Our Staff

Reza Tadayon-Nejad
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 Treatment Program since 2017.

Dr. Tadayon-Nejad is also the director of UCLA OCD Deep Brain Stimulation (DBS) program in collaboration with UCLA department of neurosurgery.

Shana Doronn, LCSW, PsyD

Program Coordinator, Cognitive-Behavioral Therapist

Shana Doronn LCSW, PSY.D is 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. Dr. Doronn specializes in treating children, adolescents and adults diagnosed with OCD and other anxiety disorders, (as well as patients diagnosed with a variety of chronic and terminal illnesses).

Dr. Doronn grew up in Southern California and received her MSW at USC and her PSY.D at Universityof San Francisco. Dr. Doronn frequently presents on OCD and related disorders in workshops and symposiums throughout the country. She was also a featured therapist on A&E’s reality documentary “Obsessed” from 2008-2010. In addition to her current work in the OCD Intensive Treatment Program...

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, working with students with anxiety, OCD and mood disorders. Dr Ribas heads cognitive and psycho-educational groups, and provides supervision in the treatment of OCD and related disorders to the behavioral coaches of the program. In addition to being part of the OCD treatment team, Dr Ribas also maintains a private practice in Beverly Hills, where she specializes in OCD, anxiety, mood...

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. Originally born in Germany, Tom received his undergraduate degree at University College London (UCL). He trained as a Systemic Family Therapist at the Institute of Family Therapy and Birkbeck College, University of London, England. In his first MFT appointment he trained in and provided CBT to Sickle Cell and Thalassemia patients and developed Cultural Awareness and Communication Skill courses for healthcare providers.

In 2010, Tom was recruited...

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 specializes in integrating behavioral treatments, such as Exposure and Response Prevention, into a comprehensive and individualized treatment program that is grounded in human kindness and collaboration. Dr. McDonald also serves as an Assistant Clinical Professor for the UCLA Psychology Department, with a focus on clinical supervision and training. She has a background in psychosocial rehabilitation and the treatment of mood, anxiety, sleep, and thought-disorders in both young and older adult populations, including 6 years in leadership and clinical roles at the VA Palo Alto Health Care System and 5 years at UCLA Counseling and Psychological...

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. She directs the Anxiety Disorders Clinic, an outpatient program, treats college students with mental illness, and is the medical director of the UCLA Aftercare program, where she treats patients with first-episode schizophrenia.

Denise Nelson, PhD

Family Cognitive-Behavioral Therapist

Denise Nelson, Ph.D. is a licensed clinical psychologist. At the UCLA OCD Intensive Treatment Program, she runs the family education and support group; she also conducts initial interviews to evaluate a patient’s appropriateness for treatment in the program. Previously, Dr. Nelson was also a therapist in the UCLA Child/Adolescent UCLA OCD Intensive Treatment Program.

Dr. Nelson graduated Phi Beta Kappa from the University of Chicago. Thereafter, she earned her Ph.D. in Clinical Psychology from the University of California, Los Angeles. Dr. Nelson has published several academic papers, given numerous conference presentations, and received a National Research Service Award.

Dr. Nelson has worked in the area of anxiety disorders for over 17 years. She is on the clinical...

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:

  • Emerging brain stimulation technologies and neurological interventions for patients with persistent psychiatric issues;
  • Problematic epistemic styles, particularly as expressed in psychiatric syndromes characterized by intrusive thinking and difficulties with emotion modulation;
  • Translational applications of concepts derived from cognitive science, philosophy of psychology, philosophy of mind and semiotics with an emphasis on Wittgenstein, Heidegger,...