title: Quantitative electroencephalography as a biomarker for proneness toward developing psychosis.
abstract: The fully dimensional approach to the relationship between schizotypal personality traits and schizophrenia describes schizotypy as a continuum throughout the general population ranging from low schizotypy (LoS) and psychological health to high schizotypy (HiS) and psychosis-proneness. However, no biological markers have yet been discovered that reliably quantify an individual's degree of schizotypy and/or psychosis. This study aimed to evaluate quantitative electroencephalographic (qEEG) measures of power spectra as potential biomarkers of the proneness towards the development of psychosis in schizotypal individuals. The resting-state oscillatory brain dynamics under eyes-closed condition from 16 LoS and 16 HiS individuals were analysed for qEEG measures of background rhythm frequency, relative power in δ, θ, low-α, high-α, low-β, high-β and low-γ frequency bands, and the high-temporal cross-correlation of power spectra between low- and high-frequency bands observed by averaging signals from whole-head EEG electrodes. HiS individuals at rest locked the thalamocortical loop in the low-α band at a lower-frequency oscillation and displayed an abnormally high level of neural synchronisation. In addition, the high-α band was found to be positively correlated with both the high-β and low-γ bands unlike LoS individuals, indicating widespread thalamocortical resonance in HiS individuals. The increase of regional alpha oscillations in HiS individuals suggests abnormal high-level attention, whereas the pattern of correlation between frequency bands resembles the thalamocortical dysrhythmia phenomenon which underlies the symptomatology of a variety of neuropsychiatric disorders including schizophrenia. These qEEG biomarkers may aid clinicians in identifying HiS individuals with a high-risk of developing psychosis.
authors: School of Psychology, College of Medicine, Biological Sciences and Psychology, University of Leicester, United Kingdom. Electronic address: g.fuggetta@le.ac.uk.
authors: Giorgio
authors: G
authors: Fuggetta
authors: School of Psychology, College of Medicine, Biological Sciences and Psychology, University of Leicester, United Kingdom.
authors: Matthew A
authors: MA
authors: Bennett
authors: School of Psychology, College of Medicine, Biological Sciences and Psychology, University of Leicester, United Kingdom.
authors: Philip A
authors: PA
authors: Duke
authors: School of Psychology, College of Medicine, Biological Sciences and Psychology, University of Leicester, United Kingdom.
authors: Andrew M J
authors: AM
authors: Young
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D015415:Biomarkers; D001931:Brain Mapping; D058256:Brain Waves / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000503:physiopathology*; D057566:Self Report; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: Electroencephalography (EEG); Resting-state oscillations; Schizotypy; Spectral analysis; Thalamocortical dysrhythmia (TCD)