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Child & Adolescent Faculty

Daniel Tucker, MD

Daniel Tucker, M.D.

Associate Professor

Chief of the Division of Child and Adolescent Psychiatry

As Chief of the Division of Child and Adolescent Psychiatry at his medical alma mater, he asserts a wealth of experience in general Child and Adolescent Psychiatry at all levels of the continuum of care, and brings his dedicated mission of keeping the best of “old” Psychiatry (talking and listening) to the best of “new” Psychiatry (modern diagnostics, psychopharmacology, inter-disciplinary collaboration, historic-socio-anthropologic perspectives, and a pragmatic, non-dogmatic approach) to treating children, adolescents, and their families.

His current research interests include post-infectious, immunologic aspects of Psychiatry, neuroimaging, Obsessive Compulsive Disorder, Tourette’s disorder, ADHD, and the Autism Spectrum Disorders. In his commitment to teaching the next generation of psychiatrists and nurturing in them the truest flame of his accumulated expertise, he brings dedication to leaving no effort unspent helping his patients.

Jorge Avila, MD

Jorge Avila, MD

Assistant Professor

Dr. Avila comes from the great state of Texas. He grew up along the Texas-Mexico border and is of Mexican heritage. He completed his undergraduate education at the University of Chicago. He then went on to complete his medical education at Universidad Central Del Caribe, in Bayamon, PR. After medical school he followed a long trajectory of taking the road less traveled and developed a career that has lead him to complete residency in General Psychiatry, fellowship in Child and Adolescent Psychiatry, and a fellowship in Addiction Medicine all at the University of Florida.

His clinical interests include child and adolescent depression and anxiety disorders, adult and adolescent substance abuse disorders. He is also interested in working with patients and their families using Family Therapy modalities and Cognitive-Behavior therapies, as well as psychopharmacological interventions. He has dual appointments in both the University of Florida’s Child and Adolescent Psychiatry Department and with the Florida Recovery Center.

Regina Bussing, MD

Regina Bussing, MD


Research Chief, Division of Child and Adolescent Psychiatry

Departments of Psychiatry and Pediatrics

Dr. Bussing’s major clinical interests include comprehensive treatment approaches to disruptive disorders of childhood, combining pharmacotherapy, parent training, clinical group therapies, and school interventions. She enjoys treating the entire spectrum of child and adolescent disorders.

Of special clinical interest is the comprehensive outpatient treatment of disruptive disorders of childhood, combining evidence-based pharmacological and psychosocial therapies. She adapted an established parent group intervention for ADHD, combining it with a child social skills group, into an eight-week manual-based program. Another related project has been the development of a school-problem clinic in conjunction with our psychology services. This clinic provides multidisciplinary assessment of the various school problems children get referred for, with comprehensive treatment planning including medication regimens, behavioral interventions, and tutoring.

Maria Constantinidou, Psy. D.

Maria Constantinidou, Psy. D.

Assistant Professor

Eating Disorder Recovery Center

Dr. Constantinidou, Assistant Professor specializes in the evaluation and treatment of Eating Disorders, OCD and Anxiety Disorders. Dr.  Constantinidou completed her residency at Rockland Psychiatry Hospital in New York, when she also became certified in treating PTSD using Cognitive Processing Therapy, as well as using Dialectical Behavioral Therapy treating inpatients with Borderline Personality Disorder.  In addition, she completed two years of postdoctoral training here at the University of Florida’s OCD clinic and Eating Disorders Recovery Center (EDRC).

She served a key role as a co-founder member of the UF’s EDRC. Since then, she has provided training lectures and on-going mentorship to clinical staff and nursing.  Constantinidou has also treated many complicated patients with comorbid eating disorders, OCD, Anxiety Disorders and Personality Disorders. While she runs the Skills and Body Image inpatient groups, she also supervises graduate students, and provides individual and group therapy in our outpatient clinic.

Constantinidou is also actively involved in the continuous development and expansion of UF’s eating disorders programs, and the enhancement of the academic curriculum to include elective graduate classes, APA approved internships, practicum sites, and community prevention programs.


Cindi Flores, Ph.D.

Assistant Professor

Dr. Flores earned a doctoral degree from the University of Florida’s graduate training program in School Psychology. Her graduate and postgraduate training include clinical activities across a variety of settings including the hospital, school, community, and legal clinic.

After earning her doctorate, she worked as a Psychology Resident and Postdoctoral Associate for the Division of Medical Psychology in the Department of Psychiatry at UF Health where she acquired specialty training in Cognitive Behavioral Therapy (CBT) and Exposure and Response Prevention (ERP). Dr. Flores’ current clinical and research interests are focused on the evaluation and treatment of Autism Spectrum Disorder and Obsessive Compulsive Disorder.

