The effects of metabolic stress on plasma progesterone in healthy volunteers and schizophrenic patients

Low Corticosterone Response to Stress in a Perimenopausal Rat Model Is Associated with the Hypoactivation of PaMP Region of the Paraventricular Nucleus and Can Be Corrected by Exogenous Progesterone Supplementation

INTRODUCTION

The transition to menopause is characterized by mood, behavioral and metabolic changes. However, little is known about the changes in adrenal response to stress.

AIMS

The aim of the study was to evaluate, in an animal model of perimenopause induced by 4-vinylcyclohexene diepoxide (VCD), (1) the endocrine and neuronal stress system activity in response to acute restraint stress and (2) the effect of hormonal therapy in this response.

METHODS

Prepubertal female Wistar rats received daily injections (s.c) of oil or VCD (160 mg/kg) for 15 days. On 56th-66th days after treatment onset, the groups to be stressed received s.c implants containing placebo (PL), 17β-estradiol (E2), progesterone (P4), or E2P4. At 80 ± 5 days after VCD/oil injections, stress was applied for 30 min. Blood samples were collected immediately after and 60 min after the end of stress session from the tail tip followed by transcardial perfusion with PFA 4% for the assessment of c-Fos expression in the medial and posterior parvocellular (PaMP and PaPo) subdivisions of the paraventricular nucleus (PVN) and c-Fos/tyrosine hydroxylase in the locus coeruleus (LC) using immunohistochemistry. Control groups were not stressed nor received hormone therapy.

RESULTS

While basal corticosterone levels were similar between VCD-periestropausal and control rats, the secretion in response to stress in the VCD group was lower. This effect was prevented by P4 therapy. Inversely, basal levels of P4 were lower in VCD-periestropausal rats than in the controls, and no differences were found in response to stress between the groups. As expected, 30-min restraint stress increased c-Fos immunoreactivity in all brain areas studied in both control and VCD-periestropausal rats. However, the c-Fos increase in the PaMP region was attenuated. In all areas examined, there were no significant differences in the number of c-Fos-positive neurons across hormonal therapies.

DISCUSSION/CONCLUSION

This is the first study to demonstrate in a perimenopausal rat model that reproductive aging is accompanied by inadequate secretion of corticosterone in response to acute stress in association with the hypoactivation of the PaMP region of the PVN, while adrenal P4 response is preserved. Moreover, P4 therapy was shown to attenuate the effects of progressive ovarian failure on adrenal functioning during stress.

The Gut Microbiome in Psychosis From Mice to Men: A Systematic Review of Preclinical and Clinical Studies

The gut microbiome is rapidly becoming the focus of interest as a possible factor involved in the pathophysiology of neuropsychiatric disorders. Recent understanding of the pathophysiology of schizophrenia emphasizes the role of systemic components, including immune/inflammatory and metabolic processes, which are influenced by and interacting with the gut microbiome. Here we systematically review the current literature on the gut microbiome in schizophrenia-spectrum disorders and in their animal models. We found that the gut microbiome is altered in psychosis compared to healthy controls. Furthermore, we identified potential factors related to psychosis, which may contribute to the gut microbiome alterations. However, further research is needed to establish the disease-specificity and potential causal relationships between changes of the microbiome and disease pathophysiology. This can open up the possibility of. manipulating the gut microbiome for improved symptom control and for the development of novel therapeutic approaches in schizophrenia and related psychotic disorders.

HPA axis in psychotic major depression and schizophrenia spectrum disorders: Cortisol, clinical symptomatology, and cognition

The Hypothalamic Pituitary Adrenal (HPA) axis has been implicated in the pathophysiology of a variety of mood and cognitive disorders. Neuroendocrine studies have demonstrated HPA axis overactivity in major depression, a relationship of HPA axis activity to cognitive performance, and a potential role of HPA axis genetic variation in cognition. In schizophrenia differential HPA activity has been found, including higher rates of non-suppression to dexamethasone challenge and higher salivary cortisol levels, which have been a premonitory risk factor for conversion to psychosis in adolescents at risk for developing schizophrenia. The present study investigated the simultaneous roles HPA axis activity and clinical symptomatology play in poor cognitive performance. Patients with major depression with psychosis (PMD) or schizophrenia spectrum disorder (SCZ) and healthy controls (HC) were studied. All participants underwent a diagnostic interview and psychiatric ratings, a comprehensive neuropsychological battery, and overnight hourly blood sampling for cortisol. Cognitive performance did not differ between the clinical groups, though they both performed more poorly than the HC's across a variety of cognitive domains. Across all subjects, cognitive performance was negatively correlated with higher cortisol, and PMD patients had higher evening cortisol levels than did SCZ and HCs. Cortisol and clinical symptoms, as well as age, sex, and antipsychotic use predicted cognitive performance. Diathesis stress models and their links to symptomatology, cognition, and HPA function are discussed.

Effects of hormonal contraceptive phase and progestin generation on stress-induced cortisol and progesterone release

The stress response differs between women using hormonal contraception and naturally cycling women. Yet, despite ample evidence showing that the stress response differs across the menstrual cycle in naturally cycling women, limited work has investigated whether the stress response differs across the hormonal contraceptive cycle, during which synthetic hormones are taken most of the month but not all of it. To induce a stress response, women using hormonal contraception completed the cold pressor test during either the active phase, when hormones are present, or during the inactive phase, when hormones are not present. Saliva was collected and assayed for free cortisol and progesterone levels prior to stress onset, immediately after stress termination, and 15-min post stress onset. Free cortisol and progesterone increased to a similar degree across both hormonal contraceptive phases in response to the cold pressor test. Post-hoc investigation indicates that the progestin “generation” (classification of synthetic progestins based on the compounds they are derived from) can differentially affect the free steroid response to cold pressor test stress, with the largest effects observed in women using formulations containing second-generation progestins. These findings indicate that progestin generation, particularly second-generation progestins, may have a more impactful influence on the stress response than hormonal contraceptive cycle phase. Potential mechanisms driving this effect and need for additional research are discussed.

