Cognitive functioning, cortisol release, and symptom severity in patients with schizophrenia

Background: There is substantial evidence of dysregulation of cortisol secretion, hippocampal abnormalities, and memory deficits in schizophrenia and other psychotic disorders. Research also suggests that cortisol secretion augments dopaminergic activity, which may result in increased symptom expression in this clinical population. Methods: We examined the relations among cortisol release, cognitive performance, and psychotic symptomatology. Subjects were 18 adults with schizophrenia or schizoaffective disorder, seven with a nonpsychotic psychiatric disorder, and 15 normal control subjects. Tests of memory and executive function were administered. Cortisol was assayed from multiple saliva samples. Results: Findings indicated the following: 1) patients with psychotic disorders scored below the comparison groups on the cognitive measures; 2) for the entire sample, cortisol levels were inversely correlated with performance on memory and frontal tasks; and 3) among patients, cortisol levels were positively correlated with ratings of positive, disorganized, and overall symptom severity, but not with negative symptoms. Conclusions: The present results suggest that abnormalities in the hypothalamic–pituitary–adrenal axis and hippocampal systems play a role in observed cognitive deficits across populations. Among psychotic patients, elevated cortisol secretion is linked with greater symptom severity.