Altered resting-state EEG microstate dynamics are associated with auditory hallucinations in patients with major...

Auditory hallucination experiences are an understudied but clinically significant feature of major depressive disorder (MDD). Although EEG microstate abnormalities have been reported in MDD, their relationship with auditory hallucination experiences remains unclear. This study investigated resting-state EEG microstate dynamics associated with auditory hallucination experiences in first-episode MDD.

A total of 182 first-episode patients with MDD and 95 healthy controls underwent resting-state EEG recordings. Patients were classified according to lifetime history of auditory hallucination experiences into those with (AH+, n = 42) and without (AH-, n = 140) such experiences. Patients were either psychotropic medication-naïve or minimally medicated (<2 weeks of cumulative exposure). Microstate parameters were compared among groups. ANCOVA and hierarchical binary logistic regression were performed to examine associations with auditory hallucination experiences.

Only microstate C occurrence was significantly higher in the AH+ group than in both the AH- and healthy control groups after multiple-comparison correction. This difference remained significant after adjustment for age, sex, education, and depression severity. Hierarchical logistic regression showed that higher microstate C occurrence was independently associated with auditory hallucination experiences (OR = 1.773, 95% CI: 1.211-2.595, p = 0.003), but not with hallucination severity. Its discriminatory ability was modest (AUC = 0.614, 95% CI: 0.516-0.711).

In first-episode MDD, a lifetime history of auditory hallucination experiences was associated with increased microstate C occurrence. This finding suggests that altered microstate C dynamics may represent an electrophysiological correlate of auditory hallucination experiences, warranting further investigation.