Response Versus Remission in Obsessive-Compulsive Disorder

Helen Blair Simpson, M.D., Ph.D.; Jonathan D. Huppert, Ph.D.; Eva Petkova, Ph.D.; Edna B. Foa, Ph.D.; and Michael R. Liebowitz, M.D.

Objective: To investigate rates of response and remission in adults with obsessive-compulsive disorder (OCD) after 12 weeks of evidence-based treatment.

Method: Post hoc analyses of response and remission were conducted using data from a multisite, randomized, controlled trial comparing the effects of 12 weeks of exposure and ritual prevention (EX/RP), clomipramine (CMI), their combination (EX/RP+CMI), or pill placebo (PBO) in 122 adults with OCD (DSM-III-R or DSM-IV criteria). Response was defined as a decrease in symptoms; remission was defined as minimal symptoms after treatment. Different response and remission definitions were constructed based on criteria used in prior studies. For each definition, the proportion of responders or remitters in each treatment group was then compared.

Results: There were significant differences (p < .05) among the 4 treatment groups in the proportion of responders and remitters. In pairwise comparisons, EX/RP + CMI and EX/RP each produced significantly more responders and remitters than PBO; CMI produced significantly more responders and remitters than PBO for some definitions but not for others. When remission was defined as a Yale-Brown Obsessive Compulsive Scale (YBOCS) score of 12 or less, significantly more EX/RP + CMI (18/31 [58%]) and EX/RP (15/29 [52%]) patients entering treatment achieved remission than either CMI (9/36 [25%]) or PBO (0/26 [0%]) patients. However, even in treatment completers, many CMI and some EX/RP + CMI and EX/RP patients did not achieve remission (remission rates for YBOCS < = 12: EX/RP + CMI = 13/19 [68%]; EX/RP = 15/21 [71%]; CMI = 8/27 [30%]; PBO = 0/20 [0%]).

Conclusion: EX/RP (with or without CMI) can lead to superior treatment outcome compared with CMI alone in OCD patients without comorbid depression. However, many OCD patients who receive evidence-based treatment do not achieve remission.

(J Clin Psychiatry 2006;67:269-276)

Received Feb. 9, 2005; accepted July 19, 2005. From New York State Psychiatric Institute, New York, (Drs. Simpson, Petkova, and Liebowitz); the Departments of Psychiatry (Drs. Simpson and Liebowitz) and Biostatistics (Dr. Petkova), Columbia University, New York, N.Y.; and the Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia (Drs. Huppert and Foa).

Supported in part by grants R01 MH45436 (Dr. Liebowitz), R01 MH45404 (Dr. Foa), and MH01907 (Dr. Simpson) from the National Institute of Mental Health, Rockville, Md.

These data were presented in part at the 25th annual meeting of the Anxiety Disorders Association of America, March 17-20, 2005, Seattle, Wash.

Dr. Liebowitz is a consultant for, has received grant/research support from, has received honoraria from, and has served on the speakers or advisory boards of GlaxoSmithKline, Pfizer, Eli Lilly, Wyeth, Solvay, and Forest, and has served on the speakers or advisory boards of Roche, Novartis, and UCB Pharma. Drs. Simpson. Huppert, Petkova, and Foa report no additional financial or other important affiliation relevant to the subject of this article.

The authors thank Andrew B. Schmidt, C.S.W., New York State Psychiatric Institute, and Ning Zhao, Ph.D., Department of Psychiatry, University of Pennsylvania School of Medicine, for expert data management and Randall Marshall, M.D., New York State Psychiatric Institute and Columbia University, for helpful comments on an earlier draft.

Corresponding author and reprints: Helen Blair Simpson, M.D., Ph.D., Anxiety Disorders Clinic, New York Psychiatric Institute, Unit 69, 1051 Riverside Dr., New York, NY 10032 (e-mail: simpson@nyspi.cpmc.columbia.edu).