Antidepressant treatment-related brain activity changes in remitted major depressive disorder

Electroencephalography (EEG) spectral signatures of selective serotonin reuptake inhibitors (SSRIs), selective norepinephrine reuptake inhibitors (SNRIs) and vortioxetine in major depressive disorder: A systematic review

BACKGROUND

Converging evidence suggests electroencephalography (EEG) methods may elucidate alterations in global structural and functional connectivity that underlie the pathophysiology of depressive disorders. Extant literature suggests SSRIs and SNRIs may broadly induce alterations to EEG-measured neural activity. Herein, this systematic review comprehensively evaluates changes to EEG spectral signatures associated with vortioxetine and each FDA-approved agent within the SSRI and SNRI class.

METHODS

We conducted a systematic review of studies investigating changes to EEG spectral signatures associated with SSRI, SNRI, and/or vortioxetine treatment in persons with MDD. Database search occurred from database inception to May 3, 2024.

RESULTS

Our search yielded 15 studies investigating overall spectral signature changes associated with SSRI- and/or SNRI-treatment. The existing literature presents with mixed findings. Notwithstanding, we did observe a pattern in which the SSRI and SNRI agents reproducibly affect EEG spectral signatures. We observed overlapping yet distinct spectral patterns for each agent within- and between-drug classes of SSRIs and SNRIs. Changes in resting/wake EEG were also observed.

LIMITATIONS

The findings from our systematic review are mixed. Heterogeneity exists with sample size, composition, dosing of antidepressants, duration of antidepressant exposure, as well as the type of EEG devices used.

DISCUSSIONS

Our findings provide support to the notion that although SSRIs, SNRIs and vortioxetine block reuptake of the serotonin transporter; they are different in their profile of pharmacology as evidenced by differential EEG signatures. EEG changes associated with SSRIs, SNRIs and vortioxetine are also highly replicated findings across mixed studies and populations.

Shared and distinctive dysconnectivity patterns underlying pure generalized anxiety disorder (GAD) and comorbid GAD and depressive symptoms

The resting-state connectivity features underlying pure generalized anxiety disorder (GAD, G1) and comorbid GAD and depressive symptoms (G2) have not been directly compared. Furthermore, it is unclear whether these features might serve as potential prognostic biomarkers and change with treatment. Degree centrality (DC) in G1 (40 subjects), G2 (58 subjects), and healthy controls (HCs, 54 subjects) was compared before treatment, and the DC of G1 or G2 at baseline was compared with that after 4 weeks of paroxetine treatment. Using support vector regression (SVR), voxel-wise DC across the entire brain and abnormal DC at baseline were employed to predict treatment response. At baseline, G1 and G2 exhibited lower DC in the left mid-cingulate cortex and vermis IV/V compared to HCs. Additionally, compared to HCs, G1 had lower DC in the left middle temporal gyrus, while G2 showed higher DC in the right inferior temporal/fusiform gyrus. However, there was no significant difference in DC between G1 and G2. The SVR based on abnormal DC at baseline could successfully predict treatment response in responders in G2 or in G1 and G2. Notably, the predictive performance based on abnormal DC at baseline surpassed that based on DC across the entire brain. After treatment, G2 responders showed lower DC in the right medial orbital frontal gyrus, while no change in DC was identified in G1 responders. The G1 and G2 showed common and distinct dysconnectivity patterns and they could potentially serve as prognostic biomarkers. Furthermore, DC in patients with GAD could change with treatment.