Pregnenolone-progesterone-allopregnanolone pathway as a potential therapeutic target in first-episode antipsychotic-naïve patients with schizophrenia

Neurosteroids are both endogenous and exogenous steroids that rapidly alter neuronal excitability through interactions with ligand-gated ion channels and other cell surface receptors. They are originated from cholesterol and have important implications for schizophrenia (SZ) pathophysiology and treatment strategies. Specifically, pregnenolone (PREG), progesterone (PROG) and allopregnanolone (ALLO) exhibit similar psychotropic properties. Using enzyme immunoassay, we compared the neurosteroids in PREG downstream pathways in plasma between healthy controls (HC, n = 43) and first-episode antipsychotic-naïve patients with SZ (FEAN-SZ, n = 53) before antipsychotic drug (APD) treatment. Comparisons were also made particularly along PREG-PROG-ALLO pathway in the same FEAN-SZ patients across multiple time points following initiation of treatment for 12 months (m). Firstly, at baseline, levels of PREG were significantly higher and those of ALLO were lower in FEAN-SZ than in HC, whereas PROG, cortisol, dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) were not different. Consequently, the molar ratios of ALLO/PREG and ALLO/PROG in FEAN-SZ were significantly reduced. Secondly, in response to APD at 1 month, ALLO levels in FEAN-SZ were markedly elevated, whereas PREG and PROG levels decreased. Thirdly, among FEAN-SZ, lower levels of PROG (reflecting higher conversion to ALLO) at baseline may predict better therapeutic outcome after 1 month of APD treatment. These findings point to the perturbations of the PREG-PROG-ALLO pathway early in psychosis, and further study of this pathway may inform alternative and innovative therapeutic targets for SZ.

Neurosteroids in Schizophrenia: Pathogenic and Therapeutic Implications

Neurosteroids are a group of important endogenous molecules affecting many neural functions in the brain. Increasing evidence suggests a possible role of these neurosteroids in the pathology and symptomatology of schizophrenia (SZ) and other mental disorders. The aim of this review is to summarize the current knowledge about the neural functions of neurosteroids in the brain, and to evaluate the role of the key neurosteroids as candidate modulators in the etiology and therapeutics of SZ. The present paper provides a brief introduction of neurosteroid metabolism and distribution, followed by a discussion of the mechanisms underlying neurosteroid actions in the brain. The content regarding the modulation of the GABAA receptor is elaborated, given the considerable knowledge of its interactions with other neurotransmitter and neuroprotective systems, as well as its ameliorating effects on stress that may play a role in the SZ pathophysiology. In addition, several preclinical and clinical studies suggested a therapeutic benefit of neurosteroids in SZ patients, even though the presence of altered neurosteroid pathways in the circulating blood and/or brain remains debatable. Following treatment of antipsychotic drugs in SZ, therapeutic benefits have also been linked to the regulation of neurosteroid signaling. Specifically, the neurosteroids such as pregnenolone and dehydroepiandrosterone affect a broad spectrum of behavioral functions through their unique molecular characteristics and may represent innovative therapeutic targets for SZ. Future investigations in larger cohorts with long-term follow-ups will be required to ascertain the neuropsychopharmacological role of this yet unexploited class of neurosteroid agents.

Low glucose availability stimulates progesterone production by mouse ovaries in vitro

Steroid production by the ovary is primarily stimulated by gonadotropins but can also be affected by biological cues that provide information about energy status and environmental stress. To further understand which metabolic cues the ovary can respond to, we exposed gonadotropin-stimulated mouse ovaries in vitro to glucose metabolism inhibitors and measured steroid accumulation in media. Gonadotropin-stimulated ovaries exposed to 2-deoxy-d-glucose increased progesterone production and steroidogenic acute regulatory protein mRNA levels. However, oocytes and granulosa cells in antral follicles do not independently mediate this response because targeted treatment of these cell types with a different inhibitor of glucose metabolism (bromopyruvic acid) did not affect progesterone production. Elevated progesterone production is consistent with the homeostatic role of progesterone in glucose regulation in mammals. It also may regulate follicle growth and/or atresia within the ovary. These results suggest that ovaries can regulate glucose homeostasis in addition to their primary role in reproductive activity.

Altered circadian patterns of salivary cortisol in individuals with schizophrenia: A critical literature review

This article focuses on stress vulnerability in schizophrenia through an integrated clinical and biological approach. The objective of this article is to better understand the relationships between vulnerability, stress and schizophrenia. First, the concept of vulnerability is defined and several models of vulnerability in schizophrenia are reviewed. Second, a section is developed on the biology of stress, and more specifically on the stress responses of the hypothalamo-pitutary adrenal (HPA) axis. Then, studies of cortisol circadian rhythms are summarized, suggesting hyper-reactivity of the HPA axis in patients with schizophrenia and high risk individuals for schizophrenia. The results support the models of stress vulnerability in schizophrenia and the hypothesis of high cortisol levels as an endophenotype in this disorder. In conclusion, this article highlights the interest of studying the cortisol circadian rhythms in schizophrenia and opens the perspective to identify high risk individuals for schizophrenia by measuring circadian patterns of salivary cortisol.

Sex Steroids and Major Psychoses: Which Role for DHEA-S and Progesterone

OBJECTIVE

Endocrine pathways seem to play a role in the etiology of major psychoses. The identification of biomarkers associated with psychotic symptoms in schizophrenia (SKZ) and mood disorders would allow the identification of high-risk subjects for delusions and hallucinations. The aim of this study was to evaluate dehydroepiandrosterone sulfate (DHEA-S) and progesterone plasma levels in drug-free patients with major psychoses and their relation with the diagnosis and history of psychotic symptoms.

METHODS

Eighty-nine consecutive drug-free male inpatients with SKZ or mood disorders were recruited, and DHEA-S and progesterone plasma levels were measured. The groups, divided according to pathological/normal-range hormone levels, were compared in terms of clinical variables using x03C7;2 tests with Bonferroni's corrections or multivariate analyses of variance. The same analyses were performed for groups divided according to the presence/absence of lifetime psychotic symptoms. Binary logistic regression analysis was performed using hormone levels as independent variables and history of lifetime psychotic symptoms as a dependent one.

RESULTS

A higher number of patients with abnormal DHEA-S levels was found to have a family history of major depressive disorder (p < 0.05). Higher DHEA-S levels (F = 8.31; p = 0.005) were found in patients with a history of psychotic symptoms. In addition, binary logistic regression confirmed that DHEA-S levels were associated with a higher probability of lifetime psychotic symptoms (p = 0.037).

CONCLUSIONS

Our results confirm previous data about the role of endocrine factors in the etiology of major psychoses. A high DHEA-S level might be a risk factor for psychotic symptoms. Studies with larger samples are needed to confirm these data.

Stress-induced increases in progesterone and cortisol in naturally cycling women

Studies with animals of both sexes show that the adrenal glands release progesterone in addition to cortisol in response to stress. However, little is known about the progesterone response to stress in naturally cycling women. We investigated the effect of stress on estradiol, progesterone, and cortisol levels in women during the follicular phase of the menstrual cycle. We found that physical stress (the cold pressor test) had no effect on estradiol levels, but increased progesterone and cortisol. We also found positive correlations between baseline progesterone and cortisol levels, as well as between the change in progesterone and cortisol before and after water exposure in both the stress and control sessions. Mediation analyses revealed during the stress session, the change in progesterone from baseline to 42-min post-stress onset was mediated by the magnitude of change in cortisol levels across the same time span. Overall, these findings reveal that progesterone released in response to stress as observed in animals and men extends to women during the low ovarian output follicular phase of the menstrual cycle, and that the mechanism of release may be similar to the mechanism of cortisol release.

