A resting state EEG study on depressed persons with suicidal ideation

Meta analysis of resting frontal alpha asymmetry as a biomarker of depression

This meta-analysis investigated resting frontal alpha asymmetry (FAA) as a potential biomarker for major depressive disorder (MDD). Studies included articles utilizing FAA measure involving EEG electrodes (F3/F4, F7/F8, or Fp1/Fp2) and covering both MDD and controls. Hedges' d was calculated from FAA means and standard deviations (SDs). A systematic search of PubMed through July 2023 identified 23 studies involving 1928 MDD participants and 2604 controls. The analysis revealed a small but significant grand mean effect size (ES) for FAA (F4 - F3), suggesting limited diagnostic value of FAA in MDD. Despite the presence of high heterogeneity across studies, subgroup analyses did not identify significant differences based on calculation formula, reference montage, age, or depression severity. The findings indicate that FAA may have limited standalone diagnostic utility but could complement existing clinical assessments for MDD, highlighting the need for a multifaceted approach to depression diagnosis and prognosis.

Association of resting-state EEG with suicidality in depressed patients: a systematic review

OBJECTIVE

The incidence of suicide is high among adolescents and young adults, especially those suffering from psychiatric diseases. Because of the reported association between depression and suicidality, exploring suicide risk factors in depressed patients is crucial for the identification of those at high risk and preventing suicide. In recent decades, electroencephalography parameters have been considered for identifying biomarkers of suicide ideation and attempts in depressed patients. This study aimed to review the available literature on resting-state EEG for suicidality in depressed patients.

METHOD

A systematic search was performed in five electronic databases, including APA PsycINFO, Embase, Medline (via PubMed), Scopus, and Web of Science. Papers with full text available in English in which resting-state EEG was evaluated in depressed patients with suicide ideation or suicide attempts compared to a control group of healthy subjects or non-suicidal depressed patients were included. The risk of bias was assessed by using the Newcastle-Ottawa scale.

RESULTS

A total of 4665 references were retrieved from five electronic databases from which eleven studies were included in this systematic review. A meta-analysis was not performed due to the substantial heterogeneity of the studies. Five of the eleven reviewed papers were classified as high-quality, and six had moderate quality.

CONCLUSIONS

According to the included studies in this review, the EEG signals of depressed patients with suicide ideation or suicide attempts may be different from patients with low risk of suicidality or healthy subjects. Connectivity measures sound more promising parameters than the power spectral analysis and EEG asymmetry.

PROTOCOL REGISTRATION

The protocol of this review was registered in PROSPERO (No. CRD42024502056).

Resting-state EEG features modulated by depressive state in healthy individuals: insights from theta PSD, theta-beta ratio, frontal-parietal PLV, and sLORETA

Depressive states in both healthy individuals and those with major depressive disorder exhibit differences primarily in symptom severity rather than symptom type, suggesting that there is a spectrum of depressive symptoms. The increasing prevalence of mild depression carries lifelong implications, emphasizing its clinical and social significance, which parallels that of moderate depression. Early intervention and psychotherapy have shown effective outcomes in subthreshold depression. Electroencephalography serves as a non-invasive, powerful tool in depression research, with many studies employing it to discover biomarkers and explore underlying mechanisms for the identification and diagnosis of depression. However, the efficacy of these biomarkers in distinguishing various depressive states in healthy individuals and in understanding the associated mechanisms remains uncertain. In our study, we examined the power spectrum density and the region-based phase-locking value in healthy individuals with various depressive states during their resting state. We found significant differences in neural activity, even among healthy individuals. Participants were categorized into high, middle, and low depressive state groups based on their response to a questionnaire, and eyes-open resting-state electroencephalography was conducted. We observed significant differences among the different depressive state groups in theta- and beta-band power, as well as correlations in the theta-beta ratio in the frontal lobe and phase-locking connections in the frontal, parietal, and temporal lobes. Standardized low-resolution electromagnetic tomography analysis for source localization comparing the differences in resting-state networks among the three depressive state groups showed significant differences in the frontal and temporal lobes. We anticipate that our study will contribute to the development of effective biomarkers for the early detection and prevention of depression.

[Validation of screening method based on EEG analysis for the risk assessment of psychiatric and behavioral disorders: a pilot study]

OBJECTIVE

To assess the validity of the screening method based on EEG analysis using predictive analytics algorithms with the calculation of linear discriminant functions (LDFs), in comparison with a classification system based on psychometric self-report scales.

MATERIAL AND METHODS

A comparative cross-sectional study with partial blinding involving healthy volunteers was conducted at two investigational sites. The calculated scores of LDFs used to assess risks of impulsivity, depression and anxiety acted as quantitative characteristics of subjects' mental state. Testing included completing psychometric scales.

RESULTS

As a result of the performed validation of the original screening method based on EEG analysis in comparison with the scores of psychometric scales chosen as a reference method, satisfactory results were obtained with the best parameters of sensitivity, specificity, and accuracy for detecting high levels of impulsivity associated with pronounced aggressiveness. Of considerable interest is also the direct correlation found between high levels of LDF impulsivity scores and high levels of self-rated aggression on a psychometric scale (BPAQ-24).

CONCLUSION

The results open up the possibility of using the proposed method to predict a number of emotional and behavioral characteristics of subjects, including a high risk of aggressive behavior as part of professional selection.

[EEG correlates of suicidal intentions in depressive patients who survived and have not been ill with COVID-19]

OBJECTIVE

To search for EEG correlates of suicidal intentions in young depressive patients who survived and have not been ill with COVID-19.

MATERIAL AND METHODS

We studied 46 female patients, aged 16-25 years, with depressive disorders who had previously had a mild or asymptomatic coronavirus infection («COVID» group) and 40 female patients with depressive disorders matched in age, syndromic structure of disorders and the initial severity of depression to patients of the «COVID» group but who are known not to have COVID-19 («non-COVID» group). The severity of suicidal intentions was assessed by the number of points of item 3 of HDRS-17. In all patients, pre-treatment multichannel background EEG was recorded with spectral power analysis in narrow frequency sub-bands.

RESULTS

In patients of the «COVID» group, the mean number of points of item 3 of HDRS-17 was slightly higher (at the trend level) than in the «non-COVID» group (2.1±1.5 and 1.8±1.6 points, respectively), and positively correlated (p<0.05) with the spectral power values of theta2 (6-8 Hz) and delta (2-4 Hz) EEG sub-bands. In the «non-COVID» group, the severity of suicidal intentions positively correlated (p<0.05) with the values of the spectral power of alpha2 (9-11 Hz) EEG sub-band.

CONCLUSION

Suicidal intentions increased in depressive patients survived from COVID-19, and their severity is associated with EEG signs of a reduced functional state of the cerebral cortex.