Dynamics of Spectral-Coherent EEG Parameters in the Process of Therapy of Endogenous Depression in Young Female Patients

Background: the need to study and clarify the neurobiological basis of depression is due to the widespread prevalence and heavy socioeconomic burden of this disease. In order to prevent relapses, it is recommended to continue treatment for depression for a long time after the relief of the main depressive symptoms. The study of neurobiological pathways of depression showed a significance of EEG parameters for diagnosis and prognosis. However, delayed EEG changes have been almost completely unstudied. The aim of the study was to analyze the dynamics of spectral-coherent EEG parameters during long-term therapy for endogenous depression in young female patients. Patients and Methods: The study included 20 female patients aged 16–25 years who underwent quantitative clinical (using the HDRS-17 and GAF scales) and neurophysiological (multichannel resting EEG with subsequent analysis of absolute spectral power (SP) and EEG coherence). Examination underwent three times: upon admission to hospital for treatment before the start of the course of therapy (at visit 1), upon discharge from the hospital at the stage of establishing remission (at visit 2) and one year after discharge from the hospital on maintenance therapy (at visit 3). Methods: clinical-psychopathological, psychometric, neurophysiological, statistical. Results: after the course of stopping therapy (at visit 2), there was a significant (p < 0.01) reduction in depressive symptoms with further improvement in the clinical condition (according to the HDRS-17 scale) and social functioning (according to the GAF scale) a year later (at visit 3). This was associated with an EEG slowdown in the form of a generalized increase in the SP of theta-delta activity, which was significant (p < 0.05) in the frontal-central leads, and a significant (p < 0.05) decrease in the alpha2 and alpha3 components of the alpha rhythm in the occipital zones. The same EEG pattern, including a significantly increased SP of theta2 sub-band in the centralparietal-occipital leads, persists a year later (at visit 3). Conclusion: the observed EEG changes are assessed as a reection of a complex restructuring of brain activity into a mode more adequate for these patients, ensuring the suppression of depressive symptoms and restoration of the social functioning of patients.