Blunted ACTH response to hypoglycemic stress in depressed patients but not in patients with schizophrenia

Hypothalamic-pituitary-adrenocortical axis: neuropsychiatric aspects

Evidence of aberrant hypothalamic-pituitary-adrenocortical (HPA) activity in many psychiatric disorders, although not universal, has sparked long-standing interest in HPA hormones as biomarkers of disease or treatment response. HPA activity may be chronically elevated in melancholic depression, panic disorder, obsessive-compulsive disorder, and schizophrenia. The HPA axis may be more reactive to stress in social anxiety disorder and autism spectrum disorders. In contrast, HPA activity is more likely to be low in PTSD and atypical depression. Antidepressants are widely considered to inhibit HPA activity, although inhibition is not unanimously reported in the literature. There is evidence, also uneven, that the mood stabilizers lithium and carbamazepine have the potential to augment HPA measures, while benzodiazepines, atypical antipsychotics, and to some extent, typical antipsychotics have the potential to inhibit HPA activity. Currently, the most reliable use of HPA measures in most disorders is to predict the likelihood of relapse, although changes in HPA activity have also been proposed to play a role in the clinical benefits of psychiatric treatments. Greater attention to patient heterogeneity and more consistent approaches to assessing treatment effects on HPA function may solidify the value of HPA measures in predicting treatment response or developing novel strategies to manage psychiatric disease.

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.

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.

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.

Relationship between cortisol responses to stress and personality

Although there is growing evidence of links between the cortisol stress response and personality, the nature of the relationships and the underlying mechanisms require further clarification. The purpose of this study was to examine associations between personality traits and cortisol responses to stress using the Revised NEO Personality Inventory five-factor model of personality. In total, 68 healthy adults, aged 18-30 years, completed the personality assessment and underwent a laboratory psychological stress test that consisted of a 5 min speech and 5-min of mental arithmetic. Findings showed that in the sample as a whole, less Openness was associated with lower cortisol responses to the challenge. Cortisol responses also corresponded to certain personality dimensions in a gender-specific manner. Blunted cortisol responses were associated with higher Neuroticism in women and with lower Extraversion in men. These findings suggest that personality traits that have been traditionally associated with greater psychopathology were also associated with blunted HPA axis responses to stress.

Subchronic treatment with amino acid mixture of L-lysine and L-arginine modifies neuroendocrine activation during psychosocial stress in subjects with high trait anxiety

The aim of the present study was to evaluate possible modulatory effect of the treatment with L-lysine and L-arginine on neuroendocrine activation during psychosocial stress in healthy subjects with relatively high trait anxiety in a randomized, double blind placebo controlled trial. In 29 healthy subjects at the upper limit of the normal range of a trait anxiety scale, a mixture of L-lysine and L-arginine (3 g each/day) was administered for 10 days followed by exposure to a psychosocial stress procedure based on public speech. Hormone levels, cardiovascular activation and skin conductance were measured. Amino acid treatment resulted in enhanced adrenocorticotropic hormone, cortisol, adrenaline and noradrenaline levels and galvanic skin responses during stress compared to those in placebo-treated group. Increases in the heart rate and blood pressure in response to public speaking task were not influenced by amino acid treatment. Results of the present study support the hypothesis that L-lysine in combination with L-arginine, which may induce anxiolytic effects, modify hormonal responses during psychosocial stress in humans. Such action may represent a normalization of hormone levels to the pattern observed previously in subjects with low trait anxiety.

