V-092 | Structural Connectivity Association with Response to Electroconvulsive Therapy in Major Depression

Disorders of the Nervous System
Author: María Eugenia Samman | Email: mariaeugeniasamman@gmail.com

María Eugenia Samman^1°,2°, Leticia Fiorentini^1°,4°, María Lucía Fazzito^6°, Aki Tsuchiyagaito^7°, Elsa Costanzo^1°,4°, Joan A. Camprodon^8°, Cecilia Forcato^2°, Salvador M. Guinjoan^1°, Mirta F. Villarreal^1°,3°,5°, María Eugenia Samman^1°2°, Leticia Fiorentini^1°4°,María Lucía Fazzito^1°, Aki Tsuchiyagaito^1°, Elsa Costanzo^1°4°, Joan A. Camprodon^1°, Cecilia Forcato^2°, Salvador M. Guinjoan^1°, Mirta F. Villarreal^1°3°

^1° Grupo de Investigación en Neurociencias Aplicadas a las Alteraciones de la Conducta (Grupo INAAC), Instituto de Neurociencias FLENI-CONICET, Argentina.
^2° Laboratorio de Sueño y Memoria, Departamento de Ciencias de la Vida, Instituto Tecnológico de Buenos Aires (ITBA), Buenos Aires, Argentina.
^3° Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
^4° Servicio de Psiquiatría, Fleni, Argentina.
^5° Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
^6° NeuroMood | Psiquiatría intervencionista. Buenos Aires, Argentina.
^7° Laureate Institute for Brain Research, Oklahoma, United States of America.
^8° Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.

Electroconvulsive Therapy (ECT) is the most effective option for treatment-resistant depression (TRD) and certain brain regions are critical nodes in the pathogenesis of this condition. In this study, we investigated whether the structural connectivity between seven bilateral node regions (thalamus- Tha, amygdala- Amy, orbitofrontal cortex- OFC, posterior cingulate cortex- PCC, posterior ventrolateral prefrontal cortex- pvlPFC, anterior insula- aINS, and subcallosal gyrus- SG) is related to depressive symptomatology and clinical response to ECT. Diffusion-weighted magnetic resonance images were acquired before ECT sessions in 25 TRD patients. The Hamilton Depression Rating Scale was used to assess the severity of depression before and after ECT. Using probabilistic tractography analysis, we explored possible associations between the connectivity of the selected regions and two metrics: the basal symptomatology and the response to treatment. The results indicate that connectivity between the left Tha and right PCC, and between the left PCC and the right Tha was related to initial severity. Furthermore, bilateral Tha connectivity with the left PCC correlated with the level of treatment response. We also found significant associations of OFC, anterior aINS and pvlPFC with the degree of depressive symptomatology and treatment response, although not surviving FDR correction.