Background: Non-suicidal self-injuring behavior (NSSI) is widespread  among adolescents, and is  one of important risk factors for suicide. The aim of the study was to identify features of decision-making and of EEG in female depressive adolescents with NSSI. Material and Methods: The study included 30 female depressive patients aged 16-25 years (mean age 18.9 ± 2.9 years) with NSSI in the form of multiple repeated self-cuts of inner surfaces of forearms and/or front surfaces hips. Clinical condition of patients was quantified using HDRS-17 scale. The control group included 16 depressive patients of the same gender, age, and severity of depression, but without NSSI. Pre-treatment background EEG spectral power was calculated in 8 narrow frequency sub-bands.  Wisconsin Card Sorting Test (WCST) and  Iowa Gambling Task (IGT) were used to evaluate decision-making functions. Descriptive statistics and correlation analysis were used. Results and discussion: The only intergroup difference in WCST and IGT tests was faster execution of  both tests by NSSI patients, that testified their faster decision-making. NSSI patients had left hemispheric accent of of alpha2 (9-11 Hz), alpha1 (8-9 Hz), theta2 (6-8 Hz) and delta (2-4 Hz) spectral power. They also had generalized bilaterally synchronous bursts of EEG theta activity.  Conclusions: EEG data obtained indicate the role of  reduced functional state of  anterior parts of the left hemisphere of cortex, which are responsible for voluntary control of activity and emotions, increased excitability of diencephalic brain structures mediating increased impulsivity, and a more relatively higher level of activation of the temporal regions of the right hemisphere associated with the control of negative emotions, in the manifestations of NSSI  in depressive adolescent patients.

The study was supported by RFBR grant No. 20-013-00129a.