Chronic ACTH autoantibodies are a significant pathological factor in the disruption of the hypothalamic-pituitary-adrenal axis in chronic fatigue syndrome, anorexia nervosa and major depression

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is a commonly recognized feature of many pathological conditions. Abnormal adrenal responses to experimental manipulation have been well documented in patients suffering from chronic fatigue syndrome, anorexia nervosa and major depression. Yet no defect of any single organ, gland or brain region has been identified as a cause of these abnormalities. The disruption of the HPA axis that occurs in these conditions can be understood if an interfering factor is present in these patients. Evidence indicates that this interfering factor is adrenocorticotropin hormone (ACTH) autoantibodies. Chronic high levels of ACTH autoantibodies will significantly disrupt the HPA axis and force the body to compensate for an impaired cortisol response. The resulting effect of chronic ACTH autoantibody interference is the manifestation of adrenocortical insufficient symptoms and psychological disturbances. Some symptoms of chronic fatigue syndrome, anorexia nervosa and major depression, such as anxiety, are the adverse effects of mechanisms compensating for less effective ACTH due to autoantibodies. Furthermore, these patients engage in extraordinary behaviors, such as self-injury, to increase their cortisol levels. When this compensation is inadequate, symptoms of adrenocortical insufficiency appear. Corticosteroid supplements have been demonstrated to be an effective treatment for chronic fatigue syndrome, anorexia nervosa and major depression. It allows the patients to have the corticosteroids they require for daily functioning and daily stressors. This therapy will relieve the patients of their symptoms of adrenocortical insufficiency and permit their cortisol-stimulating mechanisms to operate at levels that will not cause pathological problems.

Low GSK-3beta in schizophrenia as a consequence of neurodevelopmental insult

Glycogen synthase kinase-3 (GSK-3) is a protein kinase highly abundant in brain and involved in signal transduction cascades, particularly neurodevelopment. Its activity and protein levels have been reported to be over 40% lower in postmortem frontal cortex of schizophrenic patients. GSK-3beta in occipital cortex of schizophrenic patients was not reduced, suggesting regional specificity. There was no reduction in GSK-3beta protein levels in fresh and immortalized lymphocytes and both GSK-3 activity and GSK-3beta mRNA levels in fresh lymphocytes from schizophrenic patients. In the schizophrenia-related neonatal ventral hippocampal lesion rat model, we measured GSK-3beta protein levels and GSK-3 activity in the frontal cortex. GSK-3beta protein levels in lesioned rats were significantly lower than in sham rats, favoring perinatal insult as a cause of low GSK-3beta in schizophrenia. Taken together, these studies suggest that low GSK-3 in postmortem brain of schizophrenic patients is a late consequence of perinatal neurodevelopmental insult in schizophrenia. In rats, acute or chronic cold restraint stress did not change GSK-3beta protein levels. Chronic treatment of rats with lithium, valproate, haloperidol or clozapine did not change rat cortical GSK-3beta protein levels ex vivo, supporting the concept that low GSK-3beta in schizophrenia is not secondary to stress or drug treatment. Our initial findings of low GSK-3beta protein levels in postmortem brain have been replicated by another group. Our own group has found additionally that GSK-3beta mRNA levels were 40% lower in postmortem dorsolateral prefrontal cortex (DLPFC) of schizophrenic patients, supporting our previous findings. Further studies will be aimed at determining whether nonspecific neonatal damage or only specific factors cause low GSK-3 as a late effect. We plan to study whether low GSK-3beta activity is associated with biochemical effects such as elevated beta-catenin levels.

High trait anxiety in healthy subjects is associated with low neuroendocrine activity during psychosocial stress

Altered stress responsiveness has been repeatedly related to mood and anxiety disorders. In a traditional view, a reduction of the stress response has been thought favorable. The goal of the present study was to verify the hypothesis that high anxiety is accompanied by enhanced hormone release during stress. Healthy subjects at the upper (anxious, n = 15) and lower (non-anxious, n = 12) limits of the normal range of a trait anxiety scale (State trait anxiety inventory) were exposed to psychosocial stress procedure based on public speech. Hormone levels, cardiovascular activation and skin conductance were measured. Exposure to psychosocial stress was associated with significant increases of all parameters measured. During the stress procedure, subjects with high trait anxiety exhibited lower levels of hormones of the hypothalamo-pituitary-adrenocortical axis, namely ACTH and cortisol in plasma, as well as cortisol in saliva. Similarly, the stress-induced activation of epinephrine, norepinephrine and prolactin secretion was significantly lower in anxious subjects in comparison with that in non-anxious subjects. Thus, in contrast to the traditional view, high anxiousness was not associated with exaggerated stress response. Our findings suggest that high trait anxiety may be associated with an inability to respond with adequate hormone release to acute stress stimuli.

