Schizotypal Personality in Healthy Adults Is Related to Blunted Cortisol Responses to the Combined Dexamethasone/ Corticotropin-Releasing Hormone Test

Abstract

Background/Aims: Schizotypy is viewed as a dimensional trait ranging from healthy people to schizophrenic spectrum patients. Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, and accumulated evidence suggests that schizophrenia is associated with altered HPA axis function; however, HPA axis function in relation to schizotypal personality has not been well documented. Methods: We examined the relationship between schizotypal traits as assessed with the Schizotypal Personality Questionnaire (SPQ) and cortisol responses to the combined dexamethasone/corticotropin- releasing hormone test in 141 healthy volunteers. Subjects were divided into three groups based on their cortisol responses to the dexamethasone/corticotropin-releasing hormone test: incomplete suppressors, moderate suppressors, and enhanced suppressors. SPQ scores were compared between these three groups using the analysis of covariance, controlling for age and sex. Results: The analysis of covariance showed significant main effects of the suppressor status on the ideas of reference and suspiciousness/paranoid ideation subscales and cognitive-perceptual factor. Post-hoc analyses with Bonferroni correction revealed that the enhanced suppressors scored significantly higher than the moderate suppressors on these SPQ indices. Conclusion: These results indicate that nonclinical schizotypal traits in healthy adults are associated with blunted cortisol reactivity, potentially suggesting a shared neuroendocrinological mechanism across schizophrenia spectrum pathology.

Possible association between Interleukin-1beta gene and schizophrenia in a Japanese population

“…Alleles associated with increased cortisol response to dexamethasone were shown to be associated with schizophrenia in the present study. Higher rates of non-suppression to dexamethasone compared to healthy subjects have been reported in schizophrenia [54] and schizotypy [55]. On the other hand, Ismail et al [56] reported that less than 2% of their schizophrenic patients were non-suppressors.…”

Modulation of cortisol responses to the DEX/CRH test by polymorphisms of the interleukin-1beta gene in healthy adults

“…Most of the subjects were from our previous sample, in which the relationship between stress, sleep, and HPA function was examined [36-38]. All subjects were biologically unrelated Japanese individuals without current or past history of psychiatric treatment, and were screened with a direct contact interview by a research psychiatrist using the Japanese version of the Mini International Neuropsychiatric Interview (M.I.N.I.)…”

Elevated Cortisol Level and Cortisol/DHEAS Ratio in Schizophrenia as Revealed by Low-Dose Dexamethasone Suppression Test

“…Cortisol values under the detection limit were treated as 0 nmol/l. As our hypothesis was that the two extreme ends of cortisol values (i.e., both exaggerated and blunted cortisol reactivity) would be related to schizophrenia, in the main analysis we also adopted the categorical division of participants based on a priori defined cut-off values of cortisol, i.e., 27.59 nmol/l (= 1.0 μg/dl) and 137.95 nmol/l (= 5.0 μg/dl), which were derived from several previous studies [12,[34][35][36]. 'Non-suppressors' were defined to be individuals whose cortisol level was equal to or more than 137.95 nmol/l.…”

“…On the other hand, studies employing psychosocial challenge paradigms have reported blunted cortisol responses in schizophrenia patients [5,6]. Individuals who are at risk for developing psychosis [7,8], those with first episode psychosis [9,10], and those *Address correspondence to this author at the Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawahigashi, Kodaira, Tokyo, 187-8502, Japan; Tel: +81 42 341 2711; Fax +81 42 346 1744; E-mail: hori@ncnp.go.jp with schizotypal personality [11,12] have also been shown to be associated with altered HPA axis function, although findings are again not uniform, that is, both hyper-and hypocortisolism are reported. All these findings indicate that although schizophrenia would be associated with altered HPA axis function, its precise nature is yet to be established.…”