The differences of event-related potential components in patients with comorbid depression and anxiety, depression, or anxiety alone

There was a high comorbidity rate of major depressive disorder (MDD) and generalized anxiety disorder (GAD), showing a poor prognosis and significant detrimental impact on functioning. The study aimed to find whether patients with comorbid GAD and MDD had some differences in cognitive functions from patients with MDD or GAD alone.360 adult patients were enrolled from inpatient department of psychiatry from 2020 to 2022. They were divided into three groups with 120 patients for each group: MDD, GAD, and MDD + GAD. All the patients completed psychological evaluation scales including patient health questionnaire-9 (PHQ-9) and 7-item generalized anxiety disorder (GAD-7). All the patients underwent examinations of auditory brainstem response and event-related potentials (ERPs).In MDD + GAD group, P3b latency was significantly longer than patients with MDD alone, and P300 reaction time was positively correlated with total score of GAD-7 and PHQ-9, and PHQ-9 total score was also significantly positively correlated with P2-P3b amplitude (all p < 0.05). In addition, MDD patients had significantly longer P300 reaction time and lower P2-P3b amplitude than the GAD group (p < 0.05).It was a single-center and cross-sectional study, and we used self-report scales as assessment tools.Patients with MDD and GAD comorbidity might have a worse cognitive function than MDD patients, and the severity of cognitive impairments was positively correlated with the severity of anxiety and depression symptoms.