Symptom network analysis of anxiety and depression in epilepsy

Anxiety symptoms and depressive symptoms are frequent in PWE and associated with poorer outcomes. Investigation of specific characteristics of anxiety and depressive symptoms in PWE is of interest.

We used psychometric analyses in symptom networks using screening tools validated in PWE: Generalized Anxiety Disorder 7 (GAD-7) and Neurological Disorders Depression Inventory for Epilepsy (NDDI-E). We conducted an estimation to build the NDDIE and GAD-7 network, analyzed network inferences (especially centrality measures) and performed network robustness analyses as well as modularity-based community detection.

145 PWE were included. The criteria with highest centrality was "Trouble relaxing" (G4) from the GAD-7, which represents a possible substantial symptom at the interface of anxiety and depressive comorbidities in epilepsy. Robustness was very moderate, despite results consistent with the literature. The two communities of nodes corresponded to criteria of the two scales.

Epilepsy is a unique model for studying psychiatric symptoms since correlation with cerebral mechanisms can be assessed. "Trouble relaxing" as a key symptom is of interest, since this relates to the "Arousal" construct of the RDoC. Limitations of this study are the number of patients, single population, limits of psychometric analysis and network analysis, and a moderate robustness. Nevertheless, arousal is linked to seizure control, and thus these observations are of relevance to future investigation of pathophysiological mechanisms of psychopathology in epilepsy.