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Progesterone rises in response to stress during the follicular phase.

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Baseline progesterone was associated with greater cortisol response to stress.

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Cortisol response to stress mediated progesterone responses to stress.

Contribution of sex hormones to gender differences in schizophrenia: A review

Female patients with schizophrenia tend to have a more benign course and better outcomes than males. One proposed explanation is the differential influence of male and female sex hormones, including estrogen, progesterone, testosterone, and dehydroepiandrosterone (DHEA) and its sulfate (DHEAS). Such benefit may be mediated by their effects on neurotransmitters and neuroprotection. Besides altered estrogen and DHEA/DHEAS levels in female patients, data is equivocal on hormonal differences between patients and controls. However, several reports note a mostly negative correlation between estrogen levels and symptom severity in both genders, and a positive correlation between estrogen levels and neurocognition but mainly in females. Adjunctive estrogen appears to improve symptoms in both genders. Progesterone levels have inconsistent links to symptom severity in both genders, and correlate positively with neurocognition but only in males. Estrogen-progesterone combination shows preliminary benefits as augmentation for both symptoms and neurocognition in females. Testosterone levels correlate inversely with negative symptoms in males and have inconsistent associations with neurocognition in both genders. Testosterone augmentation reduced negative symptoms in male patients in a pilot investigation, but has not been evaluated for neurocognition in either gender. DHEA/DHEAS have mixed results for their association with, and clinical utility for, symptoms and neurocognition in both genders. Overall, data on the impact of sex hormones on clinical course or as treatment for schizophrenia is limited, but estrogen has most evidence for positive influence and clinical benefit. The possibly greater tolerability and broader impact of these hormones versus existing medications support further exploration of their use.

Morning cortisol levels in schizophrenia and bipolar disorder: a meta-analysis

Increased peripheral levels of morning cortisol have been reported in people with schizophrenia (SZ) and bipolar disorder (BD), but findings are inconsistent and few studies have conducted direct comparisons of these disorders. We undertook a meta-analysis of studies examining single measures of morning cortisol (before 10 a.m.) levels in SZ or BD, compared to controls, and to each other; we also sought to examine likely moderators of any observed effects by clinical and demographic variables. Included studies were obtained via systematic searches conducted using Medline, BIOSIS Previews and Embase databases, as well as hand searching. The decision to include or exclude studies, data extraction and quality assessment was completed in duplicate by LG, SM and AS. The initial search revealed 1459 records. Subsequently, 914 were excluded on reading the abstract because they did not meet one or more of the inclusion criteria; of the remaining 545 studies screened in full, included studies were 44 comparing SZ with controls, 19 comparing BD with controls, and 7 studies directly comparing schizophrenia with bipolar disorder. Meta-analysis of SZ (N=2613, g=0.387, p=0.001) and BD (N=704, g=0.269, p=0.004) revealed moderate quality evidence of increased morning cortisol levels in each group compared to controls, but no difference between the two disorders (N=392, g=0.038, p=0.738). Subgroup analyses revealed greater effect sizes for schizophrenia samples with an established diagnosis (as opposed to 'first-episode'), those that were free of medication, and those sampled in an inpatient setting (perhaps reflecting an acute illness phase). In BD, greater morning cortisol levels were found in outpatient and non-manic participants (as opposed to those in a manic state), relative to controls. Neither age nor sex affected cortisol levels in any group. However, earlier greater increases in SZ morning cortisol were evident in samples taken before 8 a.m. (relative to those taken after 8 a.m.). Multiple meta-regression showed that medication status was significantly associated with morning cortisol levels in SZ, when the effects of assay method, sampling time and illness stage were held constant. Heightened levels of morning cortisol in SZ and BD suggest long-term pathology of the hypothalamic-pituitary-adrenal (HPA) axis that may reflect a shared process of illness development in line with current stress-vulnerability models.

The role of cortisol in first episode of psychosis: a systematic review

The stress diathesis hypothesis is currently one of the prevailing models of etiology of psychotic disorders. Cortisol is the most researched stress hormone; yet its role in first episode psychosis (FEP) was only recently investigated. The aim of the present study is to systematically review the evidence on the potential role of cortisol in FEP. Higher cortisol levels in blood samples have been consistently replicated, whereas saliva studies measuring baseline cortisol levels have exhibited divergent results. Moreover, longitudinal studies have revealed a cortisol upregulation in FEP with a subsequent decrease induced by antipsychotic treatment. The evidence suggests a role for cortisol in psychosis, although the association of cortisol with psychopathological symptoms is currently non-specific. Future research should focus on more pure diagnostic entities, clearly defined stages of the disorder and refined methods of hormonal measurement.

Polymorphisms in AKR1C4 and HSD3B2 and differences in serum DHEAS and progesterone are associated with paranoid ideation during mania or hypomania in bipolar disorder

Paranoia is commonly a mood-incongruent psychotic symptom of mania which may be related to dopamine dysregulation. Progesterone and its metabolite allopregnanolone (ALLO) have been found in animals to antagonize the effects of dopamine. We therefore examined serum progesterone, its endogenous antagonist DHEAS and polymorphisms of the genes coding for certain steroidogenetic enzymes (AKR1C4, HSD3B2, and SRD5A1) in 64 males and 96 females with bipolar 1 or 2 disorder with or without paranoid ideation during mood elevation. Euthymic morning serum progesterone, DHEAS and cortisol concentrations were measured in males and in premenopausal women who were in follicular phase and not taking oral contraceptives. In women only, SNPs in AKR1C4 reduced the likelihood of having exhibited paranoid ideation by circa 60%. The haplotype of all 4 SNPs in the AKR1C4 gene reduced the risk of exhibiting paranoia by 80% (OR 0.19, 95% CI 0.06-0.61, p=0.05). A history of paranoid ideation was not, however, related to progesterone or DHEAS concentration. Serum DHEAS and progesterone concentrations were lower in men who had shown paranoid ideation during mania/hypomania compared with those who had not (F=7.30, p=0.006) however this was not coupled to polymorphisms in the selected genes. The ancestral G in rs4659174 in HSD3B2 was in men associated with a lower risk of paranoid ideation (likelihood ratio χ(2) 3.97, p=0.046, OR 0.31 (95% CI 0.10-0.96)) but did not correlate with hormone concentrations. Hence, gene variants in the steroidogenetic pathway and steroids concentration differences may be involved in the susceptibility to paranoia during mood elevation.

