Electroencephalographic differences in patients with paranoid schizophrenia with or without a history of suicide attempts

Abstract

To identify differences in electroencephalographic parameters in schizophrenia patients with and without a history of suicide attempts. Eighty-seven inpatients (50 men and 37 women) with paranoid schizophrenia were examined. Suicidal attempts in the anamnesis of patients were verified by a psychiatrist on the basis of clinical interviewing. The severity of psychopathological symptoms was assessed using The Positive and Negative Syndrome Scale (PANSS) based on a five-factor model. Electroencephalogram (EEG) parameters were recorded and evaluated using a 16-channel encephalograph. A clinical and quantitative analysis of the recordings was carried out with the calculation of absolute spectral power indicators for theta, alpha and beta rhythms, as well as the severity of the activation reaction (Berger effect). Significantly higher rates of the PANSS depression factor were revealed in patients with a history of suicide attempts (p=0.016). Clinical analysis of EEG changes did not reveal any significant differences between the groups (p>0.05). The spectral analysis of the EEG showed significant differences only in the spectral power of the beta rhythm in the central (p=0.048) and occipital (p=0.021) leads with closed eyes, which was lower in the group with a history of suicide attempts. The degree of alpha rhythm depression in the occipital leads was also significantly lower in this group (p=0.016). The regression analysis showed that significant correlates of suicidal attempts in patients with paranoid schizophrenia are the PANSS depressive factor (t=2.784; p=0.016) and a deficiency in the activation response to EEG (t=-2.035; p=0.045). The results complement previous studies on the relationship between suicidal attempts, clinical symptoms and neurophysiological features of the functioning of the brain of patients with paranoid schizophrenia.