Geoffrey Sinner, MD

Dr. Pereira is a board-certified adult psychiatrist who is dedicated to providing compassionate care for a wide range of mental health concerns. He received his Bachelor of Arts from Harvard University and his medical degree from The Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, where he graduated with the Department of Psychiatry's award of distinction. He went on to complete his psychiatric residency training at Northwell Health's Zucker Hillside Hospital, with a specialization in the assessment and treatment of obsessive compulsive disorder and related conditions. Dr. Pereira's clinical approach emphasizes building trust with his patients and working collaboratively to develop an individualized treatment plan. He uses medication management along with cognitive behavioral therapy, exposure and response prevention, psychodynamic psychotherapy, interpersonal psychotherapy, and supportive therapy as needed. His practice treats a wide range of conditions, including depression, anxiety, OCD, family and relationship struggles, and other mental health issues. He has been trained in a wide range of settings including inpatient, outpatient, emergency departments, and behavioral health crisis centers. He also has experience teaching and supervising medical students and psychiatry residents.

Amberly Chaplin, PMHNP, has experience practicing across multiple levels of psychiatric care, including outpatient, inpatient, emergency psychiatric services, and PHP/IOP settings. She brings a unique interdisciplinary background, having earned a Bachelor of Arts from Boston College and a Master of Arts in Psychology from Boston University School of Medicine, followed by licensure as a Licensed Mental Health Counselor (LMHC). She later completed both her Bachelor of Science in Nursing and Master of Science in Nursing in Psychiatric Mental Health at Northeastern University.

Amberly prioritizes creating a collaborative, supportive environment where patients feel heard and actively involved in their care. She values transparency and patient education, believing that shared understanding helps align treatment decisions with each individual’s personal goals, values, and lifestyle.

Amberly conducts thorough, structured initial evaluations that remain conversational and patient-centered, with careful attention to personal history and current concerns. She respects each patient’s lived experience and preferences when developing highly individualized treatment plans and, when appropriate, integrates holistic and nutritional approaches to complement traditional psychiatric care.

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Dr. Elaine Kwok is a board-certified Adult Psychiatrist who has been practicing for 9 years. She specializes in depression and anxiety and believes in a holistic approach to the wellness of both the mind and body. Dr. Kwok conducts a comprehensive and individualized assessment for each patient utilizing a combination of medication management, lifestyle changes, and coping skills, creating a safe and therapeutic environment to facilitate healing and growth .Dr. Kwok received her undergraduate degree from New York University and her medical degree from St. George's University. She then completed her residency training at Seton Hall University. After training, she worked in the inpatient and outpatient units at Capital Health Medical Center in Trenton, New Jersey. She was a voluntary faculty member and trained residents and medical students from Rutgers Robert Wood Johnson Medical School. She has training in Cognitive Behavioral Therapy and Dialectical Behavioral Therapy. She actively participates in her local community to provide education and training for mental health providers. Dr. Kwok strives to collaborate and address hindrances that may interfere with an individual's best self. She focuses on creating a strong therapeutic relationship to support and facilitate balance, lifestyle enhancement, and emotional well-being. She looks forward to getting to know you and embarking on this journey together.

Dr. Walter Piddoubny is a double boarded psychiatrist in Adult Psychiatry and Consultation Liaison Psychiatry. He completed his undergraduate degree at Stony Brook University followed by his medical degree at SUNY Buffalo School of Medicine and Biomedical Sciences. He completed his Psychiatry Residency at Stony Brook University Hospital followed by his fellowship in Consultation Liaison Psychiatry at Yale New Haven Hospital. Dr. Piddoubny has held academic appointment at Stony Brook University Hospital practicing as a consultant psychiatrist as well as Associate Program Director of the Psychiatry Residency Program. He has been actively involved in teaching and was awarded "Teacher of the Year" in 2018 by the psychiatry residents. Dr. Piddoubny's practice focuses on medication management. Typically, he offers this in conjunction with supportive or emotionally focused therapy during 30-minute follow-up visits. Occasionally, Dr. Piddoubny may believe that additional therapy is warranted and ask that you bring a therapist into your care team in order to provide the best possible outcome.‍

Dr. Mandel received his Bachelor of Arts and Doctor of Medicine degrees from the University of Pennsylvania. He completed his Residency in Psychiatry at Mount Sinai Medical Center in Manhattan. He has been board certified in psychiatry since 2001 and is a Life Fellow of the American Psychiatric Association. He has held numerous clinical and academic appointments including serving as Chairperson of Psychiatry at Huntington Hospital in Huntington, New York, and Assistant Professor of Psychiatry at Hofstra North Shore-LIJ School of Medicine.

Dr. Mandel has over 25 years of clinical experience treating all mental health conditions. He has a strong interest in mood and anxiety disorders, including work-related anxiety. He authored a section on the pharmacology of social anxiety in the book Work Makes Me Nervous. Dr. Mandel also has expertise working with clients diagnosed with borderline personality disorder. He has lectured on the pharmacologic management of this condition, including a presentation at the NIMH International Think Tank for the More Effective Treatment of Borderline Personality Disorder.

Dr. Mandel continually seeks to streamline complex medication regimens. He has completed a fellowship in integrative psychiatry and carefully considers the potential contributions of lifestyle and nutrition to overall mental health and well-being. By taking an eclectic approach, Dr. Mandel is able to achieve the best possible outcome for all whom he is privileged to serve.

Severine Dondina, PMHNP-BC, is a board-certified psychiatric nurse practitioner with licensure in Washington and Florida. She holds a Master of Science in Nursing from the University of Alabama at Birmingham and graduated summa cum laude with dual bachelor’s degrees in nursing and biomedical science. Her background spans outpatient, community, forensic, and crisis psychiatry, including leadership roles with Florida’s Assertive Community Treatment (FACT) and Multi-Disciplinary Forensic Teams.

Currently serving patients in Washington, Severine treats adults with ADHD, anxiety, depression, PTSD, and bipolar disorder. She brings a trauma-informed, strengths-based approach to care and is deeply committed to creating affirming spaces for LGBTQ+ and gender-diverse individuals. Her clinical style combines evidence-based medication management with warm, collaborative support.

Trilingual in English, French, and Spanish, Severine is known for her cultural sensitivity, clinical rigor, and authentic presence. She approaches each patient with curiosity, humility, and respect—believing healing begins with connection.

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