Diminished plasma oxytocin in schizophrenic patients with neuroendocrine dysfunction and emotional deficits

Goldman, Morris; Marlow-O'Connor, Megan; Torres, Ivan; Carter, C.S.

doi:10.1016/j.schres.2007.09.019

« Previous Next »Schizophrenia Research
Volume 98, Issue 1 , Pages 247-255, January 2008

Diminished plasma oxytocin in schizophrenic patients with neuroendocrine dysfunction and emotional deficits

Morris Goldman
- Department of Psychiatry, University of Chicago, 5841 South Maryland, Chicago, IL 60637 USA
- Psychiatric Institute, University of Illinois at Chicago in affiliation with University of Chicago, 1601 West Taylor, Chicago, IL 60612 USA
- Corresponding author. University of Chicago, Department of Psychiatry, 5841 South Maryland, MC3077, Chicago, IL 60637 USA. Tel.: +1 773 702 1542; fax: +1 708 383 6387.
Megan Marlow-O'Connor
- Psychiatric Institute, University of Illinois at Chicago in affiliation with University of Chicago, 1601 West Taylor, Chicago, IL 60612 USA
Ivan Torres
- Department of Psychology, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada, VSA 156
- British Columbia Mental Health and Addiction Services, 2601 Lougheed Highway, Coquitlam, British Columbia, Canada, V3C 4J2
C.S. Carter
- Psychiatric Institute, University of Illinois at Chicago in affiliation with University of Chicago, 1601 West Taylor, Chicago, IL 60612 USA

Received 16 June 2007; received in revised form 12 September 2007; accepted 16 September 2007. published online 25 October 2007.

Abstract

Polydipsic hyponatremic schizophrenic patients (PHS) exhibit enhanced plasma arginine vasopressin (pAVP) and hypothalamic pituitary adrenal (HPA) axis responses to stress that appear attributable to anterior hippocampal dysfunction. Neuroanatomic and electrophysiologic studies indicate oxytocin activity in PHS patients should also be affected. Furthermore, oxytocin normally diminishes HPA responses to stress and facilitates cognitive and behavioral functions impaired in schizophrenia, suggesting that diminished oxytocin activity could contribute to this subsets' neuropsychiatric disorder. In the present study, we measured plasma oxytocin levels at intervals before and after stress induction in six polydipsic hyponatremic (PHS), four polydipsic normonatremic (PNS), five nonpolydipsic normonatremic schizophrenic (NNS) patients and seven healthy controls. Most of these subjects also completed studies measuring their medial temporal lobe volumes, their hippocampal-mediated HPA feedback and their ability to discriminate different facial emotions (an oxytocin-sensitive measure which is markedly impaired in schizophrenia). Results demonstrated that 1) plasma oxytocin levels were lower (p=.006) in hyponatremic patients relative to the other three groups, whose levels were similar and did not change. Oxytocin levels across all subjects were 2) inversely correlated with anterior hippocampal (p=.004) (but not posterior hippocampal or amygdala volumes), and 3) directly correlated with the integrity of hippocampal-mediated HPA feedback (p=.039). Finally, 4) oxytocin levels predicted schizophrenic patients' ability to correctly identify facial emotions (p=.004). These preliminary data provide further evidence that neuroendocrine dysfunction in PHS reflects anterior hippocampal pathology and contributes to a characteristic neuropsychiatric syndrome.