Electroconvulsive therapy-induced volumetric brain changes converge on a common causal circuit in depression.

Neurostimulation is a mainstream treatment option for major depression. Neuromodulation techniques apply repetitive magnetic or electrical stimulation to some neural target but significantly differ in their invasiveness, spatial selectivity, mechanism of action, and efficacy. Despite these differences, recent analyses of transcranial magnetic stimulation (TMS) and deep brain stimulation (DBS)-treated individuals converged on a common neural network that might have a causal role in treatment response. We set out to investigate if the neuronal underpinnings of electroconvulsive therapy (ECT) are similarly associated with this causal depression network (CDN). Our aim here is to provide a comprehensive analysis in three cohorts of patients segregated by electrode placement (N = 246 with right unilateral, 79 with bitemporal, and 61 with mixed) who underwent ECT. We conducted a data-driven, unsupervised multivariate neuroimaging analysis Principal Component Analysis (PCA) of the cortical and subcortical volume changes and electric field (EF) distribution to explore changes within the CDN associated with antidepressant outcomes. Despite the different treatment modalities (ECT vs TMS and DBS) and methodological approaches (structural vs functional networks), we found a highly similar pattern of change within the CDN in the three cohorts of patients (spatial similarity across 85 regions: r = 0.65, 0.58, 0.40, df = 83). Most importantly, the expression of this pattern correlated with clinical outcomes (t = -2.35, p = 0.019). This evidence further supports that treatment interventions converge on a CDN in depression. Optimizing modulation of this network could serve to improve the outcome of neurostimulation in depression.

A mood state-specific interaction between kynurenine metabolism and inflammation is present in bipolar disorder.

OBJECTIVES: Cytokines are thought to contribute to the pathogenesis of psychiatric symptoms by kynurenine pathway activation. Kynurenine metabolites affect neurotransmission and can cause neurotoxicity. We measured inflammatory markers in patients with bipolar disorder (BD) and studied their relation to kynurenine metabolites and mood. METHODS: Patients with BD suffering from an acute mood episode were assigned to the depressive (n = 35) or (hypo)manic (n = 32) subgroup. Plasma levels of inflammatory markers [cytokines, C-reactive protein] and kynurenine metabolites [tryptophan (TRP), kynurenine (KYN), 3-hydroxykynurenine (3-HK), quinolinic acid (QA), kynurenic acid (KYNA)] were measured on 6 time points during 8 months follow-up. Biological marker levels in patients were compared to controls (n = 35) and correlated to scores on mood scales. Spearman correlations and linear mixed models were used for statistical analysis. RESULTS: Twenty patients of the manic subgroup, 29 of the depressive subgroup, and 30 controls completed the study. The manic subgroup had a rapid remission of mood symptoms, but in the depressive subgroup subsyndromal symptoms persisted. No differences in inflammation were found between groups. A strong correlation between tumor necrosis factor-α and KYN, KYN/TRP, 3-HK and QA (ρ > 0.60) was specific for the manic group, but only at baseline (during mania). The depressive subgroup had a lower neuroprotective ratio (KYNA/3-HK, P = .0004) and a strong association between interferon-y and kynurenine pathway activation (P < .0001). KYNA was low in both patient groups versus controls throughout the whole follow-up (P = .0008). CONCLUSIONS: Mania and chronic depressive symptoms in BD are accompanied by a strong interaction between inflammation and a potentially neurotoxic kynurenine metabolism.

Inflammation, Hippocampal Volume, and Therapeutic Outcome following Electroconvulsive Therapy in Depressive Patients: A Pilot Study.

INTRODUCTION: Electroconvulsive therapy (ECT) influences the concentration of peripheral inflammatory markers, such as interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). In which way this immune effect contributes to the impact of ECT on the central nervous system in depression remains unknown. OBJECTIVE: The aim of this study was to examine whether the hippocampal volumetric increase in depressed patients treated with ECT is related to changes in peripheral IL-6 and TNF-α levels. METHODS: IL-6 and TNF-α plasma levels were measured in 62 patients 1 week before and after an acute course of ECT. Hippocampal volumes were analyzed in a magnetic resonance imaging (MRI) subsample of 13 patients at the same time points. RESULTS: A significant decrease in IL-6 levels was observed in the total sample and a significant increase in hippocampal volume in the MRI subsample. The reduction of peripheral IL-6 correlated with an increase in total hippocampal volume. A more limited decrease of TNF-α correlated with a more limited increase of both the total and left hippocampus volumes. CONCLUSION: This pilot study is the first to highlight the link between peripheral immune changes and hippocampal volume increase following ECT. Further research is required to conclude whether ECT indeed exerts its central effect on the brain via changes of peripheral inflammatory markers.