Impaired neuroendocrine and immune response to acute stress in medication-naive patients with a first episode of psychosis

Little is known about how the biological stress response systems--the autonomic nervous system (ANS), the hypothalamic-pituitary-adrenal (HPA) axis, and the immune system--function during psychosis. Results of studies on the effect of stress on the immune and autonomic system in patients with schizophrenia are inconsistent. The present study investigates whether the stress response is impaired in medication-naive patients with a first episode of psychosis. Ten male patients with a first episode of psychosis and 15 controls were exposed to the stress of public speaking. Parameters of the ANS (heart rate and catecholamines), the HPA axis (plasma adrenocorticotropic hormone [ACTH] and cortisol), and the immune system (number and activity of natural killer [NK] cells) were measured. Peak responses were calculated to examine the relationship between stress-induced activation of the different systems. Subjective stress and anxiety before and during the task were assessed. Patients and controls displayed similar autonomic responses to acute stress. However, there was an impaired HPA axis response, slow onset and return of ACTH, and flattened cortisol response and a reduced increase in number NK cells and NK cell activity in patients with a first episode of psychosis. Furthermore, in patients, the relationship between the different stress response systems was weaker or absent compared with controls. These findings indicate that impairments in stress processing are associated with the endophenotype of psychosis and are not a result of illness progression or antipsychotic medication.

Schizotypal personality in healthy adults is related to blunted cortisol responses to the combined dexamethasone/ corticotropin-releasing hormone test

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.

Sex differences and hormonal influences in human sensorimotor gating: implications for schizophrenia

Prepulse inhibition (PPI) of the startle response serves to prevent the interruption of ongoing perceptual and early sensory analysis and provides a simple operational measure of sensorimotor gating. In line with postulated deficits in early stages of information processing, PPI is disrupted in schizophrenia. PPI is considered a valid candidate for an endophenotypic marker in genetic studies of schizophrenia and has also been extensively used in translational research. Importantly, there are well-replicated sex differences and menstrual phase effects in prepulse-elicited startle modulation of nonclinical young populations. Lack of knowledge about the precise roles of sex differences and hormonal effects in prepulse-elicited startle modulation and in the schizophrenia disease process presents a stumbling block to continuous progress in this field. This chapter reviews a wealth of data demonstrating sex and hormonal influences in prepulse-elicited startle modulation and considers their implications for our understanding of the pathophysiology, genetics, and potential treatments of schizophrenia.

A randomised controlled study of risperidone and olanzapine for schizophrenic patients with neuroleptic-induced acute dystonia or parkinsonism

The objective of this study was to compare the effects of risperidone and olanzapine in schizophrenic patients with intolerant extrapyramidal side effects (EPS) on first generation antipsychotics. We conducted an 8-week, rater-blinded, flexible dose study. Seventy patients with schizophrenia, who met the DSM-IV research criteria of having neuroleptic-induced acute dystonia or parkinsonism, were randomly assigned to risperidone or olanzapine group. The primary outcome was a comparison of the incidence of concomitant anticholinergic drugs usage between the groups to manage their acute dystonia and parkinsonism. The average doses of risperidone and olanzapine from baseline to study end point were 1.8-3.5 mg/day and 7.7-11.7 mg/day, respectively. There were no significant differences in demographic data, severity of EPS or psychotic symptoms between the groups at baseline assessment. Patients taking risperidone had significantly higher incidence of using anticholinergic drugs to manage acute dystonia or parkinsonism overall during the study (OR = 5.17, 95%CI = 1.49-17.88, P = 0.013). There was no significant between-group difference in the changing of rating scales of EPS and psychotic symptoms. The results of our study favour olanzapine as a better choice in schizophrenic patients with intolerant EPS. Double-blinded, fixed dose and different ethnical study for EPS-intolerant schizophrenic patients is needed to confirm the results of our study.

A systematic review of hypothalamic-pituitary-adrenal axis function in schizophrenia: implications for mortality

There is convincing evidence that environmental stress plays a significant role in modifying both mental and physical health. The biological mechanisms linking stress to ill health are not fully understood, but significant evidence points to a central role of the stress axes; the hypothalamic- pituitary-adrenal (HPA) axis and the sympathetic nervous system. Together these two systems link the brain and the body and are crucial in maintaining homeostasis as well as improving an organism's survival chances in the face of environmental challenge. There is evidence of altered HPA axis function in people with a range of mental disorders, and this may in part explain the poor physical health of people with psychotic, mood and anxiety disorders. This paper systematically reviews HPA axis function in people with schizophrenia and relates this to the pattern of physical health seen in this disease. In summary, the evidence suggests people with schizophrenia can experience both hyper- and hypo-function of the HPA axis. It is likely that this contributes to the pattern of poor physical health and premature mortality suffered by people with schizophrenia, in particular the high rates of cardiovascular and metabolic disturbance.

Evidence for a role of progesterone in menstrual cycle-related variability in prepulse inhibition in healthy young women

Prepulse inhibition (PPI) of the startle response is sensitive to sex, with healthy young women showing less PPI compared with age-matched men, and varies according to the menstrual cycle phase in women. Relatively less is known regarding sex and hormonal influences in prepulse facilitation (PPF). Menstrual phase-related variability in PPI is suggested to be mediated by fluctuating estrogen level, based on the observations of more PPI in women during the follicular, relative to the luteal, phase. No study has directly assessed the relationship between fluctuating hormones and PPI or PPF levels over the human ovarian cycle. To examine the roles of circulating ovarian hormones in PPI and PPF, 16 non-smoking regularly menstruating healthy women were tested during both the follicular and luteal phases on PPI and PPF and provided saliva samples for measurement of 17beta-estradiol (estrogen), progesterone and testosterone. The results showed higher levels of 17beta-estradiol and progesterone during the luteal, relative to the follicular, phase; and more PPI during the follicular phase and more PPF during the luteal phase with comparable startle amplitude and habituation during the two phases. A larger increase in progesterone was associated with a smaller decrease in PPI from the follicular to the luteal phase. No significant associations were found between changes in PPI/PPF and estrogen levels. The findings confirm lower PPI during the luteal, compared with the follicular, phase and suggest a role for progesterone, more specifically an antipsychotic-like PPI-restoration action of progesterone, during the luteal phase in PPI of young women.