Additionally, she has special expertise in the behavioral treatment of individuals who have comorbid Autism Spectrum and Anxiety Disorders. Dr. Flores also has clinical expertise with dual disorder patients as the Co-Director of Medical Psychology’s consultation-liaison service for Psychiatry’s Partial Hospitalization Program for Substance Use Disorders at the Florida Recovery Center (FRC). Dr. Flores serves as the Division of Medical Psychology’s Director of School Psychology for school aged children and adolescents, though her clinical and research interests range across the lifespan.


Sarah Frazier, M.D.

Medical Director

Meridian Behavioral Health Center

Dr. Frazier completed both her Adult Psychiatry residency and Child and Adolescent Psychiatry fellowship at the University of Florida. She currently serves as the Medical Director for Meridian Behavioral Health and acts as the site supervisor for the Child Psychiatry fellows during their community mental health rotation. Dr. Frazier is a staunch patient advocate, working with large underserved populations. She has experience both with inpatient and outpatient Child Psychiatry and is a wonderful role model for the trainees. Her major focus is on mood and anxiety disorders, though she has worked with other populations, including disruptive behavior disorders and substance use/abuse.


Gary Geffken, PhD

Gary Geffken, Ph.D.

Associate Professor

Chief, Division of Medical Psychology

Departments of Psychiatry and Clinical and Health Psychology

Dr. Geffken completed a B.A. in Psychology at the University of Massachusetts in Amherst, and his M.A. and Ph.D. in Clinical Psychology at the University of Florida in Gainesville. His Internship was completed at the West Virginia University Medical Center, and he completed a postdoctoral fellowship in Clinical Child and Pediatric Psychology in the Department of Psychiatry at the University of Florida Medical Center.

Dr. Geffken directs the Cognitive Behavioral Therapy Clinic (CBT) for the UF-OCD program and is Chief of the Division of Medical Psychology. The CBT Clinic operates on an outpatient basis where patients with treatment refractory Obsessive Compulsive Disorder (OCD) are seen on a daily basis. Dr. Geffken also supervises a clinic that conducts weekly or biweekly outpatient Cognitive Behavioral Therapy (CBT) for Obsessive Compulsive Disorder, Panic Disorder, and other anxiety related disorders. He treats both children and adults, and has received additional training in Exposure-Response Therapy (ERP) from the Behavior Therapy Institute formed by the OC Foundation (OCF).

Susan Hill, MSN, ARNP

Susan M. Hill, M.S.N., A.R.N.P.

Assistant Professor

Departments of Psychiatry and Pediatrics

Affiliate Associate In Nursing, College of Nursing

Ms. Hill is an Advanced Registered Nurse Practitioner (ARNP) in Psychiatry. She brings to the faculty greater than 25 years of clinical and teaching experience in the field of Child Psychiatry and a strong medical background in Oncology and Palliative Care nursing.  She has previously served as the Administrative Assistant to the Child Psychiatry Division Chief from 1985 to 1999, directed daily operations on the Children’s Mental Health Unit for children with severe developmental disabilities, served as Director of the ADHD clinic, served on the Child Psychiatry Consultation-Liaison service to Pediatrics for 15 years, and currently provides clinical evaluation and treatment services in the Child and Adolescent Psychiatry Outpatient Clinic.

Ms. Hill has also served as the Medical Student Coordinator for their outpatient clinic rotation and currently continues to teach Medical students during their Psychiatry clerkship and elective rotations. Ms. Hill has also served as the research coordinator for two multi-center inpatient clinical trials; involving the use of Depakote in the treatment of patients with Bipolar Disorder and the treatment of memory loss in patients receiving Electro-Convulsive Therapy. She has been a member of the Department of Psychiatry Institutional Site Review Committee for the Florida Department of Children and Families (DCF), and has conducted site visits at DCF facilities. In addition, Ms. Hill lectures and provides clinical supervision in both the General Psychiatry Residency Training Program and Child Psychiatry Fellowship.

She currently serves as a Consultant to the Center for Autism and Related Disabilities (CARD) located at the University of Florida, regularly consulting with school districts and providing community outreach services and trainings on Autism and related issues. She is responsible for developing and integrating Medical Student and Resident training opportunities into the CARD model.  Ms Hill also holds faculty appointments in the Department of Pediatrics and in the College of Nursing. In addition to a broad background of clinical experience, she has special interest and expertise in treating children with Autism and related developmental disabilities.She is a committed clinician and teacher, who models a client-centered, capacity building, and advocacy-based approach to working with patients and families.

Isaac Isaac, MD

Isaac G. Isaac, M.D.