Cognitive Deficits in Older Adults With Psychotic Depression: A Meta-Analysis.

A major depressive disorder with psychotic features, that is, psychotic depression (PD), is often accompanied by cognitive deficits, particularly in older patients. We aimed to assess to what extent various cognitive domains are affected in older patients with PD compared to those with nonpsychotic depression (NPD). Therefore, a systematic search was conducted in Medline, Embase, Web of Science, the Cumulative Index to Nursing and Allied Literature (CINAHL), Google Scholar, and Cochrane for all relevant studies. Hereafter, we conducted a meta-analysis of seven studies on cognitive deficits in older adults (55+ years), comparing patients with PD and patients with NPD. Compared to patients with NPD, those with PD not only showed a significantly poorer performance on overall cognitive function, with a Hedges' g effect size of -0.34 (95% confidence interval: -0.56; -0.12; p = 0.003), but also on nearly all separate cognitive domains, with Hedges' g effect sizes ranging from -0.26 to -0.64 (all p's <0.003), of which attention was most adversely affected. Verbal fluency showed no significant effect, although this analysis may have been underpowered. The funnel plot suggested no significant publication bias (Egger test intercept: -2.47; 95% confidence interval: -5.50; 0.55; p = 0.09). We conclude that older patients with PD show more cognitive deficits on all cognitive domains, except for verbal fluency, compared to patients with NPD. It is crucial that clinicians and researchers take cognitive deficits into consideration in older adults with PD.

Performance of the Psychotic Depression Assessment Scale as a Predictor of ECT Outcome.

OBJECTIVES: The presence of psychotic symptoms is an important predictor of responsiveness to electroconvulsive therapy (ECT). This study investigates whether a continuous severity measure, the Psychotic Depression Assessment Scale (PDAS), is a more accurate predictor. METHODS: Depression severity was assessed before and after the ECT course using the Montgomery-Asberg Depression Rating Scale (MADRS) in 31 patients with psychotic depression and 34 depressed patients without psychotic symptoms. Logistic regression models for MADRS response and remission were fitted, with either the PDAS total score or the dichotomous predictors "absence/presence of psychotic symptoms" as the independent variables. Age, episode duration, and treatment resistance were added as covariates. RESULTS: Both the asserted presence of psychotic symptoms and a higher PDAS total score reflected MADRS response (areas under the curve, 0.83 and 0.85, respectively), with MADRS remission also being predicted by the presence of psychotic symptoms and higher PDAS scores (areas under the curves, 0.86 and 0.84, respectively). Age was a contributor to these prediction models, with response and remission rates being highest in the older patients. Psychotic Depression Assessment Scale scores decreased significantly during ECT: at end point, 81.5% of the patients showed significant response and 63.9% had achieved remission. CONCLUSIONS: The PDAS indeed accurately predicts response to and remission after ECT in (psychotic) depression and most pronouncedly so in older patients but seems to have no clear advantage over simply verifying the presence of psychotic symptoms. This could be the consequence of a ceiling effect, as ECT was extremely effective in patients with psychotic depression.ClinicalTrials.gov: Identifier: NCT02562846.

Prediction of electroconvulsive therapy response and remission in major depression: meta-analysis.

BACKGROUND: Electroconvulsive therapy (ECT) is considered to be the most effective treatment in severe major depression. The identification of reliable predictors of ECT response could contribute to a more targeted patient selection and consequently increased ECT response rates. Aims To investigate the predictive value of age, depression severity, psychotic and melancholic features for ECT response and remission in major depression. METHOD: A meta-analysis was conducted according to the PRISMA statement. A literature search identified recent studies that reported on at least one of the potential predictors. RESULTS: Of the 2193 articles screened, 34 have been included for meta-analysis. Presence of psychotic features is a predictor of ECT remission (odds ratio (OR) = 1.47, P = 0.001) and response (OR = 1.69, P < 0.001), as is older age (standardised mean difference (SMD) = 0.26 for remission and 0.35 for response (P < 0.001)). The severity of depression predicts response (SMD = 0.19, P = 0.001), but not remission. Data on melancholic symptoms were inconclusive. CONCLUSIONS: ECT is particularly effective in patients with depression with psychotic features and in elderly people with depression. More research on both biological and clinical predictors is needed to further evaluate the position of ECT in treatment protocols for major depression. Declaration of interest None.

