Are Gender Differences in Schizophrenia Reflected in Brain Event-related Potentials?

Abstract

Numerous studies have reported relationships between gender and cerebral event-related potentials (ERPs) recorded from the human scalp. Recent studies have suggested that the influences of gender on ERPs may differ in persons with schizophrenia compared to healthy controls. In a further evaluation of the influences of this critical subject variable on ERP characteristics in schizophrenia, ERPs of age- and gender-matched groups (n = 72 each) of unmedicated schizophrenic patients and healthy controls were compared. ERPs elicited by left and right median nerve stimulation, checkerboard pattern visual flash, and auditory clicks were recorded from 15 scalp leads. The results confirm previous findings showing that: (1) number of comparable gender effects present in the ERP records of these two large study groups and (2) specific Diagnosis x Gender interactions suggesting that schizophrenic illness may modify normal gender influences on ERP characteristics. These data illustrate the point that matching schizophrenic patients and healthy control populations for gender is essential but not sufficient. Even in carefully matched groups, gender confounding can persist as a source of error variance because the influence can vary for different diagnostic groups.

Age at onset of schizophrenia: Gender differences and influence of temporal socioeconomic change

“…Some have reported that schizophrenic males have different morphological and physiological brain abnormalities, in addition to a lower family risk, than schizophrenic females. 9–20 Seeman and Lang hypothesized that estrogens account for many of the observed gender differences. 21 They noted that estrogens increase the density of dopamine type 2 receptors as do neuroleptics, and high levels of estrogens may serve a protective function in the onset of schizophrenia.…”

Gender differences in gating of the auditory evoked potential in normal subjects

“…The present data indicate that the influence of gender, in addition to chronological age (Freedman et al 1987a;Papanicolaou et al 1984), must be considered in studies of auditory gating. However, the relevance of the observed gender differences to psychopathology is unclear because of reports that psychiatric illness appears to modify normal gender influences on cortical evoked potentials (Josiassen et al 1990;Shagass et al 1972).…”

Reductions in the N1 and P2 Auditory Event-Related Potentials in First-Hospitalized and Chronic Schizophrenia

“…Roemer and Shagass 21 claimed medication reduced visual but not overall auditory N1 amplitudes. Josiassen et al 22 tested 72 unmedicated schizophrenia subjects and 72 controls and reported smaller N1 to clicks in schizophrenia. Kessler and Steinberg 9 reported reduced N1 in unmedicated paranoid schizophrenia but not in unmedicated residual/undifferentiated schizophrenia.…”