Similar extent of brain dysmorphology in severely ill women and men with schizophrenia.

OBJECTIVE: The purpose of this study was to determine whether women with chronic, severe schizophrenia manifest a widespread deficit in cortical gray matter and ventricular enlargement similar to that seen in men with schizophrenia and whether this deficit is related to age at onset of illness, length of illness, or current illness severity. METHOD: Volumetric measures of head size, cortical gray matter, white matter and sulci, and lateral and third ventricles were obtained from magnetic resonance images of chronic inpatient schizophrenic women (N = 19) and men (N = 18) and healthy comparison women (N = 19) and men (N = 18). Sex and group differences were assessed by using a two-factor analysis of variance of brain measures. Age was entered as a covariate in assessments of associations between brain measures and age at onset and length of illness. RESULTS: The schizophrenic patients as a group had less cortical gray matter but comparable white matter and significantly more lateral and third ventricular CSF than the comparison group. Compared to the combined groups of men, women, regardless of diagnosis, had smaller heads, less cortical gray and white matter, and less sulcal, lateral, and third ventricular CSF. There were no group-by-sex interactions, suggesting that in schizophrenia these aspects of gross volumetric morphology in male and female brains are affected equally. There was no relationship between cortical gray matter deficit or ventricular enlargements and age at symptom onset or length of illness in either men or women with schizophrenia, when variance due to age was accounted for statistically. CONCLUSIONS: The process that contributes to cortical gray matter deficit in schizophrenia appears to affect men and women to a similar extent.

Sex differences in neuropsychological functioning of first-episode and chronically ill schizophrenic patients.

OBJECTIVE: The purpose of this study was to determine whether men and women with schizophrenia demonstrate differences in cognitive abilities. METHOD: Two cohorts of patients with schizophrenia, an acute first-episode and a chronically hospitalized group, were evaluated with a neuropsychological battery and compared with a normal group of subjects. RESULTS: After adjustment for age, age at onset, and premorbid IQ, male chronic patients performed worse than female chronic patients on measures of visual memory. These differences were eliminated after control for symptom severity. No other differences were found in cognitive function between men and women in either cohort. CONCLUSIONS: Sex differences in cognitive function in schizophrenic patients are not robust findings.

Association of estrogen levels with neuropsychological performance in women with schizophrenia.

OBJECTIVE: This study sought to determine the relationship of estrogen levels with psychiatric symptoms and neuropsychological function in female patients with schizophrenia. METHOD: Psychiatric symptoms were assessed and average estrogen and progesterone levels from four consecutive weekly blood samples were measured in 22 female inpatients with schizophrenia who were also administered a neuropsychological battery. RESULTS: There were strong positive correlations between average estrogen level and cognitive function, especially measures of global cognitive function, verbal and spatial declarative memory, and perceptual-motor speed. Correlations of hormone levels with psychiatric symptoms were nonsignificant. CONCLUSIONS: Higher estrogen levels in female patients with schizophrenia are associated with better cognitive ability. These results may have implications for potential treatment of cognitive dysfunction with adjunctive estrogen in female patients with schizophrenia.

Functional connectivity and working memory in schizophrenia: an EEG study.

A leading hypothesis suggests that schizophrenic patients suffer from a disconnection syndrome. A failure in functional connectivity curtails the cortical integration and network activation needed to perform working memory tasks. Simulations with neural network models also indicate that connectivity is crucial for simulation of working memory asks. Multichannel EEG correlation-coefficient estimations are considered as a reliable measurement of connectivity patterns among cortical regions. In this study EEG samples are obtained selectively at the delay epochs of a delayed response working memory task. Results of correlation-coefficient estimations indicate a lack of statistically significant changes between non-task and task conditions in frontal, certain parietal, temporal and central channels. These findings propose that schizophrenics probably "fail" to activate the neural networks of the fronto-temporal regions. These are the networks involved in computation of the working memory task. Interestingly also good performers schizophrenics failed to activate these networks suggesting that the connectivity function is more relevant to the disorder than to task performance. If distinct deficits in cortical network activations would correlate with mental disorders it would be relevant to diagnosis and treatment of psychiatric disorders.