(PS2-68) Changes in the Symptom Networks of Obsessive-compulsive Disorder During Exposure and Response Prevention Therapy

While exposure and response prevention (EX/RP) is considered the gold standard treatment for obsessive-compulsive disorder (OCD), further research is needed to examine how OCD symptoms change during the course of EX/RP. Network analysis can provide a method for exploring the dynamic interrelationships and reciprocal influences among OCD symptoms. This study used network analysis to investigate how individual OCD symptom networks change in adults with OCD as they received EX/RP treatment.  

Data were combined across four NIMH-funded clinical trials that provided EX/RP to adults with OCD, resulting in a study sample of 334 patients. All participants received manualized EX/RP and were evaluated for OCD symptom change using the Yale Brown Obsessive-Compulsive Scale (Y-BOCS) by independent evaluators at three time points: before EX/RP; midway through treatment; and post-treatment. We constructed OCD symptom networks based on Y-BOCS items assessed at baseline, midpoint, and post-treatment for (a) the entire sample and (b) three different EX/RP trajectory response classes (dramatic, moderate, little-to-no progress) that were identified in a previous study (Kim et al., 2023).

Network analysis results revealed a unique modular structure with two distinct modules of OCD symptoms at baseline: module 1 related to resistance and control over obsessions and compulsions, and module 2 related to interference and distress due to obsessions and compulsions. These two modules merged at post-treatment for the total sample. Follow-up analysis found that this was true only for treatment responders. There was also a decrease in modularity (i.e., a more interconnected and adaptive network structure), an increase in global efficiency (i.e., greater integration in the interconnectedness of different OCD symptoms), and an increase in degree centrality (i.e., a notable shift in the connectedness of OCD symptoms) in the OCD symptom networks, especially in the dramatic and moderate progress groups.

 
This is the first study to apply network analysis to investigate changes in OCD symptoms during outpatient EX/RP treatment. This analysis identified two distinct symptom clusters at baseline (control of obsessions and compulsions versus distress and interference) that map onto different neurocircuitry both implicated in OCD. Although causality cannot be inferred, one interpretation is that successful treatment involved a mutually reinforcing positive cycle in which successful control of obsessions and compulsions reduced interference and distress, and vice versa. Methodologies that study the temporal precedence of change in these OCD symptom clusters during EX/RP both at the level of the brain and of behavior are recommended to understand the potential causal relationship.