(PS7-C58) I’ve Seen Something Very Similar Before: Behavioral Pattern Separation in Risk and Treatment of Obsessive-compulsive Disorder

Background:  Behavioral pattern separation captures one’s ability to differentiate newly encountered stimuli from highly similar ones from the past. As a facet of memory encoding that facilitates the integration of old and new information, poor behavioral pattern separation has been identified as a compelling predictor of overgeneralization of fear, and therefore a candidate risk factor in anxiety and related disorders (e.g. Bernstein et al., 2019; Bernstein & McNally, 2018; Caulfield et al., 2021). Nonetheless, limited research has studied behavioral pattern separation in obsessive-compulsive disorder (OCD), and it remains unknown if it is a robust marker of transdiagnostic risk and a plausible treatment target. The current study thereby examined the relationship of behavioral pattern separation to OCD symptoms and treatment outcomes.

Methods: Patients in an intensive/residential treatment (I/RT) program (N = 49) completed measures of OCD severity (Y-BOCS), trait worry (PSWQ-A), intolerance of uncertainty and threat overestimation (OBQ-44) at admission and discharge. They also completed the Mnemonic Similarity Task (Stark et al., 2013), a computerized task as a behavioral measure of behavioral pattern separation, at both timepoints.

Results: Pearson’s correlation coefficients revealed that behavioral pattern separation alone was not significantly associated with greater OCD severity at admission. However, there was a significant interaction between higher trait worry and poorer behavioral pattern separation that predicted more severe OCD symptoms at admission (β = -0.33, p < 0.01). The interactions of behavioral pattern separation with intolerance of uncertainty and with threat overestimation were not significant. In terms of its role in treatment, within-subject t-tests showed that patients’ behavioral pattern separation ability did not change significantly from admission to discharge, nor was it predictive of OCD symptom change across treatment. 

 


Discussion: To date, this was the first study that examined behavioral pattern separation in a treatment-seeking OCD population and evaluated its interaction with other cognitive vulnerabilities in OCD. Findings suggested that when combined with known cognitive vulnerabilities (such as trait worry) poor behavioral pattern separation may be a diathesis for more severe OCD. Together with trait worry, which might make an encoded memory more likely to be paired with distress, poor behavioral pattern separation could be particularly risky for the development of obsessions and the alleviation of anxiety through compulsions. Nonetheless, findings also showed that I/RT for OCD was still effective in reducing symptoms, even when attenuated behavioral pattern separation ability was present. Future studies should examine how mechanistically behavioral pattern separation links to trait worry, as well as evaluate if and how it impacts less intensive OCD treatments (i.e. outpatient therapy).