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.