Department of Psychology

Clarissa W. Ong

Picture of Dr. Clarissa Ong

Dr. Ong will be joining the Department of Psychology in August 2022

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

Google Scholar

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

Dr. Ong's CV can be viewed here.

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: 6/27/22