Assistant Professor

Director, Child Psychiatry Community Services

Dr. Isaac completed his Child and Adolescent Psychiatry fellowship in June 2011, after completing his general Adult Psychiatry residency at Louisiana State University (LSU). He has interests in ASD (Autism Spectrum Disorders) and works with the fellows in Autism Clinic.

In addition, Dr. Isaac is also interested in the comorbidity of ASD and anxiety and mood disorders, which is one of his areas of clinical specialty.

He also serves as a site supervisor for the Child Psychiatry fellows at Meridian Behavioral Health (community mental health), where the fellows spend part of their senior year treating an underserved population.

Joseph McNamara, PhD

Joseph McNamara, Ph.D.

Assistant Professor

Chief, Undergraduate Medical Education

Co-Director/Research Director, Division of Medical Psychology Clinic

Division of Child and Adolescent Psychiatry

Dr. McNamara’s training includes the completion of Ph.D. programs in both Counseling and Developmental Psychology, an Internship in Clinical and Health Psychology, and Psychology Residency in the Division of Medical Psychology at the University of Florida. Over the course of his training, he sought out an array of clinical experiences in a variety of settings such as counseling centers, psychiatric outpatient facilities, and hospitals. These training experiences provided him with a solid foundation for treating a variety of disorders from a cognitive behavioral perspective.

Moreover, Dr. McNamara has worked with patients across the lifespan, ranging from ages 4 to 83. He treats both children and adults and has received additional training in Exposure-Response Therapy (ERT) and Cognitive Behavioral Therapy (CBT). He has also received training in the treatment of insomnia. Within the teaching domain, Dr. McNamara is qualified to teach Cognitive Behavioral Therapy (CBT), therapeutic treatment of anxiety disorders, therapeutic treatment of depression, psychotherapy, supervision, and typical development.

McNamara conducts clinical research with patients as part of daily, biweekly, and weekly outpatient CBT for Obsessive Compulsive Disorder (OCD), Panic Disorder, and other anxiety related disorders. His research interests are concerned with the development of executive functioning, the role sleep plays in executive functioning, and the impact of executive function and sleep on 1) adherence to psychological recommendations, 2) medical regimen adherence, and 3) treatment outcome. Currently, Dr. McNamara’s research team currently has 26 undergraduate students working on a seven different research projects.

Mathew Nguyen, MD

Mathew Nguyen, MD

Assistant Professor

Medical Director and Associate Chief: Division of Child and Adolescent Psychiatry

Medical Director, Psychiatry and Psychology at Springhill Health Center

Medical Director and Chief, Eating Disorders Recovery Center

Chief, Pediatric Psychiatry Consultation-Liaison Services

Departments of Psychiatry and Pediatrics

Dr. Nguyen is the Medical Director and Associate Chief for the Division of Child and Adolescent Psychiatry, overseeing the various clinical services, and Chief of the Psychiatry Consultation/Liaison Services at Shands Teaching Hospital. He has also recently assumed leadership of the Eating Disorders Recovery Center and has begun expanding the program for both anorexia/bulimia and obesity, both in adults and children/adolescents.

His interests focus on Anxiety Spectrum Disorders in children, with knowledge in both pediatric psychopharmacology and various therapy modalities, including cognitive behavioral therapy and insight-oriented therapy.

Nguyen also focuses on psychotherapy training for the Child and Adolescent Psychiatry fellows. He supervises the trainees in behavioral modification, cognitive behavioral therapy (CBT), family therapy, interpersonal therapy (IPT) and psychodynamic psychotherapy: “A non-biological approach to Psychiatry in today’s atmosphere of newer medications and managed care is becoming more a lost art form, and it is important for our trainees to be able to conceptualize patients in a more global fashion.”

His other main area of interest involves the treatment of psychiatric illness in the medical setting. He is well-versed in treating medically and surgically complicated patients with co-morbid psychiatric illnesses, consulting to general services as well as the varied Intensive Care Units. As Chief of the Psychiatry Consultation/Liaison Services, he interfaces with the other major medical services within Shands to manage medically ill children and adolescents and also those patients with somatoform symptoms on the Child and Adolescent Psychiatry Inpatient Unit.

In addition to his administrative and clinical roles, Dr. Nguyen serves as the clerkship director for Psychiatry C/L and Child and Adolescent Psychiatry 4th year electives for MS-4s. He has a strong focus on medical student and resident education and has received several awards in these areas, including the William Rufkin Outstanding Resident Teacher Award, the Carlos E. Muniz Resident Mentor Award, and the UF College of Medicine Medical Student Exemplary Teaching Award.

