Negative symptoms in neuroleptic-naïve patients with first-episode psychosis correlate with QEEG parameters

Abstract

Introduction: While several studies have shown an association of QEEG band power with negative symptoms in patients with schizophrenia, this has not yet been investigated in a sample with neuroleptic-naïve first-episode patients (NNFE) up to now. From literature we hypothesized delta (0.5-4 Hz) and theta (4-8 Hz) power to be augmented and alpha (8)(9)(10)(11)(12) Hz) power to be decreased with increased negative symptoms in NNFE. Materials and methods:The sample consisted of 27 NNFE. Psychopathology was rated with the Scale for the Assessment of Negative Symptoms (SANS). EEG was recorded from 21 electrodes according to the 10/20 system. Spectral analysis was performed on mean power of 8 electrodes in seven frequency bands after artefact removal. Linear regressions were calculated with log transformed power as dependent and psychopathology as independent variable. We controlled for medication, drugs, age, sex, education and day time of EEG recording.Results: A positive correlation of SANS global scorewith power in delta and theta frequency bands could be confirmed in NNFE. In the alpha1 (8-10 Hz) band we found no significant correlation with negative symptoms and in the alpha2 (10-12 Hz) band therewas a positive correlation with SANS (p=0.069). Beta1 (12-15 Hz) power also correlated positively with SANS. Discussion:The present results confirm the correlation of negative symptoms with power of slow frequency bands. In addition to previous studies in chronic schizophrenia patients, the effect was shown in NNFE, which is compatible with augmented slow wave power being a marker for negative symptoms in psychosis.3

EEG spectral power and negative symptoms in at-risk individuals predict transition to psychosis

“…37 The positive correlations of EEG power and negative symptoms have been observed in chronic stages of schizophrenia, 20,23,25,27 in FE patients 28 and with the present study also in the prodromal phase of psychosis (ARMS-T) while the same correlations showed sign reversal in a non-psychotic control group (ARMS-NT). QEEG data might, thus, represent an endophenotype 38 associated with behavioral symptoms and could, therefore, be helpful in the differential diagnosis of disorders with negative symptoms.…”

“…28 The figure shows that FE and ARMS-T patients exhibit a remarkably similar correlation pattern across the entire EEG frequency range. In contrast, the correlation coefficients of ARMS-NT patients are dissimilar and largely in the negative range.…”

“…The first objective was to investigate whether the positive correlations of EEG power in the delta, theta, and beta1 bands with negative symptoms, previously observed in FE patients, 28 are already present before the clinical outbreak (in ARMS-T patients). Direction and degree of these correlations in ARMS-T patients are almost equivalent to those observed in FE patients (see Table 3), although confidence intervals were not clearly in the positive range, probably due to small sample size (N = 13).…”

“…This hypothesis originates from the observation that negative symptoms and quantitative EEG (qEEG) spectral power are correlated in different types of medicated and unmedicated schizophrenic patients. [19][20][21][22][23][24][25][26][27] Moreover, a recent study by our group 28 showed that negative symptoms are positively correlated with qEEG absolute power in delta (0.5-4 Hz), theta (4-8 Hz) and beta1 (12)(13)(14)(15) bands in the first episode (FE) of schizophrenia in neuroleptic-naïve patients. Presence of these correlations in neuroleptic naïve FE patients is a first requirement for the combination of negative symptoms with qEEG findings in ARMS patients to be a valid predictor for transition to psychosis.…”

Deep Brain Stimulation in Schizophrenia

“…It has been demonstrated in a quantitative EEG analysis, for instance, that increased amplitudes in the theta range (4 -8 Hz) correlate with the improvement of symptoms under clozapine, but the correlations became unstable with longer duration of treatment . However, correlations of theta power with negative symptoms (Scale for the Assessment of Negative Symptoms, (Andreasen, 1984) have been found in antipsychotic-naïve individuals as well (Gschwandtner et al, 2009). Nevertheless, identifying a particular brain structure as a target region of DBS based on the aforementioned correlations would overstrain these findings.…”