Electroconvulsive therapy is associated with increased immunoreactivity of neuroplasticity markers in the hippocampus of depressed patients

Hippocampal microstructural changes following electroconvulsive therapy in severe depression

Electroconvulsive therapy (ECT) induces hippocampal volume increases in depressed patients, potentially reflecting neuroplasticity. We hypothesized that Neurite Orientation Dispersion and Density Imaging (NODDI) could provide in vivo evidence of hippocampal neuroplasticity following ECT. This longitudinal study evaluated 43 depressed patients undergoing ECT and 24 controls. MRI and clinical assessments were performed at baseline (V1), after 5 sessions (V2), and post-treatment (V3). Evaluations included a 3 T MR-scan with 3DT1-weighted and multi-shell diffusion (b = 200/1500/2500 s/mm², 30/45/60directions) sequences. Q-ball, Diffusion Tensor, and NODDI models provided: axial diffusivity (AD), radial diffusivity (RD), mean diffusivity (MD), fractional anisotropy (FA), generalized FA (GFA), neurite density index (NDI), isotropic fraction (Fiso), and orientation dispersion index (ODI). FreeSurfer extracted whole hippocampal and subfield volumes from T1-weighted images. Longitudinal changes were assessed with linear mixed-effect models. 107 MRIs from patients and 24 MRIs from controls were analyzed. ECT induced significant bilateral hippocampal volume increases (p < 0.001). Group comparisons showed consistently higher FA, lower GFA and ODI in patients compared to controls at all time-points. Following ECT, significant diffusion changes included decreased hippocampal GFA, FA, AD, MD and Fiso, along with increased ODI and NDI. NDI and Fiso changes were localized to the dentate gyrus but not the hippocampal tail. ECT responders showed a significant right hippocampal volume increase at V2 compared to non-responders. After ECT, hippocampal volume increases are accompanied by bilateral changes in NODDI parameters, particularly in the dentate gyrus, consistent with hippocampal neuroplasticity.

Blood biomarkers of neuronal injury and astrocytic reactivity in electroconvulsive therapy

Despite electroconvulsive therapy (ECT) being recognized as an effective treatment for major depressive episodes (MDE), its application is subject to controversy due to concerns over cognitive side effects. The pathophysiology of these side effects is not well understood. Here, we examined the effects of ECT on blood-based biomarkers of neuronal injury and astrocytic reactivity. Participants with a major depressive episode (N = 99) underwent acute ECT. Blood was sampled just before (T0) and 30 min after (T1) the first ECT session, as well as just before the sixth session (T2; 48-72 h after the fifth session). Age- and sex-matched controls (N = 99) were recruited from the general population. Serum concentrations of neurofilament light chain (NfL), total tau protein, and glial fibrillary acidic protein (GFAP) were measured with ultrasensitive single-molecule array assays. Utilizing generalized least squares regression, we compared baseline (T0) biomarker concentrations against those of our control group, and calculated the shifts in serum biomarker concentrations from baseline to immediately post-first ECT session (T1), and prior to the sixth session (T2). Baseline analysis revealed that serum levels of NfL (p < 0.001) and tau (p = 0.036) were significantly elevated in ECT recipients compared with controls, whereas GFAP levels showed no significant difference. Relative to T0, serum NfL concentration neither changed at T1 (mean change 3.1%, 95%CI -0.5% to 6.7%, p = 0.088) nor at T2 (mean change -3.2%, 95%CI -7.6% to 1.5%, p = 0.18). Similarly, no change in total tau was observed (mean change 3.7%, 95%CI -11.6% to 21.7%, p = 0.65). GFAP increased from T0 to T1 (mean change 20.3%, 95%CI 14.6 to 26.3%, p < 0.001), but not from T0 to T2 (mean change -0.7%, 95%CI -5.8% to 4.8%, p = 0.82). In conclusion, our findings suggest that ECT induces a temporary increase in serum GFAP, possibly reflecting transient astrocytic activation. Importantly, we observed no indicators of neuronal damage or long-term elevation in any assessed biomarker.

Electroconvulsive therapy-specific volume changes in nuclei of the amygdala and their relationship to long-term anxiety improvement in depression

Electroconvulsive therapy (ECT) is one of the most effective treatments for depression. ECT induces volume changes in the amygdala, a key center of anxiety. However, the clinical relevance of ECT-induced changes in amygdala volume remains uncertain. We hypothesized that nuclei-specific amygdala volumes and anxiety symptoms in depression could explain the clinical correlates of ECT-induced volume changes. To test this hypothesis, we enrolled patients with depression who underwent ECT (N = 20) in this multicenter observational study and collected MRI data at three time points: before and after treatment and a 6-month follow-up. Patients who received medication (N = 52), cognitive behavioral therapy (N = 63), or transcranial magnetic stimulation (N = 20), and healthy participants (N = 147) were included for comparison. Amygdala nuclei were identified using FreeSurfer and clustered into three subdivisions to enhance reliability and interpretability. Anxiety symptoms were quantified using the anxiety factor scores derived from the Hamilton Depression Rating Scale. Before treatment, basolateral and basomedial subdivisions of the right amygdala were smaller than those of healthy controls. The volumes of the amygdala subdivisions increased after ECT and decreased during the follow-up period, but the volumes at 6-month follow-up were larger than those observed before treatment. These volume changes were specific to ECT. Long-term volume changes in the right basomedial amygdala correlated with improvements in anxiety symptoms. Baseline volumes in the right basolateral amygdala correlated with long-term improvements in anxiety symptoms. These findings demonstrate that clinical correlates of ECT-induced amygdala volume changes are existent, but in a nucleus and symptom-specific manner.