Brian Olsen, PhD

Brian Olsen, PhD

Assistant Professor

Dr. Olsen completed his doctoral degree in the clinical psychology program at the University of Cincinnati. He came to the University of Florida to complete his internship in the department of Clinical and Health Psychology at the University of Florida. During his clinical training, Dr. Olsen specialized in working with patients with chronic medical conditions and their families across a variety of settings including pediatric hospitals, outpatient clinics, and schools. He then continued his training as a Psychology Resident and Postdoctoral Associate for the Division of Medical Psychology in the Department of Psychiatry at UF Health where gained specialty training in Cognitive Behavioral Therapy (CBT) with Exposure and Response Prevention (ERP).

Dr. Olsen’s primary research focus is geared toward understanding how individual, peer, and familial perceptions impact children’s coping strategies and treatment adherence. Dr. Olsen is currently conducting research assessing the impact of parenting styles and online health information seeking on health outcomes among children with Type I Diabetes. He is also part of a team examining treatment outcomes for children with OCD.

Mariam Rahmani, MD

Mariam Rahmani, MD

Assistant Professor

Assistant Child Psychiatry Residency Training Director

Division of Child and Adolescent Psychiatry


Dr. Rahmani comes from a multicultural background. She was born in Kuwait. She has lived in Kuwait, Pakistan, and the United Arab Emirates. She completed her undergraduate education at the University of Central Florida. She completed her medical education, residency in General Psychiatry, and fellowship in Child and Adolescent Psychiatry at the University of Florida. Her clinical interests include child and adolescent depression and anxiety disorders, and treating them using Interpersonal and Cognitive-behavior therapies as well as psychopharmacology. At local and national meetings, she has presented research on the use of clonidine for sleep in children and adolescents; the use of zonisamide for childhood obesity; cases of spice-induced psychosis; and the effects of early exposure to Community Psychiatry for medical students.

Dr. Rahmani is interested in advocacy for mental health and serving the community. She is a regular volunteer provider at the local Helping Hands Clinic for Gainesville’s indigent population. She is passionate about educating undergraduate students as well as training medical students, residents, and fellows in General and Child Psychiatry. She is involved in the curriculum development for Child Psychiatry fellows. She is also in charge of the Child Psychiatry lecture series provided to residents training in General Psychiatry.


Michael Shapiro, M.D.

Assistant Professor

Assistant Clinic Director

Child Psychiatry Clinic at Springhill Health Center, Department of Psychiatry

Assistant Medical Director, Psychiatry and Psychology at Springhill Health Center

Dr. Shapiro recently completed his Child and Adolescent Psychiatry fellowship at the University of Florida in 2013. He also completed Adult Psychiatry residency, medical school, and undergraduate training at UF.

He recently completed his Child PRITE fellowship (2011-2013) and currently is a member of the PRITE Editorial Board. Dr. Shapiro’s main interests include adolescent mental health, particularly in treating mood and anxiety disorders; he employs various modalities of individual and family therapy to improve communication and overall emotional well-being. Dr. Shapiro also has experience in treating ADHD, disruptive behavior disorders, and substance use disorders.

Dr. Shapiro serves as the site supervisor for Child Psychiatry at Family Preservations Services in Gainesville as well as the Marion County Juvenile Correctional Facility in Ocala as well as the Assistant Medical Director of Springhill Health Center

Kimberly White, MD

Kimberly White, M.D.

Assistant Professor

Child Psychiatry Program Director

Departments of Psychiatry and Pediatrics

Dr. White brings over 20 years of clinical practice across a continuum of care to her position in UF’s Division of Child & Adolescent Psychiatry. She has treated patients with a variety of disorders from ADHD, mood and anxiety disorders, to adolescent substance-use disorders.  Her special-interest populations include adolescents, emerging adults (18-25 years of age) and women who have experienced abuse and trauma.

Dr. White is also versed in various therapy modalities, including CBT, DBT, group, and family therapies. We have recently re-vamped the structure of the Child and Adolescent Psychiatry Inpatient Unit to integrate a DBT program to help those patients who can make use of this modality to learn coping strategies that they can take with them after discharge. The integration of the DBT model has received widespread positive feedback from both staff and patients and their parents.

Dr. White’s broad clinical experience with children, adolescents and adults includes intensive psychotherapy, partial hospitalization programs, outpatient services, residential treatment facilities, crisis stabilization units, private psychiatric services, and community mental health. Her clinical experience at UF has involved her practicing at the Shands Vista hospital facility, working as an expert for the State of Florida in treatment, and as a child psychopharmacologist. Dr. White is an outstanding psychiatrist, whose caring and calm demeanor and decades of experience have brought hope and help to many of UF’s outpatients.