The developmental pathways to schizophrenia: Potential moderating effects of stress

The observations of family members as well as the results of past research suggest that a variety of developmental pathways can precede the onset of schizophrenia in early adulthood. In this article, we describe recent findings from our research on the childhood precursors of schizophrenia. Taken together, the results indicate that childhood behavioral, emotional, and motoric dysfunction occur at a higher rate in preschizophrenia subjects when compared to control subjects. Further, there are developmental changes as well as significant variability among schizophrenia patients in the nature and severity of childhood impairment. Drawing on the prevailing diathesis-stress model, we explore the moderating role that stress exposure and reactivity may play in the expression of the organic diathesis for schizophrenia. Specifically, we consider the role of the biological stress response in the production of developmental changes and individual differences in the pathways to schizophrenia. Given extant models of dopamine involvement in the neuropathology of schizophrenia, stress-induced Cortisol release may alter the expression of subcortical abnormalities in dopamine neurotransmission. Thus, we present a neural mechanism for the hypothesized behavioral sensitivity to stress exposure in schizophrenia, and explore the capacity of the model to account for the changing behavioral manifestations of vulnerability.

The relevance of neuroactive steroids in schizophrenia, depression, and anxiety disorders

1. Neuroactive steroids are steroid hormones that exert rapid, nongenomic effects at ligand-gated ion channels. There is increasing awareness of the possible role of these steroids in the pathology and manifestation of symptoms of psychiatric disorders. The aim of this paper is to review the current knowledge of neuroactive steroid functioning in the central nervous system, and to assess the role of neuroactive steroids in the pathophysiology and treatment of symptoms of schizophrenia, depression, and anxiety disorders. Particular emphasis will be placed on GABAA receptor modulation, given the extensive knowledge of the interactions between this receptor complex, neuroactive steroids, and psychiatric illness. 2. A brief description of neuroactive steroid metabolism is followed by a discussion of the interactions of neuroactive steroids with acute and chronic stress and the HPA axis. Preclinical and clinical studies related to psychiatric disorders that have been conducted on neuroactive steroids are also described. 3. Plasma concentrations of some neuroactive steroids are altered in individuals suffering from schizophrenia, depression, or anxiety disorders compared to values in healthy controls. Some drugs used to treat these disorders have been reported to alter plasma and brain concentrations in clinical and preclinical studies, respectively. 4. Further research is warranted into the role of neuroactive steroids in the pathophysiology of psychiatric illnesses and the possible role of these steroids in the successful treatment of these disorders.

Altered levels of sex and stress steroid hormones assessed daily over a 28-day cycle in early abstinent cocaine-dependent females

RATIONALE

There is growing evidence of alterations in brain stress and reward circuits associated with cocaine dependence. Sex differences are also documented and sex steroid hormones have been linked to cocaine reinforcement.

OBJECTIVES

The current study therefore assessed daily fluctuations in stress and sex hormones in cocaine-dependent females compared with healthy females.

METHOD

Daily salivary samples of cortisol, progesterone, and estradiol were collected at waking across 28 days from 12 cocaine-dependent females receiving inpatient treatment and 10 healthy females. Participants also completed mood-rating scales each week corresponding to four phases of the menstrual cycle and cocaine craving was monitored in cocaine patients at each phase.

RESULTS

Cocaine-dependent females in their first month of abstinence demonstrated significantly higher levels of both cortisol and progesterone across the menstrual cycle and significantly lower estradiol/progesterone (E2/P) ratios compared to healthy controls. They also showed significantly increased negative mood compared with controls, but no variation in cocaine craving across the menstrual cycle.

CONCLUSIONS

Findings indicate altered stress and sex hormones suggestive of an overactive stress system during the first month of cocaine abstinence after chronic cocaine abuse. These increased levels of cortisol and progesterone could impact both abstinence-related symptoms such as negative mood and susceptibility to drug-seeking behavior in cocaine-dependent females.

Stress, the hippocampus and the hypothalamic-pituitary-adrenal axis: implications for the development of psychotic disorders

OBJECTIVE

The experience of stress is commonly implicated in models of the onset of psychotic disorders. However, prospective studies investigating associations between biological markers of stress and the emergence of psychotic disorders are limited and inconclusive. One biological system proposed as the link between the psychological experience of stress and the development of psychosis is the Hypothalamic-Pituitary-Adrenal (HPA) axis. This paper summarizes and discusses evidence supporting a role for HPA-axis dysfunction in the early phase of schizophrenia and related disorders.

METHOD

A selective review of psychiatric and psychological research on stress, coping, HPA-axis, the hippocampus and psychotic disorders was performed, with a particular focus on the relationship between HPA-axis dysfunction and the onset of psychotic disorders.

RESULTS

Individual strands of past research have suggested that the HPA-axis is dysfunctional in at least some individuals with established psychotic disorders; that the hippocampus is an area of the brain that appears to be implicated in the onset and maintenance of psychotic disorders; and that an increase in the experience of stress precedes the onset of a psychotic episode in some individuals. Models of the onset and maintenance of psychotic disorders that link these individual strands of research and strategies for examining these models are proposed in this paper.

CONCLUSIONS

The current literature provides some evidence that the onset of psychotic disorders may be associated with a higher rate of stress and changes to the hippocampus. It is suggested that future research should investigate whether a relationship exists between psychological stress, HPA-axis functioning and the hippocampus in the onset of these disorders. Longitudinal assessment of these factors in young people at 'ultra' high risk of psychosis and first-episode psychosis cohorts may enhance understanding of the possible interaction between them in the early phases of illness.

Neuroactive steroids in schizophrenia

Schizophrenia is a psychiatric disorder with a complicated pathophysiology, involving many biochemical abnormalities in the brain. Because neuroactive steroids (NASs) modulate neurotransmitter systems that are implicated in the pathology of schizophrenia, recent research has focused on examining the role that NASs play in the illness. Although research in this area is relatively new, it appears that NASs may potentially be implicated in the pathophysiology of the illness. This paper reviews the current understanding of NASs, the research literature on NASs in schizophrenia and in animal models of the illness (including the effects of antipsychotic medication on NASs) and on the potential antipsychotic role of NASs themselves and, finally, discusses future directions for this area of schizophrenia research.