Effects of electroconvulsive shock on the function, circuitry, and transcriptome of dentate gyrus granule neurons

Therapeutic use of electroconvulsive shock (ECS) is particularly effective for treatment-resistant depression. Like other more common forms of antidepressant treatment such as SSRIs, ECS has been shown to increase neurogenesis in the hippocampal dentate gyrus of rodent models. Yet the question of how ECS-induced neurogenesis supports improvement of depressive symptoms remains unknown. Here, we show that ECS-induced neurogenesis is necessary to improve depressive-like behavior of mice exposed to chronic corticosterone (Cort). We then use slice electrophysiology to show that optogenetic stimulation of adult-born neurons produces a greater hyperpolarization in mature granule neurons after ECS vs Sham treatment. We identify that this hyperpolarization requires the activation of group II metabotropic glutamate receptors. Consistent with this finding, we observe reduced expression of the immediate early gene cFos in the granule cell layer of ECS vs Sham subjects. Using single nucleus RNA sequencing, we reveal major transcriptomic shifts in granule neurons after treatment with ECS+Cort or fluoxetine+Cort vs Cort alone. We identify a population of immature cells which has greater representation in both ECS+Cort and fluoxetine+Cort treated samples vs Cort alone. We also find global differences in ECS-vs fluoxetine-induced transcriptomic shifts. Together, these findings highlight a critical role for immature granule cells in the antidepressant action of ECS.

Characterization of gray matter volume changes from one week to 6 months after termination of electroconvulsive therapy in depressed patients

BACKGROUND

Increased gray matter volume (GMV) following electroconvulsive therapy (ECT) has been well-documented, with limited studies reporting a subsequent decrease in GMV afterwards.

OBJECTIVE

This study characterized the reversion pattern of GMV after ECT and its association with clinical depression outcome, using multi-site triple time-point data from the Global ECT-MRI Research Collaboration (GEMRIC).

METHODS

86 subjects from the GEMRIC database were included, and GMV in 84 regions-of-interest (ROI) was obtained from automatic segmentation of T1 MRI images at three timepoints: pre-ECT (T0), within one-week post-ECT (T1), and one to six months post-ECT (T2). RM-ANOVAs were used to assess longitudinal changes and LMM analyses explored associations between GMV changes and demographical and clinical characteristics.

RESULTS

63 of the 84 ROIs showed a significant increase-and-decrease pattern (RM-ANOVA, Bonferroni corrected p < 0.00059). Post hoc tests indicated a consistent pattern in each of these 63 ROIs: significant increase from T0 to T1inGMV, followed by significant decrease from T1 to T2 and no difference between T0 and T2, except for both amygdalae, right hippocampus and pars triangularis, which showed the same increase and decrease but GMV at T2 remained higher compared to T0. No consistent relationship was found between GMV change pattern and clinical status.

CONCLUSION

The GEMRIC cohort confirmed a rapid increase of GMV after ECT followed by reversion of GMV one to six months thereafter. The lack of association between the GMV change pattern and depression outcome scores implies a transient neurobiological effect of ECT unrelated to clinical improvement.

What Is Brain Damage and Does Electroconvulsive Therapy Cause It?

ABSTRACT

Surveys show public misperceptions and confusion about brain damage and electroconvulsive therapy (ECT). Fictional movies have misrepresented ECT to suggest brain damage and to ridicule mental illness and psychiatric patients. "Brain damage" has become a colloquial expression without consistent meaning. In contrast, brain injury is the medical term for destruction of brain cells, such as from kinetic impact (concussion), hypoxia, or infection. Studies of both high-resolution magnetic resonance imaging (MRI) and enzyme assays find that causes of brain injury are accompanied by observable structural changes on MRI and elevated blood and cerebrospinal fluid levels of brain enzymes that leak from injured brain cells. Concussion is also followed by intracerebral bleeding, progressive brain atrophy, diffuse axonal injury, cranial nerve injury, and 2-4 fold increased risk for dementia. In contrast, there is no evidence that ECT produces any of these. Studies of ECT patients find no brain edema, structural change persisting 6 months, or elevated levels of leaked brain enzymes. Statistical comparisons between brain injury and ECT effects indicate no similarity ( P < 0.00000001). Moreover, the kinetic, thermal, and electrical effects of ECT are far below levels that could possibly cause harm. This robust evidence shows that there is no basis to claim that ECT causes brain injury.

GPR55 activation improves anxiety- and depression-like behaviors of mice during methamphetamine withdrawal

Methamphetamine is a potent and highly addictive neurotoxic psychostimulant that triggers a spectrum of adverse emotional responses during withdrawal. G-protein coupled receptor 55 (GPR55), a novel endocannabinoid receptor, is closely associated with mood regulation. Herein, we developed a murine model of methamphetamine-induced anxiety- and depressive-like behavior during abstinence which showed a decreased GPR55 expression in the hippocampus. Activation of GPR55 mitigated these behavioral symptoms, concomitantly ameliorating impairments in hippocampal neurogenesis and reducing neuroinflammation. These findings underscore the pivotal role of GPR55 in mediating the neuropsychological consequences of methamphetamine withdrawal, potentially via mechanisms involving the modulation of hippocampal neurogenesis and inflammation.