessation, and more. Dr. Shirikjian began working at CNS as a research assistant shortly after finishing her undergraduate studies. She completed her residency at Harbor-UCLA Medical Center, serving as Chief Resident for one of the busiest psychiatric facilities in the nation. Subsequently, she worked as a psychiatrist in the Resnick Neuropsychiatric Hospital, UCLA’s flagship location for patient care in neuropsychiatry. Dr. Shirikjian is a member of numerous professional organizations advancing psychiatry, including Schizophrenia International Research Society, American Society of Clinical Psychopharmacology, and American Psychiatric Association.
Education
Dr. Shirikjian is board certified in psychiatry. She obtained her medical degree from Western University, and her undergraduate degree from UCLA.
Safety and quality are paramount
Our physicians have extensive backgrounds in their respective medical specialties and always prioritize patient safety.
Board-certified
200+ years of collective clinical trial experience
Assisted by expertly-trained medical staff

Trust our state-of-the-art facilities
80+ Inpatient Beds
39,000 square feet of facility space
PSG Lab and dedicated EEG rooms
Private Dosing Rooms
27+ beds in Ethnic Bridging unit
Locations
Los Alamitos, CA
3771 Katella Ave,
Suite 300
Los Alamitos, CA 90720
Monday – Friday 9am-5:30pm
Garden Grove, CA
12772 Valley View St.,
Suite 3
Garden Grove, CA 92845
Monday – Friday 9am-5:30pm
Torrance, CA
19401 S. Vermont Avenue,
Suite F-100
Torrance, CA 90502
Monday – Friday 9am-5:30pm
We’re a CenExel
Center of Excellence
Centers of Excellence provide unparalleled attention to detail to assure consistent and first-class quality in patient care. We have supported tens of thousands of studies, the variety and complexity of which have resulted in a great depth of experience for the principal investigators and research staff at each Center.
We deliver engagement, expertise, and results.