Prediction of Electroconvulsive Therapy Response and Remission in Major Depression: Meta-analysis - CORRIGENDUM.

This notice describes a correction to the above mentioned paper.

The Maudsley Staging Method as predictor of electroconvulsive therapy effectiveness in depression.

OBJECTIVE: To investigate the potential role of the Maudsley Staging Method (MSM) in the prediction of electroconvulsive therapy (ECT) outcome in severely depressed adults. METHOD: Between August 2015 and August 2017, 73 consecutive patients with a major depressive episode (DSM-IV-TR) scheduled for ECT were recruited. Prior to their first ECT session, the MSM was completed to assess the level of therapy resistance. To determine the reduction in depression severity and response and remission rates, symptom severity was assessed at baseline and within one week after the last ECT session using the 17-item Hamilton Depression Rating Scale (HDRS17). RESULTS: The percentage of symptom reduction following ECT was best predicted by the MSM episode duration and depression severity factors (R2 completer sample 0.24). Episode duration alone was the best predictor of remission (area under the ROC curve for completers: 0.72). Adding age to the models increased their predictive capacity. CONCLUSION: An adapted version of the MSM gauging shorter episode duration, more severe depressive symptoms and older age is significantly associated with ECT effectiveness in adults with severe recurrent depression and is thus highly suitable for use in clinical practice, promoting the shared treatment decision-making process.

Observer-rated retardation but not agitation corresponds to objective motor measures in depression.

OBJECTIVE: To explore the correlations between observer ratings and instrumental parameters across domains of psychomotor functioning in depression. METHOD: In total, 73 patients with major depressive disorder underwent extensive psychomotor and clinical testing. Psychomotor functioning was assessed with (i) an observer-rated scale (the CORE measure) and also objectively with (ii) 24-h actigraphy, and (iii) a fine motor drawing task. RESULTS: Observer ratings of retardation correlated with instrumental assessments of fine and gross motor functioning. In contrast, observer ratings of agitation did not correlate with observer ratings of retardation or with the instrumental measures. These associations were partly influenced by age and, to a lesser extent, by depression severity. CONCLUSION: Psychomotor disturbance is a complex concept with different manifestations in depressed patients. Although observer ratings of retardation correspond well with instrumental measures of the motor domains, objective measurement of agitation and other aspects of psychomotor disturbance require further research.

Clinical validation of the Psychotic Depression Assessment Scale (PDAS) against independent global severity ratings in older adults.

OBJECTIVES: According to a recent study, ratings on the Psychotic Depression Assessment Scale (PDAS) obtained via a dedicated semi-structured interview are valid measures of the severity of psychotic depression. This study aimed to further test the validity, scalability and responsiveness of the PDAS in older adults using independent ratings on the Clinical Global Impression Scale - Severity (CGI-S) and the Montgomery-Asberg Depression Rating Scale (MADRS) as references. METHODS: Ratings were performed at admission and discharge at two old age psychiatric wards in Flanders, Belgium. In total, 62 older adults (mean age: 74.3 years) with psychotic depression were included. The PDAS was rated by trained nurses using the semi-structured PDAS interview. Senior psychiatrists scored the participants on the CGI-S. Psychologists or experienced nurses rated participants on the MADRS. Clinical validity was assessed by correlating the PDAS total scores with CGI-S ratings and MADRS total scores. Mokken analysis was performed to assess the scalability of the PDAS. Responsiveness was assessed by comparing the proportion of participants in remission (PDAS total score <8 at study baseline and endpoint). RESULTS: The Spearman correlation coefficients were 0.76 and 0.79 for the PDAS versus CGI-S and PDAS versus MADRS, respectively. The Mokken analysis yielded a Loevinger coefficient of 0.46, which is indicative of scalability. At admission, no participants met the PDAS remission criterion. At discharge, 54% (95% confidence interval: 47%-60%) of the patients met this criterion. CONCLUSION: The PDAS appears to be a clinically valid, scalable and responsive measure of the severity of psychotic depression in older adults.

Distinguishing Subgroups Based on Psychomotor Functioning among Patients with Major Depressive Disorder.

