Are morphological changes necessary to mediate the therapeutic effects of electroconvulsive therapy?

Abstract

The neurotrophic hypothesis has become the favorite model to explain the antidepressant properties of electroconvulsive therapy (ECT). It is based on the assumption that a restoration of previously defective neural networks drives therapeutic effects. Recent data in rather young patients suggest that neurotrophic effects of ECT might be detectable by diffusion tensor imaging. We here aimed to investigate whether the therapeutic response to ECT necessarily goes along with mesoscopic effects in gray matter (GM) or white matter (WM) in our patients in advanced age. Patients (n = 21, 15 males and 7 females) suffering from major depressive disorder were treated with ECT. Before the start of treatment and after the completion of the index series, they underwent magnetic resonance imaging, including a diffusion-weighed sequence. We used voxel-based morphometry to assess GM changes and tract-based spatial statistics and an SPM-based whole-brain analysis to detect WM changes in the course of treatment. Patients significantly improved clinically during the course of ECT. This was, however, not accompanied by GM or WM changes. This result challenges the notion that mesoscopic brain structure changes are an obligatory prerequisite for the antidepressant effects of ECT.

White matter microstructural changes in adolescent anorexia nervosa including an exploratory longitudinal study

“…To replicate our results with a different analyses software, we also reanalyzed the data with Statistical Parametric Mapping (SPM8) as described by Nickl-Jockschat et al ( Nickl-Jockschat et al, 2015 ), (cf. supplementary material).…”

Electroconvulsive Therapy Induces Cortical Morphological Alterations in Major Depressive Disorder Revealed with Surface-Based Morphometry Analysis

“…Most evidence from animal models supported the neurotrophic hypothesis that the effect of ECT is partially mediated by seizure-induced neurotrophic effects, resulting in increased rates of neurogenesis, synaptogenesis and glial proliferation. [3][4][5][6] In addition, the neurotrophic effects may contribute to the antidepressant effect 9 and cognitive side effects. 7,8 These neurotrophic effects of ECT were detectable not only at the molecular and microstructural levels but also at the macroscopic level associated with brain structural changes.…”

“…16,17 However, a recent study using VBM did not identify changes in gray matter volumes in MDD patients after ECT even though the clinical symptoms were significantly improved. 9 Given that the measurement of gray matter volumes using VBM includes information of cortical thickness (CT), surface area (SA) and cortical folding, 18 delineating the exact changes in CT, SA and cortical folding in MDD patients after ECT will provide important insight to understand the mechanism of ECT.…”

Relationship Between Hippocampal Volume, Serum BDNF, and Depression Severity Following Electroconvulsive Therapy in Late-Life Depression

“…Some of these studies have also addressed structural changes in other brain areas relevant to depressive disorders, such as dorsolateral prefrontal cortex, orbitofrontal cortex (Jorgensen et al, 2015), lateral temporal cortex (Bouckaert et al, 2015), caudate nucleus (Bouckaert et al, 2015), and amygdala (Tendolkar et al, 2013;Jorgensen et al, 2015;Joshi et al, 2015;Ota et al, 2015;Sartorius et al, 2016). Only one study did not detect gray matter volume changes (Nickl-Jockschat et al, 2016).…”