Association Between Anterior Cingulate Cortex Neurochemical Profile and Clinical Remission After Electroconvulsive Treatment in Major Depressive Disorder: A Longitudinal 1H Magnetic Resonance Spectroscopy Study.

BACKGROUND: The aim of the study was to assess anterior cingulate cortex (ACC) neurochemical profile of patients with unipolar major depressive disorder (MDD) before and after electroconvulsive therapy (ECT) by using 1H magnetic resonance spectroscopy (1H-MRS). METHOD: Using 1H-MRS, the metabolite levels of choline, glutamate + glutamine (Glx), myo-inositol, N-acetylaspartate, and total creatine were measured in ACC before and after 4-week ECT. The Montgomery-Åsberg Depression Rating Scale (MADRS) was implemented by blind raters to evaluate the efficacy of the treatment. Electroconvulsive therapy-remitter (ER) and nonremitter groups were compared using the 1-way repeated measures analysis of variance. RESULTS: Thirty patients with unipolar MDD (aged 41.3 ± 10.0 years, 66.7% female) were included in the study. The ER group (n = 16, 53.3%) and NR group did not differ regarding baseline Global Assessment of Functioning and MADRS scores. At the end of 4-week ECT treatment, results did not suggest any significant difference for metabolite levels in ACC. When compared with the NR group, the ER group had higher baseline levels of Glx (8.8 ± 1.8 vs 6.3 ± 2.0, P = 0.005) and total creatine (5.3 ± 0.6 vs 4.7 ± 0.5, P = 0.010). In addition, elevated baseline Glx (r = -0.68, P = 0.002) was associated with lower MADRS scores at the end treatment. Finally, the change in Glx levels was correlated with change in MADRS scores after ECT (r = 0.47, P = 0.049). LIMITATIONS: Modest sample size and 1H-MRS at 1.5 Tesla are limitations of the study. CONCLUSIONS: Results suggested that Glx levels could be a predictor of remission. Studies with larger samples should explore neurochemical correlates of ECT in unipolar MDD.