BACKGROUND: Retardation and agitation are symptoms of major depressive disorder (MDD), and their presence could play a role in determining clinically meaningful depressive subtypes such as nonmelancholic depression (NMD) and melancholic depression (MD). In this project, we explored whether three depression subgroups (NMD, MD with psychotic symptoms, and MD without psychotic symptoms) could be distinguished based on objective measures of psychomotor functioning. METHODS: Sixty-nine patients with MDD underwent extensive clinical and psychomotor testing prior to treatment with electroconvulsive therapy. Psychomotor functioning was assessed subjectively using the Core Assessment of Psychomotor Change (CORE) and objectively by means of both 24-h actigraphy and performance on a fine motor drawing task. RESULTS: The daytime activity levels measured by actigraphy were significantly lower (F = 7.1, p = 0.0004) in MD patients both with and without psychotic symptoms than in those with NMD. No objective psychomotor variable was able to distinguish between melancholic patients with and those without psychotic symptoms. CONCLUSIONS: The depression subtypes NMD, MD with psychotic symptoms, and MD without psychotic symptoms are not marked by increasing psychomotor retardation, possibly because psychomotor disturbance in MD with psychotic symptoms often consists of agitation rather than retardation, or a mixture of the two. However, psychomotor functioning as measured by actigraphy can be used to distinguish between NMD patients and MD patients.

The impact of need-based care on formal caregivers' wellbeing in nursing homes: A cluster randomized controlled trial.

BACKGROUND: Need-based care is a structured and standardized model that supports formal caregivers in nursing homes in delivering person-centered care by responding with tailored non-pharmacological interventions on residents' unmet needs as well as having positive effects on behavioral and psychological symptoms on residents with dementia. However, limited resources as well as the shortage of caregivers in nursing homes make the implementation of need-based care challenging, especially when it comes to finding ways to spend more time with residents. The aim of this study is to evaluate the impact of the implementation of need-based care in nursing homes on formal caregivers' wellbeing. METHODS: A three-arm cluster randomized controlled trial was set up in 24 Belgian nursing homes: formal caregivers in the 'need-based care' group (intervention; n = 195) spent time twice a week with residents who had behavioral and psychological symptoms according to the principles of need-based care while formal caregivers in the 'time' group (n = 257) filled in the way they spent time twice a week; a third group delivered standard care (n = 299). An implementation strategy was built upon the Implementation Quality Framework and used in the 'need-based care group'. A total of 741 formal caregivers completed the digital questionnaire at one or more of the five time points (every nine weeks) between November 2021 and July 2022; they rated their sense of competence in dementia care, level of burnout, and, level of engagement. Moments of time were registered in a printed registration book. RESULTS: Only formal caregivers from the 'need-based care' group experienced a higher sense of competence in dementia care at time points three (p = 0.010) and four (p = 0.001) compared with baseline with an increase of respectively 1.5 (95 % confidence interval [0.25, 2.84]) and 2.4 (95 % confidence interval [0.77, 4.04]) points. No differences in scores on burnout and engagement were found. CONCLUSION: Despite challenging workforce circumstances in nursing homes, caregivers in the need-based care group as well as in the time group were able to spend time twice a week with residents with behavioral and psychological symptoms. No negative effects were found on formal caregivers' wellbeing after the implementation of need-based care in nursing homes. However, it requires strong leadership and the use of well-considered implementation strategies including reflective practice. TRIAL REGISTRY: Trial registration number ISRCTN56768265 (10/08/2023).

Effect of need-based care on behavioural and psychological symptoms in residents with dementia and formal caregivers' distress in nursing homes: a three-arm cluster randomized controlled trial.

PURPOSE: To evaluate to what extent the standardized concept of need-based care on Behavioural and Psychological Symptoms of Dementia (BPSD), and formal caregiver distress, is superior when compared to spending more time or standard care with residents with BPSD. METHODS: A longitudinal cluster randomized controlled study in 23 nursing homes in Belgium with 3 parallel groups was set up. A total of 481 residents with dementia participated. Formal caregivers in the need-based care group treated residents who displayed agitated or aggressive behaviour with a non-pharmacological intervention, tailored to unmet needs, twice a week with re-evaluation every 8 weeks. In the time group, formal caregivers spent 'extra time'. In the standard care group, it was 'care as usual'. Outcomes were measured at four different time points with the Doloplus-2 (to assess pain behaviour), Cohen-Mansfield Agitation Inventory (CMAI) for agitation, the Neuropsychiatric Inventory (NPI-NH) for BPSD and formal caregivers' distress. RESULTS: Need-based interventions had a significant effect on residents' levels of pain behaviour. In the need-based care group, scores on overall BPSD (agitation and aggression, depression, euphoria, irritability, sleep and night-time behaviour) improved significantly from baseline when compared to other timepoints. No significant different interactions over time were found between all three groups for categorized versions of NPI scores (ever versus never). CONCLUSION: Need-based care reduced the level of BPSD in residents with dementia as well as formal caregivers' distress. The study supports the importance of tailored non-pharmacological interventions in the residential care for people with dementia. TRIAL REGISTRY: Trial registration number B300201942084 (18/11/2019).

