Characterizing autogenous and reactive obsessions using theta and beta oscillations under inhibitory demands.

Obsessive-Compulsive Disorder (OCD) is a heterogenous mental health condition that causes significant impairment and is often associated with poor treatment outcomes. The aim of the current study was to examine the association between electroencephalographic (EEG) oscillatory power during inhibitory task performance and obsessive-compulsive symptoms (OCS). OCS was assessed using the well-established the Autogenous-Reactive Obsession (AO-RO) model as the main framework to address its heterogeneous clinical manifestations. The severity of AO and RO, as primary outcome measures, was indexed using the Revised Obsessive Intrusion Inventory (ROII). Cognitive- and behavioral inhibition (CI; BI) tasks were administered while EEG data were recorded from an analogue sample of 63 undergraduate students with OCS assessed along a dimensional spectrum. Oscillatory power was computed from frontal-central electrodes Fz and Cz for theta and beta frequency bands, using event-related spectral perturbations (ERSPs), which were entered into two hierarchical linear regression models to predict the severity of AO and RO, respectively, while controlling for covariates (i.e., sex, age, ethnicity, anxiety, depression, worry, and behavioral task performance). Theta power during CI (Theta-CI) was the only significant EEG predictor of AO severity, whereas beta power during BI (Beta-BI) was the only significant EEG predictor of RO severity. These results suggest that AO severity is primarily associated with an overactive neural correlate of cognitive control, whereas RO severity is primarily associated with an overactive neural correlate of behavioral cancellation. These results agree with previous literature suggesting overactive band power representing the dysfunction within OCD. Theta-CI and Beta-BI may serve as potential biomarkers differentially associated with AO and RO among undiagnosed individuals displaying varying levels of OCS, which warrants further investigation.