Interactions of chronic lead exposure and intermittent stress: consequences for brain catecholamine systems and associated behaviors and HPA axis function

Elevated lead (Pb) burden and high stress levels are co-occurring risk factors in low socioeconomic status (SES) children. Our previous work demonstrated that maternal Pb exposure can permanently alter hypothalamic-pituitary-adrenal (HPA) axis function and responsivity to stress challenges in offspring. The current study sought to determine the consequences of chronic Pb exposures initiated later in development combined with variable intermittent stress challenges. Male rats were exposed chronically from weaning to 0, 50, or 150 ppm Pb acetate drinking solutions (producing blood Pb levels of <5, 9-15, and 23-27 mug/dl, respectively). Pb itself decreased basal plasma corticosterone, with greater effects at 50 than 150 ppm; 150 ppm reduced both cytosolic and nuclear glucocorticoid receptor binding. Responsivity to stress challenges including novelty, cold, and restraint, was measured as changes in Fixed Interval (FI) schedule-controlled behavior in a subset of rats within each group. FI performance was modified by novelty stress only in Pb-treated rats, whereas cold and restraint stress effects were comparable across groups. Novelty elevated corticosterone equivalently across groups, but cold stress markedly increased corticosterone only in Pb-treated groups. The pattern of Pb-induced changes in serotonin (5-HT) or its metabolite 5-HIAA in frontal cortex, nucleus accumbens, striatum, and hypothalamus resembled that observed for basal corticosterone levels indicating a relationship between these variables. In addition to suggesting the potential for HPA axis-mediated effects of Pb on the central nervous system, these findings also raise questions about whether single chemicals studied in isolation from other relevant risk factors can adequately identify neurotoxic hazards.

Male patients with paranoid schizophrenia have greater ACTH and cortisol secretion in response to metoclopramide-induced AVP release

Dynamic testing of the hypothalamic-pituitary-adrenal axis in schizophrenia has yielded conflicting results, which may be related to patient selection and previous exposure to psychotropic medication. The objective of this study was to determine the pattern of corticotropin (ACTH) and cortisol release in response to metoclopramide (a dopamine antagonist), which appears to be unique in its ability to release vasopressin (AVP), in drug naive patients with schizophrenia experiencing their first episode of psychosis. In this study, we examined AVP, ACTH and cortisol release in response to metoclopramide in 10 drug-naive, first-episode male patients with a DSM IV diagnosis of paranoid schizophrenia and compared them to healthy control subjects matched for age, sex and smoking status. Patients, as compared to controls had higher levels of baseline plasma cortisol (375.5+/-47.4/l vs. 273.8+/-42.2 nmol/l, respectively; t=2.48, df=9, p< 0.02) and plasma ACTH (14.9+/-0.85 vs. 11.3+/-0.57 pg/ml, respectively; t=4.29, df=9, p<0.001). AVP levels were lower in patients though this did not reach statistical significance (0.89+/-0.09 vs. 1.3+/-0.08 pmol/l, respectively; t=1.97, df=9, p<0.07). A repeated measures 2-way ANOVA to compare responses to metoclopramide over time between the two groups yielded a significant group by time interaction for cortisol (F=11.3, df=6, 108, p<0.001) and ACTH (F=15.65, df=6, 108, p<0.002). Post hoc Tukey's test revealed significant differences between the two groups at +30, +45, +60, +90 and +120 min for cortisol (p<0.01) and at +30, +45, +60 and +90 min for ACTH (p<0.01). The group by time interactions continued to remain significant when cortisol (F=10.9, df=6, 107, p<0.001) and ACTH (F=13.04, df=6, 108, p<0.002) were entered as co-variates. There was a significant positive correlation between AVP and cortisol responses in patients (r=0.65, df=8, p<0.01). Male patients with paranoid schizophrenia release greater amounts of ACTH and cortisol in responses to metoclopramide-induced AVP secretion than control subjects.

Schizophrénie, diabète et antipsychotiques

During the last years, a contribution of antipsychotic drugs in the increase of diabetes prevalence in schizophrenic population has been repetitively suggested. The debate focused mainly on the second-generation antipsychotics. The analysis of the scientific literature indicates however that this discussion is not recent and an increase of diabetes prevalence in schizophrenic populations was already described before the introduction of neuroleptics. Then, after the introduction of the first neuroleptics in the 1950s, an increase of diabetes prevalence was reported among treated patients and the same alarms occurred in the 1990s after the introduction of second-generation antipsychotics. These treatments were related to an increase of glucose tolerance impairment, type II diabetes and diabetic acidoketosis. Recent epidemiological studies have confirmed the increase prevalence of diabetes in schizophrenic patients, particularly in schizophrenic patients before any antipsychotic treatment. Among the suggested mechanisms, there are sedentary life (due to hospitalisation and sedative effects of neuroleptics), food imbalance, shared genetic factors for diabetes and schizophrenia. Moreover, the frequency of the metabolic syndrome is increased in schizophrenic populations. This syndrome associates blood glucose increase, lipid metabolism disorders and android obesity. This could explain--via an increase of the cortisol production--the increase of mortality due to cardiovascular diseases observed in schizoprhenic patients. Thus, it seems well established that schizophrenia is associated with an increased risk for diabetes. It is however more difficult to evaluate the role of antipsychotic treatment as a causative factor of diabetes. Indeed, there are many published case reports or diabetes or diabetic acidoketosis after an antipsychotic treatment, but the level of evidence in controlled trials is low. Many studies were performed on large databases, but were retrospective and subjected to many flaws: concomitant diseases not taken into account, diabetes status evaluated by drug consumption, unknown diabetes status before antipsychotic treatment, etc. In the few prospective studies performed, no significant differences between the atypical versus typical antipsychotics were evidenced for new cases of diabetes. Moreover, in general population, the glucose tolerance impairment is underdiagnosed and it is estimated that people with a glucose tolerance impairment have a 5-10% annual risk of type II diabetes. Thus, this concern has to be replaced among the world epidemic increase of diabetes and in a population of patients whose the disease itself and life style are risk factors for diabetes. Some studies have explored the pathophysiological mechanisms that could support a diabetogenic effect of antipsychotics. Although it does not seem to be a direct effect of antipsychotics on insulin secretion by pancreatic cells, body weight increase has been evidence for both typical and atypical antipsychotics. However, it remains unclear whether this weight increase is responsible for a visceral adiposity, which is a risk factor better fitted to the cardiovascular mortality tha the body weight itself. Other hypotheses involving an effect on the leptin, which regulates the appetite, have been proposed. In waiting of new prospective controlled studies, and without denying the impact of antipsychotics on the glucose and lipid metabolisms (on the weight increase, for example), it should be recognized that the benefit/risk ratio remains largely in favour of the treatment, particularly for the atypical antipsychotics, more effective and better tolerated at the neurological level than the conventional antipsychotics. One of the benefits of the mainly articles in professional media about this concern is to draw attention on the metabolism disorders in schizophrenic patients, which are important risk factor of their frequent cardiovascular surmortality whatever the causes. Consequently, it is advised to monitor glucose and lipid metabolisms of schizophrenic patients before and during their treatment (body weight, fast blood glucose, blood cholesterol and triglycerides). In conclusion, schizophrenic patients are a population with an increased metabolic risk, which is a cause of their increased mortality. Although these data are known since a long time ago, this population does not benefit from the same metabolic follow-up than the non-schizophrenic population. The debate on the possible relationship between diabetes and antipsychotics should be also taken as a helpful recall of the necessity to follow simple rules of prevention and monitoring in this at-risk population. This should make it possible to preserve the benefit of the antipsychotics, the contribution of which in the treatment of schizophrenia is not any more to demonstrate.

