Electroencephalographic Parameters Differentiating Melancholic Depression, Non-melancholic Depression, and Healthy Controls. A Systematic Review

Abstract

Introduction: The objective of this systematic review was to investigate whether electroencephalographic parameters can serve as a tool to distinguish between melancholic depression, non-melancholic depression, and healthy controls in adults.Methods: A systematic review comprising an extensive literature search conducted in PubMed, Embase, Google Scholar, and PsycINFO in August 2020 with monthly updates until November 1st, 2020. In addition, we performed a citation search and scanned reference lists. Clinical trials that performed an EEG-based examination on an adult patient group diagnosed with melancholic unipolar depression and compared with a control group of non-melancholic unipolar depression and/or healthy controls were eligible. Risk of bias was assessed by the Strengthening of Reporting of Observational Studies in Epidemiology (STROBE) checklist.Results: A total of 24 studies, all case-control design, met the inclusion criteria and could be divided into three subgroups: Resting state studies (n = 5), sleep EEG studies (n = 10), and event-related potentials (ERP) studies (n = 9). Within each subgroup, studies were characterized by marked variability on almost all levels, preventing pooling of data, and many studies were subject to weighty methodological problems. However, the main part of the studies identified one or several EEG parameters that differentiated the groups.Conclusions: Multiple EEG modalities showed an ability to distinguish melancholic patients from non-melancholic patients and/or healthy controls. The considerable heterogeneity across studies and the frequent methodological difficulties at the individual study level were the main limitations to this work. Also, the underlying premise of shifting diagnostic paradigms may have resulted in an inhomogeneous patient population.Systematic Review Registration: Registered in the PROSPERO registry on August 8th, 2020, registration number CRD42020197472.

Resting-state frontal, frontlateral, and parietal alpha asymmetry:A pilot study examining relations with depressive disorder type and severity

“…Given the known heterogeneity of depression and the issues raised in differential diagnosis ( Ghaemi and Vöhringer, 2011 ; Fried, 2017 ; Lorenzo-Luaces et al, 2021 ), reliable objective criteria such as electroencephalography (EEG) indices would have been helpful in detecting and differentiating depressive states. Currently, there is no consensus in the meta-analytic literature regarding the discriminative power of EEG asymmetry in depression, or in symptoms associated with depression, some highlighting the marker’s ability to discriminate ( Bruun et al, 2021 ), while others concluding inconsistencies, based on existing evidence ( van der Vinne et al, 2017 ; Kaiser et al, 2018 ; Kołodziej et al, 2021 ).…”

Psychiatric comorbidity in patients with pediatric bipolar disorder – A systematic review

“…Afterwards the individual ratings were compared, and any controversy was discussed with a third author (LVK). The STROBE scores were divided into percentages with ≤33% points reflecting low study quality, 33%–66% reflecting moderate study quality and ≥66% reflecting high study quality in accordance with prior procedures 20 …”

“…The STROBE scores were divided into percentages with ≤33% points reflecting low study quality, 33%-66% reflecting moderate study quality and ≥66% reflecting high study quality in accordance with prior procedures. 20…”

Depression Severity, Slow- versus Fast-Wave Neural Activity, and Symptoms of Melancholia

“…The search for neurobiological correlates of melancholia has included studies of the electrical activity of the brain [ 16 ], sometimes collected via an electroencephalograph (EEG) [ 17 ], which measures electrical activity at sites across the skull, enabling inferences to be drawn regarding brain activity under those sites. However, Bruun et al [ 17 ] found that some methodological limitations in much of the previous research on the neurobiological correlates of melancholia have left this issue yet to be comprehensively resolved.…”