Our Staff

Reza Tadayon-Nejad, MD, PhD

Program Director

Dr. Tadayon-Nejad is an Assistant Clinical Professor of Psychiatry at UCLA and Visiting Associate faculty in Neuroscience at California Institute of Technology.

His clinical focus is on treatment of refractory OCD, depression, and comorbid OCD-Depression by using multimodal treatment options of Transcranial Magnetic Stimulation (TMS), advanced pharmacology and Exposure and Response Prevention therapy. He has been treating patients in the UCLA Obsessive-Compulsive Disorder Intensive...

Shana Doronn, LCSW, PsyD

Program Coordinator, Cognitive-Behavioral Therapist

Shana Doronn LCSW, PsyD is the Program Coordinator and a licensed Clinical Social Worker and Doctor of Psychology in the UCLA OCD Intensive Treatment Program. She worked in the program from 2003-2008 and returned January 2013.
Ana Ribas, PhD

Assistant Clinical Director, Cognitive-Behavioral Therapist

Dr Ana Ribas is the Assistant Clinical Director of the UCLA Adult OCD Intensive Treatment Program, and a licensed psychologist. She is also a cognitive-behavioral therapist and clinical supervisor in the program, bringing over 20 years of clinical experience with a variety of clinical issues in both the US and Europe, including 8 years as a staff psychologist at UCLA Counseling and Psychological Services.
Kristen McDonald, Ph.D.

Cognitive-Behavioral Therapist

Dr. Kristen McDonald is a licensed psychologist and cognitive-behavioral therapist at the UCLA Adult OCD Intensive Treatment Program. She brings over 15 years of clinical experience, including roles as Program Director for the Psychosocial Rehabilitation clinic at the VA Palo Alto and most recently as the senior psychologist for the UCLA CAPS satellite clinic at the Behavioral Wellness Center.

Tom J. Cohn, LMFT

Cognitive-Behavioral Therapist

Tom Cohn is a licensed Marriage and Family Therapist and Clinical Specialist working in the UCLA OCD Intensive Treatment Program, providing individual and group therapy. For the past 15 years, Tom has been treating anxiety and mood disorders, trauma and relationship issues in individuals, couples and families, both in Europe and the US.

Margaret Distler, MD

Dr. Distler is a psychiatrist and helps patients in the UCLA OCD IOP with medication management. She earned her MD and PhD from the University of Chicago. Her PhD studies focused on the genetic and molecular basis of anxiety. She completed her psychiatry residency at UCLA, where she was the chief resident in the Anxiety Disorders Clinic and participated in clinical and basic research on anxiety and depression. Dr. Distler has several clinical duties in addition to her work in the OCD IOP.

Denise Nelson, PhD

Family Cognitive-Behavioral Therapist

Denise Nelson, Ph.D. is a licensed clinical psychologist. She runs the program’s family education and support group; she also conducts initial interviews to evaluate a patient’s appropriateness for treatment in the program.
David Kronemyer PhD

Dr Kronemyer is on the clinical faculty of the UCLA Anxiety Disorders Program and the Obsessive-Compulsive Disorder (OCD) Intensive Outpatient Program (IOP). He also has an appointment at UCLA as a research scientist. His main role at the OCD IOP is patient evaluation and assessment. His research interests are: