Reduced event-related low frequency EEG activity in patients with early onset schizophrenia and their unaffected siblings.
Low-frequency oscillations in the electroencephalogram (EEG) have been found to be abnormal in patients with schizophrenia. It is unclear, however, whether these abnormalities are related to severity of illness or are a marker for risk. This study investigated total and evoked theta and delta activity in schizophrenia patients, unaffected siblings, and healthy controls (HCs). EEG data were recorded whilst 24 individuals with schizophrenia, 26 unaffected siblings of individuals with schizophrenia and 26 healthy control participants completed a Go/No-Go task. Event-related total activity and evoked theta and delta activity were calculated for correct hits (CH), failed inhibitions (FI) and correct inhibitions (CI) trials. Patients displayed significantly less total delta, evoked delta, total theta and evoked theta activity when compared with healthy controls. Unaffected siblings displayed abnormalities of evoked delta, but other measures were similar to those in control participants. The findings of this study add to evidence that abnormal low-frequency EEG oscillations contribute to impairments in information processing seen in schizophrenia. These findings also suggest abnormal evoked delta oscillations are associated with an increased familial risk of developing the disorder.
Division of Psychiatry, University of Nottingham, Nottingham, UK. Electronic address: mollysimmonite@gmail.com.
Molly
M
Simmonite
Psychiatry Department, University of British Columbia, Vancouver, BC, Canada.
Alan Thomas
AT
Bates
Division of Psychiatry, University of Nottingham, Nottingham, UK.
Madeleine
M
Groom
Division of Psychiatry, University of Nottingham, Nottingham, UK.
Chris
C
Hollis
Division of Psychiatry, University of Nottingham, Nottingham, UK.
Peter Francis
PF
Liddle
D000293:Adolescent; D003700:Delta Rhythm / Q000502:physiology; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000503:physiopathology*; D035781:Siblings; D013826:Theta Rhythm / Q000502:physiology; D055815:Young Adult
Delta rhythm; Neural oscillations; Psychotic disorders; Theta rhythm