Reviewing the neurobiology of electroconvulsive therapy on a micro- meso- and macro-level.

BACKGROUND: Electroconvulsive therapy (ECT) remains the one of the most effective of biological antidepressant interventions. However, the exact neurobiological mechanisms underlying the efficacy of ECT remain unclear. A gap in the literature is the lack of multimodal research that attempts to integrate findings at different biological levels of analysis METHODS: We searched the PubMed database for relevant studies. We review biological studies of ECT in depression on a micro- (molecular), meso- (structural) and macro- (network) level. RESULTS: ECT impacts both peripheral and central inflammatory processes, triggers neuroplastic mechanisms and modulates large scale neural network connectivity. CONCLUSIONS: Integrating this vast body of existing evidence, we are tempted to speculate that ECT may have neuroplastic effects resulting in the modulation of connectivity between and among specific large-scale networks that are altered in depression. These effects could be mediated by the immunomodulatory properties of the treatment. A better understanding of the complex interactions between the micro-, meso- and macro- level might further specify the mechanisms of action of ECT.

Electroconvulsive therapy-induced volumetric brain changes converge on a common causal circuit in depression.

Neurostimulation is a mainstream treatment option for major depression. Neuromodulation techniques apply repetitive magnetic or electrical stimulation to some neural target but significantly differ in their invasiveness, spatial selectivity, mechanism of action, and efficacy. Despite these differences, recent analyses of transcranial magnetic stimulation (TMS) and deep brain stimulation (DBS)-treated individuals converged on a common neural network that might have a causal role in treatment response. We set out to investigate if the neuronal underpinnings of electroconvulsive therapy (ECT) are similarly associated with this common causal network (CCN). Our aim here is to provide a comprehensive analysis in three cohorts of patients segregated by electrode placement (N = 246 with right unilateral, 79 with bitemporal, and 61 with mixed) who underwent ECT. We conducted a data-driven, unsupervised multivariate neuroimaging analysis (Principal Component Analysis, PCA) of the cortical and subcortical volume changes and electric field (EF) distribution to explore changes within the CCN associated with antidepressant outcomes. Despite the different treatment modalities (ECT vs TMS and DBS) and methodological approaches (structural vs functional networks), we found a highly similar pattern of change within the CCN in the three cohorts of patients (spatial similarity across 85 regions: r = 0.65, 0.58, 0.40, df = 83). Most importantly, the expression of this pattern correlated with clinical outcomes. This evidence further supports that treatment interventions converge on a CCN in depression. Optimizing modulation of this network could serve to improve the outcome of neurostimulation in depression.

Cognitive trajectories during and after electroconvulsive therapy in patients with MDE: Taking different perspectives.

Cognitive function during an ECT care pathway is mainly investigated at the group level by analyzing mean cognitive test scores over time. However, there are important inter-individual differences, with some patients experiencing residual invalidating cognitive deficits. This study provides a nuanced examination of cognitive functioning during and after ECT by combining three approaches for data analysis. A cognitive test battery was assessed in seventy-three ECT-treated patients with a Major Depressive Episode (MDE) at up to five time points (baseline, immediately prior to the third session and 1 week, 3 months and 6 months after completion of the index course). Group-level changes in cognitive function were investigated using linear mixed models and individual-level changes were examined using Reliable Change Indices (RCI). The presence of patient subgroups with similar cognitive trajectories was explored using Latent Class Growth Analysis (LCGA). At the group level, there was a temporary deterioration in processing speed, verbal memory and retrograde amnesia during and after index course of ECT. Individual-level analyses revealed considerable variability in cognitive effects of ECT. Three patient classes with a similar cognitive trajectory could be identified, all with a rather parallel courses over time, thus mainly differing in terms of pre-ECT cognitive functioning.

White matter changes following electroconvulsive therapy for depression: a multicenter ComBat harmonization approach.

