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).