Behavioral and Neuroendocrine Changes during Mental Stress and Repeated Treatment with Antidepressants in Healthy Men

Excessive stress loadings in daily life are believed to play a role in the development of affective disorders. Our recent finding of enhanced neuroendocrine activation during stress of hypoglycemia after repeated antidepressant treatment in healthy men supports the hypothesis that the clinical effects of antidepressant treatment may be partly due to the adjustment of the stress response, which was reported to be blunted in depressive patients. The present double-blind placebo-controlled study investigated the effects of 6 days of treatment with the antidepressants citalopram or tianeptine on neuroendocrine activation during mental stress. Blood pressure, heart rate, and salivary cortisol values were measured. The stress procedure, lasting 17 min, consisted of a short intelligence test followed by the Stroop word-color interference test. Citalopram treatment was associated with a significant enhancement of stress-related increase in systolic and diastolic blood pressure. No differences were observed in the heart rates and salivary cortisol. Comparisons based on cluster analysis revealed that subjects with poor performance in the Stroop test displayed a significantly lower rise of systolic and diastolic blood pressure values after the stress procedure and lower prestress cortisol levels in saliva when compared to the good performing subjects. Our findings show that antidepressant treatment can enhance the neuroendocrine response also during mental stress, and suggest that mental performance during stress is related to the pattern of cardiovascular and adrenocortical activation.

Immunity and schizophrenia: autoimmunity, cytokines, and immune responses

As is evident from the present account, there is no single or persuasive argument that signals emanating from the immune system are directly involved in the etiology of schizophrenia. We do not even know if we are dealing with a single disorder with a single causality; almost certainly we are not. The precise etiology of schizophrenia, as with so many neurological disorders, remains obscure. However, there is abundant evidence in schizophrenia of mutual dysregulation of neuronal function and immune system activity. Although this evidence is not always consistent, a pattern emerges suggesting aspects of immune activity being involved in the pathology of neuronal development that characterizes schizophrenia. Exposure to infective agents, HLA associations, autoimmune associations, disturbances in lymphocyte populations, and cytokine imbalances with a skew toward Th2 activity are supportive of this view. That the evidence is not always consistent is a testament to the complexity and heterogeneity of the disorder, to confounding by antipsychotics that themselves are immunomodulatory, and to the multifaceted nature, with all its checks and balances, of the immune system itself.

Lack of effect of acute, subchronic, or chronic stress on glycogen synthase kinase-3beta protein levels in rat frontal cortex

Glycogen synthase kinase (GSK)-3beta is a conserved serine/threonine protein kinase highly abundant in brain tissue. A dominant mechanism by which cells react to stress involves GSK-3beta. We studied the effect of stress on GSK-3beta levels ex vivo. We have previously found reduced GSK-3beta protein levels and GSK-3 activity in postmortem prefrontal cortex of schizophrenic patients. Since schizophrenic patients experience stress more severely than healthy people, we questioned whether their GSK-3beta reduction is stress-related using a rat model. Rats were exposed to acute, subchronic, or chronic stress using brief cold restraint. No effect was found on frontal cortex GSK-3beta protein levels. These results suggest that reduction in GSK-3beta levels in schizophrenic patients is not affected by cold restraint stress and supports the possibility that the changes observed in postmortem brains may be related to the disease.

