BOSTON — Behavioral avoidance could limit the long-term efficacy of exposure and response prevention (ERP), a widely used treatment for obsessive compulsive disorder (OCD), a new analysis shows.
Although avoidant patients with OCD reported symptom improvement immediately after treatment, baseline avoidance was associated with significantly worse outcomes 1 year later.
"Avoidance is often overlooked in OCD," lead investigator Michael Wheaton, PhD, an assistant professor of psychology at Barnard College in New York, told Medscape Medical News. "It's really important clinically to focus on that."
The findings were presented April 13 at the Anxiety and Depression Association of America 2024 Annual Conference and published online in the Journal of Obsessive-Compulsive and Related Disorders in April 2024.
The Avoidance Question
Although ERP is often included in treatment for OCD, between 38%-60% of patients have residual symptoms after treatment and as many as a quarter don't respond at all, Wheaton said.
Severe pre-treatment avoidance could affect the efficacy of ERP, which involves exposing patients to situations and stimuli they may usually avoid. But prior research to identify predictors of ERP outcomes have largely excluded severity of pre-treatment avoidance as a factor.
The new study analyzed data from 161 Norwegian adults with treatment-resistant OCD who participated in a concentrated ERP therapy called the Bergen 4-day Exposure and Response Prevention (B4DT) treatment. This method delivers intensive treatment over 4 consecutive days in small groups with a 1:1 ratio of therapists to patients.
B4DT is common throughout Norway, with the treatment offered at 55 clinics, and has been trialed in other countries including the United States, Nepal, Ecuador, and Kenya.
Symptom severity was measured using the Yale-Brown Obsessive Compulsive Scale (YBOCS) at baseline, immediately after treatment, and 3 and 12 months later. Functional impairment was measured 12 months after treatment using the Work and Social Adjustment Scale.
Although the formal scoring of the YBOCS does not include any questions about avoidance, one question in the auxiliary items does: "Have you been avoiding doing anything, going anyplace or being with anyone because of obsessional thoughts or out of a need to perform compulsions?"
Wheaton used this response, which is rated on a five-point scale, to measure avoidance. Overall, 18.8% of participants had no deliberate avoidance, 15% were rated as having mild avoidance, 36% moderate, 23% severe, and 6.8% extreme.
Long-Term Outcomes
Overall, 84% of participants responded to treatment, with a change in mean YBOCS scores from 26.98 at baseline to 12.28 immediately after treatment. Acute outcomes were similar between avoidant and non-avoidant patients.
But at 12-month follow-up, even after controlling for pre-treatment OCD severity, patients with more extensive avoidance at baseline had worse long-term outcomes — both more severe OCD symptoms (P = .031) and greater functional impairment (P = .002).
Across all patients, average avoidance decreased significantly immediately after the concentrated ERP treatment. Average avoidance increased somewhat at 3- and 12-month follow-up but remained significantly improved from pre-treatment.
Interestingly, patients' change in avoidance immediately post-treatment to 3 months post-treatment predicted worsening of OCD severity at 12 months. This change could potentially identify people at risk of relapse, Wheaton said.
Previous research has shown that pre-treatment OCD severity, measured using the YBOCS, does not significantly predict ERP outcomes, and this study found the same.
Relapse Prevention
"The fact that they did equally well in the short run I think was great," Wheaton said.
Previous research, including 2018 and 2023 papers from Wheaton's team, has shown that more avoidant patients have worse outcomes from standard 12-week ERP programs.
One possible explanation for this difference is that in the Bergen treatment, most exposures happen during face-to-face time with a therapist instead of as homework, which may be easier to avoid, he said.
"But then the finding was that their symptoms were worsening over time — their avoidance was sliding back into old habits," said Wheaton.
Wheaton would like to see the study replicated in diverse populations outside Norway and in treatment-naïve people. He also noted that the study assessed avoidance with only a single item.
Future work is needed to test ways to improve relapse prevention. For example, clinicians may be able to monitor for avoidance behaviors post-treatment, which could be the start of a relapse, said Wheaton.
Although clinicians consider avoidance when treating phobias, social anxiety disorder, and panic disorder, "somehow avoidance got relegated to item 11 on the YBOCS that isn't scored," Helen Blair Simpson, MD, PhD, director of the Center for OCD and Related Disorders at Columbia University, New York, New York, said during the presentation.
A direct implication of Wheaton's findings to clinical practice is to "talk to people about their avoidance right up front," said Simpson, who was not part of the study.
Clinicians who deliver ERP in their practices "can apply this tomorrow," Simpson added.
Wheaton reported no disclosures. Simpson reported a stipend from the American Medical Association for serving as associate editor of JAMA Psychiatry and royalties from UpToDate, Inc for articles on OCD and from Cambridge University Press for editing a book on anxiety disorders.