Evidence of basal pituitary-adrenal overactivity in first episode, drug naïve patients with schizophrenia

BACKGROUND

Evidence for basal hypothalamic-pituitary-adrenal (HPA) axis dysfunction in schizophrenia is less consistent than that seen in major depression. Potential reasons include sampling procedures and the use of patients on antipsychotic medications which may suppress the HPA axis. Therefore, the objective of this study was to determine whether first episode, drug naïve patients with schizophrenia have evidence of basal HPA axis dysfunction by measuring plasma levels of AVP, ACTH and cortisol from 13:00 to 16:00 h, a time frame which is believed to reflect 24 h concentrations of HPA axis activity.

METHOD

In this cross-sectional study, plasma levels of AVP, ACTH and cortisol were measured in 12 (7 males and 5 females) (mean age +/-SD=33.6+/-12.6 years) patients with DSM-IV schizophrenia and compared with those found in age- and sex-matched healthy controls.

RESULTS

Patients and controls did not differ in terms of their 13:00 h cortisol and AVP. However, patients with schizophrenia had higher levels of ACTH as compared to control subjects at 13:00 h (41.3+/-14.6 vs. 12.4+/-1.1 pg/ml respectively; t=1.99, df=11, p <0.05). In comparison to controls subjects, patients with schizophrenia, had higher mean (+/-SE) AUC of ACTH (26.3+/-6.2 vs. 13.9 nmol/l, respectively; t=2.86, df=11, p <0.02) and cortisol (279.4+/-26.0 vs. 213.1+/-18.4 nmol/l, respectively; t=3.72, df=11, p <0.01). Though, patients with schizophrenia, in comparison to control subjects, had lower mean (+/-SE) AUC of AVP (0.87+/-0.24 vs. 1.42+/-0.34 pmol/l, respectively; t=2.29, df=11, p <0.02).

CONCLUSIONS

First episode, drug naïve patients with schizophrenia show evidence of basal overactivity of the pituitary-adrenal axis.

Effects of acute metabolic stress on the dopaminergic and pituitary-adrenal axis activity in patients with schizotypal personality disorder

BACKGROUND

Stress has been associated with the onset of schizophrenia and exacerbation of psychotic symptoms. Patients with schizotypal personality disorder (SPD), the prototypic schizophrenia spectrum disorder, do not develop the frank psychosis of schizophrenia and appear clinically to be less reactive to stress than schizophrenic patients. Schizophrenic patients demonstrate increased dopaminergic (DA) and hypothalamic-pituitary-adrenal-axis (HPA) activation following 2-deoxyglucose (2-DG), an acute metabolic (glycopyruvic) stressor, compared to healthy volunteers (HV). We hypothesized that SPD patients would demonstrate comparable or lower DA and HPA responses after 2-DG to HV.

METHODS

Fifteen SPD patients and 13 HV were administered 2-DG (40 mg/kg, i.v.) in a double-blind, placebo-controlled, randomized protocol. The area under the curve (AUC) was determined for plasma HVA, ACTH and cortisol (utilizing baseline and post infusion indices).

RESULTS

2-DG induced significant increases in ACTH, cortisol and HVA concentrations in both groups and cortisol elevations were significantly lower in patients with SPD than in HV.

CONCLUSIONS

Patients with SPD have a blunted cortisol and a normal dopaminergic response to 2-DG. These results are consistent with the hypothesis that SPD patients are better buffered against DA and HPA overactivation in response to stress.

Metabolic disturbance in first-episode schizophrenia

BACKGROUND

Schizophrenia shortens life, e.g. through suicide and obesity-related diseases such as type 2 diabetes mellitus. It is assumed that medications play a major role, but most of the evidence for this comes from studies poorly controlled for variables such as lifestyle and medication status.

AIMS

To determine whether schizophrenia is associated (independently of medication) with the development of certain metabolic disturbances and whether these might be explained by stress axis dysfunction.

METHOD

Literature review.

RESULTS

Most studies did not control for confounding factors such as previous usage of medication, lifestyle, age and ethnicity. A few conducted in drug-naïve patients with first-episode schizophrenia appear to indicate that these patients have higher than expected rates of visceral obesity and impaired fasting glucose concentrations, which may be related to a subtle disturbance of the hypothalamic-pituitary-adrenal axis.

CONCLUSIONS

Schizophrenia is independently associated with physical illnesses that have a metabolic signature. Therefore, patients need to have a thorough physical assessment at diagnosis and at regular intervals thereafter. Metabolic disturbances have been found in drug-naïve patients with first-episode illness and may be an inherent part of the illness.

Nutritional manipulation and psychiatric conditions: focus on mood and cognition

In this paper, several experimental models of human depression and cognitive dysfunction, which are designed specifically to mimic the proposed mechanisms of action of many nutritional supplements, are illustrated. These mechanisms of interest are antioxidant effects, glucose utilization, neuronal membrane function and neurotransmitter effects, with particular reference to nutrient-based amino acid manipulations of neurotransmission, such as tryptophan depletion. It is concluded that the application of experimental human models of altered mood and cognitive function may illuminate substantially the quest for nutritional enhancement of human mood and cognitive function.

Olanzapine and clozapine increase the GABAergic neuroactive steroid allopregnanolone in rodents

The neuroactive steroid allopregnanolone is a potent gamma-aminobutyric acid type A (GABA(A)) receptor modulator with anxiolytic and anticonvulsant effects. Olanzapine and clozapine also have anxiolytic-like effects in behavioral models. We therefore postulated that olanzapine and clozapine would elevate allopregnanolone levels, but risperidone and haloperidol would have minimal effects. Male rats received intraperitoneal olanzapine (2.5-10.0 mg/kg), clozapine (5.0-20.0 mg/kg), risperidone (0.1-1.0 mg/kg), haloperidol (0.1-1.0 mg/kg), or vehicle. Cerebral cortical allopregnanolone and peripheral progesterone and corticosterone levels were determined. Adrenalectomized animals were also examined. Both olanzapine and clozapine increased cerebral cortical allopregnanolone levels, but neither risperidone nor haloperidol had significant effects. Olanzapine and clozapine also increased serum progesterone and corticosterone levels. Adrenalectomy prevented olanzapine- and clozapine-induced elevations in allopregnanolone. Allopregnanolone induction may contribute to olanzapine and clozapine anxiolytic, antidepressant, and mood-stabilizing actions. Alterations in this neuroactive steroid may result in the modulation of GABAergic and dopaminergic neurotransmission, potentially contributing to antipsychotic efficacy.

