Our Team

Dr. Matthew Siegel is a board-certified child and adolescent psychiatrist, assuming the role of Chief of Clinical Enterprise at Boston Children's Hospital and Chief Behavioral Health Officer at Franciscan Children's Hospital in January 2024. Dr. Siegel came to Boston Children's from MaineHealth, serving as a Vice President of Medical Affairs and leading an integrated continuum of care, research, and training for the behavioral health needs of youth with developmental disabilities. His research has focused on developing effective multi-disciplinary care for serious behavioral challenges and co-occurring psychiatric disorders in youth with developmental disabilities and characterizing those with profound autism. He founded and is the principal investigator of the Autism and Developmental Disorders Inpatient Research Collaborative (A.D.D.I.R.C.). He founded the first learning health network of inpatient units serving people with developmental disabilities. He has advised multiple state and federal agencies, hospitals, and academic departments on developing evidence-based mental health services for children and families. He is a scientist member of the N.I.H. Interagency Autism Coordinating Committee and an author of the American Academy of Child and Adolescent Psychiatry's practice guidelines for autism and for intellectual disability.

The main focus of Helen Tager-Flusberg's research for more than four decades has been on defining the neurocognitive and developmental bases of the language, communication, and associated social-cognitive deficits in autism spectrum disorder (A.S.D.) and other neurodevelopmental disorders (including developmental language disorder [D.L.D.], reading impairment, Williams syndrome, Down syndrome, and Prader-Willi syndrome). Tager-Flusberg has explored the role of broader influences of I.Q., executive functions, and especially language on development in these populations and in typically developing children. Over the past decade, she has explored language impairments within subtypes of A.S.D. and across the full spectrum of language ability, compared to other populations, including D.L.D. and reading impairment. Her laboratory uses behavioral/cognitive methods, structural imaging (magnetic resonance imaging [M.R.I.] and diffusion tensor imaging) methods, functional imaging (functional M.R.I. [fMRI] and functional near-infrared spectroscopy [fNIRS]), and electrophysiological methods (event-related potentials and electroencephalography) in individuals with A.S.D. and their first-degree relatives. More recently, her group has begun to translate some of their research findings into explorations of the influence of targeted interventions and the development of novel treatments and outcome measures. Over the past two decades, Tager-Flusberg has been the principal investigator on a number of major National Institutes of Health–funded multidisciplinary research programs on A.S.D., including two Collaborative Programs of Excellence in Autism (C.P.E.A.s), a Studies to Advance Autism Research & Treatment (S.T.A.A.R.T.) center and an Autism Center of Excellence (A.C.E.) at Boston University.

Dr. Frazier is a licensed clinical psychologist and the father of a young adult son with profound autism. He joined Cleveland Clinic in 2006 and from 2013-2017 was the director of the Cleveland Clinic Center for Autism and the Lerner School providing behavioral intervention to children and young adults. In 2017, he was hired as the Chief Science Officer at Autism Speaks and is currently a member of the Autism Speaks national board and chair of the medical and science advisory committee. He is also a professor of psychology at John Carroll University and a research professor of pediatrics and psychiatry at SUNY-Upstate. Over the last decade, Dr. Frazier has maintained active clinical research programs focused on evaluating and treating neurodevelopment disorders and related conditions. He has published more than 150 scientific papers and his recent work has focused on measuring key neurobehavioral processes relevant to early identification and monitoring response to intervention. He received his Ph.D. from Case Western Reserve University in 2004.

Dr. Call received his doctorate in school psychology from the University of Iowa in 2003. He has been at Marcus Autism Center since 2006, where he has held many positions as a clinician and as a leader of treatment programs. Dr. Call has an active research agenda that includes publishing in and serving on the editorial board for several journals, including as an associate editor for Behavior Analysis: Research and Practice. Dr. Call’s current research interests include the assessment and treatment of severe behavior disorders. He is a strong proponent of disseminating behavioral treatments to broader audiences, which has led him to serve as principal investigator on several federally funded randomized clinical trials. Dr. Call has also conducted translational research in behavioral economics and measure development.

Dr. Hagopian is a research scientist and Program Director of the Neurobehavioral Programs. This includes the Neurobehavioral Unit, which provides intensive inpatient treatment for individuals with intellectual disabilities who exhibit self-injury, aggression, and other problem behavior. He is a professor in the Division of Behavioral Biology in the Department of Psychiatry and Behavioral Sciences at The Johns Hopkins University School of Medicine. Dr. Hagopian is a board-certified Behavior Analyst. Dr. Hagopian received his PhD in Clinical Psychology from Virginia Polytechnic Institute and State University; he was also a National Institutes of Health Fellow. He completed a pre-doctoral internship at the Kennedy Krieger Institute and in the Department of Pediatrics at Johns Hopkins University School of Medicine. Dr. Hagopian's clinical and translational research has focused on understanding and treating problems related to behavioral dysfunction in IDD. The National Institutes of Health has funded his research continuously since 2004. This research crosses disciplines and seeks to understand the interaction of biological and environmental factors related to behavioral dysfunction in IDD. This includes research grants on behavioral deficits in autism, neuroimaging research on the reward system in autism, evaluation of generalization of behavioral treatments, identification of subtypes of automatically maintained self-injury, and currently, a clinical trial for treatment-resistant variants of self-injury. Dr. Hagopian has published his research in over 30 different peer-reviewed behavioral and medical journals.