Variations in myo-inositol in fronto-limbic regions and clinical response to electroconvulsive therapy in major depression.
Though electroconvulsive therapy (ECT) is an established treatment for severe depression, the neurobiological factors accounting for the clinical effects of ECT are largely unknown. Myo-inositol, a neurometabolite linked with glial activity, is reported as reduced in fronto-limbic regions in patients with depression. Whether changes in myo-inositol relate to the antidepressant effects of ECT is unknown. Using magnetic resonance spectroscopy ((1)H-MRS), we measured dorsomedial anterior cingulate cortex (dmACC) and left and right hippocampal myo-inositol in 50 ECT patients (mean age: 43.78, 14 SD) and 33 controls (mean age: 39.33, 12 SD) to determine cross sectional effects of diagnosis and longitudinal effects of ECT. Patients were scanned prior to treatment, after the second ECT and at completion of the ECT index series. Controls were scanned twice at intervals corresponding to patients' baseline and end of treatment scans. Myo-inositol increased over the course of ECT in the dmACC (p = 0.042). A significant hemisphere by clinical response effect was observed for the hippocampus (p = 0.003) where decreased myo-inositol related to symptom improvement in the left hippocampus. Cross-sectional differences between patients and controls at baseline were not detected. Changes in myo-inositol observed in the dmACC in association with ECT and in the hippocampus in association with ECT-related clinical response suggest the mechanisms of ECT could include gliogenesis or a reversal of gliosis that differentially affect dorsal and ventral limbic regions. Change in dmACC myo-inositol diverged from control values with ECT suggesting compensation, while hippocampal change suggested normalization.
Ahmanson-Lovelace Brain Mapping Center, Department of Neurology, University of California Los Angeles, 635 Charles E Young Drive S #225, Los Angeles, CA, 90095, USA.
Stephanie
S
Njau
Ahmanson-Lovelace Brain Mapping Center, Department of Neurology, University of California Los Angeles, 635 Charles E Young Drive S #225, Los Angeles, CA, 90095, USA.
Shantanu H
SH
Joshi
Ahmanson-Lovelace Brain Mapping Center, Department of Neurology, University of California Los Angeles, 635 Charles E Young Drive S #225, Los Angeles, CA, 90095, USA.
Amber M
AM
Leaver
Ahmanson-Lovelace Brain Mapping Center, Department of Neurology, University of California Los Angeles, 635 Charles E Young Drive S #225, Los Angeles, CA, 90095, USA.
Megha
M
Vasavada
Ahmanson-Lovelace Brain Mapping Center, Department of Neurology, University of California Los Angeles, 635 Charles E Young Drive S #225, Los Angeles, CA, 90095, USA.
Jessica
J
Van Fleet
Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, 200 UCLA Medical Plaza #265, Los Angeles, CA, 90095, USA.
Randall
R
Espinoza
Ahmanson-Lovelace Brain Mapping Center, Department of Neurology, University of California Los Angeles, 635 Charles E Young Drive S #225, Los Angeles, CA, 90095, USA; Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, 200 UCLA Medical Plaza #265, Los Angeles, CA, 90095, USA. Electronic address: narr@ucla.edu.
Katherine L
KL
Narr
D000328:Adult; D003430:Cross-Sectional Studies; D003865:Major Depressive Disorder / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy*; D004565:Electroconvulsive Therapy / Q000379:methods*; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000378:metabolism*; D006801:Humans; D007294:Inositol / Q000378:metabolism*; D008032:Limbic System / Q000000981:diagnostic imaging / Q000378:metabolism*; D016014:Linear Models; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D014316:Tritium / Q000378:metabolism
D014316:Tritium; D007294:Inositol
Depression; Electroconvulsive therapy (ECT); Mood Disorders; Single voxel magnetic resonance spectroscopy (MRS)