Physical consequences of schizophrenia and its treatment: the metabolic syndrome

Schizophrenia is a life shortening illness. Unnatural causes and natural causes are put forward as reasons for this excess mortality. In terms of the latter, a host of different physical disorders occur with increased frequency in schizophrenia. When taken together, some of these illnesses such as type 2 diabetes mellitus and cardiovascular disorders constitute the Metabolic Syndrome; a characteristic phenotype of those with this syndrome is excessive visceral fat distribution. The exact reasons why this particular syndrome occurs in schizophrenia is as yet unclear though factors such as life style, poor diet and lack of exercise may contribute to it's development. Alternatively, overactivity of the hypothalamic-pituitary-adrenal axis leading to hypercortisolaemia can also result in excessive visceral fat accumulation. This minireview aims to explore the potential role of these issues and medication in terms of the increased morbidity and mortality observed in schizophrenia.

Stress in schizophrenia: an integrative view

Stress and the development of a (schizophrenic) psychosis are inextricably related. The process by which stress actually affects psychosis is far less clear. The hypothalamic-pituitary-adrenal system, and in particular the release of corticosteroids, has been attributed an essential role. However, schizophrenia is a disorder in which many functions are distorted. Dysfunctions can be found in behavior, cognition, coping, physiology, pituitary-adrenal and immune functioning. In this short paper, these functions are discussed as to how they contribute to the way stress is appraised and processed. Schizophrenic patients are impaired in their biological response to stress by showing a blunted cortisol response to psychosocial stress. It is hypothesized that this reflects rather cognitive dysfunction, based on biological dysfunctions in those brain structures that are responsible for these processes, i.e. the prefrontal cortex and the limbic system. Considering the blunted cortisol response as a maladaptive stress response, its consequences are commented on with an emphasis on the immune system. Finally, the role of neuroleptics, and in particular the atypical ones, is discussed for their beneficial effect, beyond their fear-and anxiety-reducing properties, in restoring some of the cognitive dysfunctions schizophrenic patients display. By doing so, they may improve perception of the environment, enhance adjustment and thus a proper stress response. Integration of these processes in stress research described, may provide new vistas of the stress concept in schizophrenia.

Pituitary-adrenal and parasympathetic function in chronic schizophrenic patients with postoperative ileus or hypotension

We studied the relationship between parasympathetic, sympathetic and pituitary-adrenal functions in chronic schizophrenic patients with complications such as postoperative paralytic ileus and hypotension during anaesthesia. Plasma epinephrine, norepinephrine (NE), adrenocorticotropin (ACTH), cortisol and the coefficient of variation (CV) of the R-R intervals on the electrocardiogram (ECG) as parasympathetic parameter were measured in schizophrenic and control patients. The CV value of the R-R interval on the ECG before the start of anaesthesia was significantly decreased to 2.3 +/- 0.2 in the schizophrenic patients as compared with 3.5 +/- 0.3 of the control patients. The CV value of the R-R interval on the ECG in schizophrenic patients with postoperative paralytic ileus was more diminished to 1.6 +/- 0.2. The CV values in schizophrenic patients with and without hypotension during anaesthesia were similar and we could not find any significant difference. Chronic schizophrenic patients developed a decrease in NE, ACTH and cortisol responses to surgical stress, while there were no significant differences in these hormonal changes between those patients with and without paralytic ileus and hypotension during anaesthesia. In conclusion, the CV value of the ECG R-R interval may be correlated inversely with the expectancy of postoperative ileus in chronic schizophrenic patients. Their suppressed pituitary-adrenal function and sympathetic system may be indirectly associated with the paralytic ileus and hypotension.

Psychoneuroendocrinology of schizophrenia

The study of psychoneuroendocrinology of schizophrenia has yielded an extensive but inconclusive body of data. Investigations to date have been limited by several factors, including the confounding effects of neuroleptic drugs, methodological limitations, and lack of appreciation for the heterogeneity of the illness. Previously, the focus of research has been on the measurement of anterior pituitary hormones, guided by the assumptions that these hormones are regulated by the central nervous system (CNS) to a significant degree and that the unique anatomic relationship of the pituitary gland to the hypothalamus and the CNS is potentially relevant. Patients with schizophrenia do appear to have distinct endocrinologic profiles. However, although the hormonal differences between patients with schizophrenia and the general population appear to be subtle in magnitude. Nonetheless, investigation, and the exploration of the possible effect of gonadal and posterior pituitary hormones merits particular attention.

Effects of acute metabolic stress on plasma progesterone and testosterone in male subjects: relationship to pituitary-adrenocortical axis activation

Stress effects on progesterone and testosterone as well as the relationship of these effects to the hypothalamic-pituitary-adrenal (HPA) axis activation have been extensively investigated in laboratory animals. There is less information about the impact of stress on sex steroids in humans. The purpose of the present study was to examine the influence of acute arterial levels of progesterone, testosterone, adrenocorticotropic hormone (ACTH), cortisol, gonadotropins and sex hormone binding globulin (SHBG) in healthy male subjects. The stressor used was glucoprivation induced by pharmacological doses of 2-deoxy-D-glucose (2DG) (40mg/kg). This stress resulted in increases in progesterone, decreases in testosterone and no significant change in gonadotropins or SHBG. ACTH and cortisol were robustly elevated and these elevations related significantly to changes in progesterone but not testosterone. The implications of these data for the understanding of the role of sex steroids in the stress response is discussed.

Abstinent alcoholics exhibit an exaggerated stress response to 2-deoxy-D-glucose challenge

Chronic excessive alcohol consumption can significantly disturb the hypothalamic control of glucose metabolism; however, the mechanism and clinical significance of this disturbance are poorly understood. We used 2-deoxy-D-glucose (2-DG), which produces intracellular glucoprivation, to compare neurochemical, physiological, and behavioral responses to glucoprivic stress between alcoholics abstinent for 3 weeks and healthy volunteers. Twenty-six male alcoholics and 15 male healthy volunteers received intravenous infusions of placebo, 12.5 mg/kg, and 25.0 mg/kg of body weight of 2-DG over 30 min on three separate days, following a random-ordered, double-blind procedure. Minimal effects were observed following administration of the 12.5 mg/kg of body weight dose of 2-DG. Following 25.0 mg/kg, alcoholics showed both exaggerated ACTH and cortisol responses and greater increases in caloric intake when compared with controls. Although anxiety, desire to consume alcohol, plasma progesterone, and sympathetic and adrenal medullary activity all increased following 2-DG, these responses did not differ between alcoholics and controls. The present findings suggest certain specificity for the exaggerated hypothalamic and adrenocortical responses to mild glucoprivic stress in 3-week-abstinent alcoholics.