ECT is proposed to exert a therapeutic effect on WM microstructure, but the limited power of previous studies made it difficult to highlight consistent patterns of change in diffusion metrics. We initiated a multicenter analysis and sought to address whether changes in WM microstructure occur following ECT. Diffusion tensor imaging (DTI) data (n = 58) from 4 different sites were harmonized before pooling them by using ComBat, a batch-effect correction tool that removes inter-site technical variability, preserves inter-site biological variability, and maximizes statistical power. Downstream statistical analyses aimed to quantify changes in Fractional Anisotropy (FA), Mean Diffusivity (MD), Radial Diffusivity (RD) and Axial Diffusivity (AD), by employing whole-brain, tract-based spatial statistics (TBSS). ECT increased FA in the right splenium of the corpus callosum and the left cortico-spinal tract. AD in the left superior longitudinal fasciculus and the right inferior fronto-occipital fasciculus was raised. Increases in MD and RD could be observed in overlapping white matter structures of both hemispheres. At baseline, responders showed significantly smaller FA values in the left forceps major and smaller AD values in the right uncinate fasciculus compared with non-responders. By harmonizing multicenter data, we demonstrate that ECT modulates altered WM microstructure in important brain circuits that are implicated in the pathophysiology of depression. Furthermore, responders appear to present a more decreased WM integrity at baseline which could point toward a specific subtype of patients, characterized by a more altered neuroplasticity, who are especially sensitive to the potent neuroplastic effects of ECT.

Interrogating Associations Between Polygenic Liabilities and Electroconvulsive Therapy Effectiveness.

BACKGROUND: Electroconvulsive therapy (ECT) is the most effective treatment for severe major depressive episodes (MDEs). Nonetheless, firmly established associations between ECT outcomes and biological variables are currently lacking. Polygenic risk scores (PRSs) carry clinical potential, but associations with treatment response in psychiatry are seldom reported. Here, we examined whether PRSs for major depressive disorder, schizophrenia (SCZ), cross-disorder, and pharmacological antidepressant response are associated with ECT effectiveness. METHODS: A total of 288 patients with MDE from 3 countries were included. The main outcome was a change in the 17-item Hamilton Depression Rating Scale scores from before to after ECT treatment. Secondary outcomes were response and remission. Regression analyses with PRSs as independent variables and several covariates were performed. Explained variance (R2) at the optimal p-value threshold is reported. RESULTS: In the 266 subjects passing quality control, the PRS-SCZ was positively associated with a larger Hamilton Depression Rating Scale decrease in linear regression (optimal p-value threshold = .05, R2 = 6.94%, p < .0001), which was consistent across countries: Ireland (R2 = 8.18%, p = .0013), Belgium (R2 = 6.83%, p = .016), and the Netherlands (R2 = 7.92%, p = .0077). The PRS-SCZ was also positively associated with remission (R2 = 4.63%, p = .0018). Sensitivity and subgroup analyses, including in MDE without psychotic features (R2 = 4.42%, p = .0024) and unipolar MDE only (R2 = 9.08%, p < .0001), confirmed the results. The other PRSs were not associated with a change in the Hamilton Depression Rating Scale score at the predefined Bonferroni-corrected significance threshold. CONCLUSIONS: A linear association between PRS-SCZ and ECT outcome was uncovered. Although it is too early to adopt PRSs in ECT clinical decision making, these findings strengthen the positioning of PRS-SCZ as relevant to treatment response in psychiatry.

Improvement of psychomotor retardation after electroconvulsive therapy is related to decreased IL-6 levels.

BACKGROUND: Prior studies suggest that IL-6 may be involved in the pathophysiology of psychomotor symptoms in depression. Electroconvulsive therapy (ECT), as yet the most effective biological treatment of severe depression, is known to improve psychomotor functioning, while recent studies have shown a decrease in the elevated IL-6 levels of depressed patients following ECT. OBJECTIVES: This study investigates whether the improvement in psychomotor functions in patients with depression after ECT is related to changes in IL-6 levels. METHODS: Peripheral IL-6 was quantified and the severity of psychomotor agitation and retardation determined using the CORE assessment of psychomotor symptoms in 62 patients with a (unipolar or bipolar) depressive episode within one week before and within one week after their course of ECT. RESULTS: IL-6 levels had decreased significantly following ECT and both psychomotor retardation and agitation had improved. The decrease in IL-6 levels was related to the improvement of psychomotor retardation, with post-hoc analysis revealing that higher baseline IL-6 levels positively correlated with higher psychomotor retardation scores. CONCLUSION: With this study, we provide the first evidence that the improvement of psychomotor retardation after ECT for depression is related to the immunomodulatory properties of the treatment, most specifically the decrease in IL-6 levels.