EEG Asymmetries in Depressive Female Adolescents with Different Kinds of Auto-Aggressive Behavior

Abstract

Background: non-suicidal self-injury (NSSI) in adolescence is a significant risk factor for suicide, and therefore, the search for neurobiological markers and predictors of risk for suicidal intentions and actions seems to be an urgent task. In particular, quantitative EEG parameters can be such predictors.Objective: to identify the features of EEG in female adolescents with endogenous depressive conditions, manifested only by NSSI without suicidal intentions, in comparison with the EEG of patients who had suicidal auto-aggressive behavior (SAB) in the structure of depression.Patients and methods: the study was conducted as a comparative clinical and neurophysiological. The study included 45 female patients aged 16–25 years with endogenous depressive conditions, divided into 2 subgroups: those who showed only NSSI (NSSI subgroup, 21 patients), or who had a history of SAB (SAB subgroup, 24 patients). Clinical-psychopathological, psychometric, neurophysiological and statistical methods were used.Results and its discussion: intergroup differences were revealed in relation to the ratio and hemispheric asymmetry of the EEG spectral power of narrow frequency sub-bands of the parietal-occipital alpha rhythm. In the SAB subgroup alpha-2 (9–11 Hz) rhythm spectral power is higher than in the NSSI subgroup, the focus of alpha-2 spectral power is located in the right hemisphere, and alpha-3 sub-band (11–13 Hz) spectral power is higher than of alpha-1 (8–9 Hz). In the NSSI subgroup, alpha-1 (8–9 Hz) sub-band spectral power are higher than of alpha-3 (11–13 Hz), and focuses of alpha-2 (9–11 Hz) and alpha-3 (11–13 Hz) rhythms are localized in the left hemisphere. The results are discussed in terms of functional specialization of the brain hemispheres in relation to the regulation of emotions and control of behavior.Conclusions: the spatial distribution of the EEG frequency components in the SAB subgroup reflects the greater activation of the brain left hemisphere that is more typical for the EEG of individuals with an increased risk of suicide. In the NSSI subgroup, the right hemisphere is relatively more activated that is more typical for EEG in depressive disorders.The results obtained allow the use of quantitative EEG data to clarify the degree of suicidal risk in depressed female adolescents with non-suicidal self-injury.