Enhancement of stress-induced pituitary hormone release and cardiovascular activation by antidepressant treatment in healthy men

A randomized, double-blind, placebo-controlled trial was performed to verify the suggestion that (i) in accordance with the results of animal studies, treatment with antidepressants inhibits hormone release in response to stressful stimulation in humans and (ii) drugs with opposing effects on brain serotonine (citalopram and tianeptine) exert similar modulatory effects on neuroendocrine activation during stress. Healthy male volunteers were treated with citalopram (20 mg), tianeptine (37.5 mg) or placebo for 7 days. As a stress stimulus, insulin-induced hypoglycaemia was used. Measurement of hormone concentrations revealed an enhanced release of adrenocorticotropic hormone and growth hormone in response to stress of hypoglycaemia in subjects treated with both antidepressants used. A similar augmentation was observed in systolic blood pressure. Stress-induced prolactin release was potenciated by citalopram only. Plasma renin activity, epinephrine, norepinephrine and cortisol levels failed to be modified by antidepressants. The present study demonstrates that (i) repeated antidepressant treatment in healthy men does not inhibit, but enhances, neuroendocrine activation during stress and (ii) such effects were observed after treatment with antidepressants having opposing actions on brain serotonin, indicating involvement of nonserotoninergic mechanisms.

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.

Inhibition of the cortisol response to surgical stress in chronically depressed patients

STUDY OBJECTIVE

To evaluate whether the pituitary-adrenal and catecholamine response to surgical stress is modified in chronically depressed patients.

DESIGN

Prospective, controlled study.

PATIENTS

25 ASA physical status I and II depressed patients taking chronic antidepressant therapy and 25 control patients undergoing orthopedic surgery of the extremities.

INTERVENTIONS

All patients received anesthesia induction with thiopental 5 mg/kg and suxamethonium 1 mg/kg intravenously (IV) and were maintained with 1.5% to 2.0% isoflurane in nitrous oxide (70%) and oxygen (30%).

MEASUREMENTS AND MAIN RESULTS

Plasma cortisol concentration (27.7 +/- 3.6 microg/dL) in chronic depressed patients at 60 minutes after the skin incision was not significantly higher than that (23.9 +/- 2.7 microg/dL) before the induction, although plasma cortisol concentration in the control group significantly increased. Plasma norepinephrine concentration at 60 min after the skin incision in depressed patients with more symptoms of depression was significantly higher than that of patients with less symptoms of depression.

CONCLUSION

The cortisol response to surgical stress in depressed patients was inhibited and norepinephrine response to surgical stress was increased in depressed patients with more symptoms of depression.

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.

CRH challenge test in anxious depression

Recently, renewed interest has developed in the concept of anxious depression. Using an operational definition of "anxious depression" based on the SADS interview, 25 patients with major depressive disorder were separated into anxious (n = 14) and nonanxious (n = 11) subtypes. These two patient groups and normal control subjects received an intravenous corticotropin-releasing hormone challenge test. Adrenocorticotropic hormone (ACTH) and cortisol responses were compared among the three groups. Patients with anxious depression had significant attenuation of ACTH response when compared to nonanxious patients and normal control subjects.

Imipramine effect on hypothalamic-pituitary-adrenal axis response to hypoglycemia

Six control subjects underwent an insulin tolerance test before and after the administration of therapeutic doses of imipramine hydrochloride for 10 days to investigate effects of tricyclic antidepressants on hypothalamic-pituitary-adrenal axis response to hypoglycemia. The mean steady-state tricyclic blood level was 141 (SD = 66) ng/ml. Baseline levels of glucose, cortisol, and adrenocorticotropic hormone (ACTH) were not affected by the administration of imipramine. After administration of imipramine for 10 days, subjects uniformly had a significantly lower glucose nadir than before its administration (before imipramine: mean = 32 mg/dl; SD = 5; after imipramine: mean = 24 mg/dl; SD = 6). There was no difference in ACTH or cortisol response before and after the administration of imipramine. These findings suggest that imipramine hydrochloride increases sensitivity to the hypoglycemic effects of insulin, but does not alter the counterregulatory response of ACTH and cortisol.