Season of birth and electroencephalogram power abnormalities in schizophrenia.

To determine the association between season of birth and electroencephalogram (EEG) power abnormalities in schizophrenia, this study examined the resting EEGs of 28 winter-born and 81 nonwinter-born schizophrenia patients. Eighteen winter-born and 58 nonwinter-born nonschizophrenic psychosis patients (e.g., bipolar disorder patients with psychotic features), and 97 normal subjects were also studied. Compared to normal subjects, nonwinter-born schizophrenia patients had augmented low-frequency power and diminished alpha band power, but winter-born schizophrenia patients failed to have any EEG power abnormalities. Nonwinter-born nonschizophrenic psychosis patients had the same low-frequency and alpha band power abnormalities as nonwinter-born schizophrenia patients. The winter-born non-schizophrenic psychosis group failed to show any EEG power abnormalities. The results of this study indicate that in psychosis the functional characteristics of the brain vary depending on the season in which a person is born. Low-frequency and alpha band EEG power abnormalities may help distinguish psychosis stemming from a seasonally varying pathogen from psychosis of other etiologies.