Department of Psychology

Clarissa W. Ong

Picture of Dr. Clarissa Ong

Ph.D., Utah State University, 2021
Assistant Professor and Director of the Psychology Clinic

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Mailing Address:
Department of Psychology
University of Toledo
2801 West Bancroft St.
Toledo, Ohio 43606-3390

Process-Oriented Intervention Science (POIS) Lab

Dr. Ong's CV can be viewed here.

Dr. Ong will not be accepting students for the Fall of 2024.

Research Interests

  • Process-based therapy
  • Acceptance and commitment therapy
  • Obsessive-compulsive and related presentations (e.g., perfectionism, hoarding)
  • Internet-based treatment
  • Assessment and measure performance

Selected Publications

Ong, C. W., Pierce, B. G., Klein, K. P., Hudson, C. C., Beard, C., & Björgvinsson, T. (2021). Longitudinal measurement invariance of the PHQ-9 and GAD-7. Assessment.

Ong, C. W., Krafft, J., Panoussi, F.†, Petersen, J. M., Levin, M. E., & Twohig, M. P. (2021). In-person and online-delivered acceptance and commitment therapy for hoarding disorder: A multiple baseline study. Journal of Contextual Behavioral Science, 20, 108-117.

Ong, C. W., Levin, M. E., & Twohig, M. P. (2020). Beyond acceptance and commitment therapy: Process-based therapy. The Psychological Record, 70, 637-648.

Ong, C. W., Blakey, S. M., Smith, B. M., Morrison, K. L., Bluett, E. J., Abramowitz, J. S., & Twohig, M. P. (2020). Moderators and processes of change in traditional exposure and response prevention (ERP) versus acceptance and commitment therapy-informed ERP for obsessive-compulsive disorder. Journal of Obsessive-Compulsive and Related Disorders, 24, 100499.

Ong, C. W., Lee, E. B., Krafft, J., Terry, C. L., Barrett, T. S., Levin, M. E., & Twohig, M. P. (2019). A randomized controlled trial of acceptance and commitment therapy for clinical perfectionism. Journal of Obsessive-Compulsive and Related Disorders, 22, 100444.

Ong, C. W.*, Pierce, B. G.*, Woods, D. W., Twohig, M. P., & Levin, M. E. (2018). The Acceptance and Action Questionnaire – II: An item response theory analysis. Journal of Psychopathology and Behavioral Assessment, 41, 123-134. (*co-first authors)

Ong, C. W., Clyde, J. W., Bluett, E. J., Levin, M. E., & Twohig, M. P. (2016). Dropout rates in exposure with response prevention for obsessive-compulsive disorder: What do the data really say? Journal of Anxiety Disorders, 40, 8-17.

Last Updated: 9/27/23