Systemic hormonal and physiological abnormalities in anxiety disorders

Role of synthetical amynoquinone ethyl 2-(1,4-dioxo-1,4-dihydronaphthalen-2-ylamino) acetate in inhibition of Ehrlich's tumor

Quinones are naturally or synthetically occurring secondary metabolites that have various bio-dynamics, highlighting their antitumor potential. This has been explored through their selective cytotoxicity, and studies in medicinal chemistry about the relation between biological activity versus chemical structure may lead to the solution of the toxicity problems associated with quinones. In this context, the antitumor effect of a synthetic naphthoquinone, named Ethyl 2-(1,4-Dioxo-1,4-Dihydronaphthalen-2-Ylamino) Acetate, was tested using mice transplanted with Ehrlich ascitic tumor as an experimental model. The acute toxicity test was performed using 30 mice that received the aminoquinone at doses of 100, 200, 300, and 600 mg/kg. After evaluation of the clinical findings in the spontaneous activity tests, the LD50 calculation for the test substance showed low levels of toxicity at doses lower than 244.11 ± 23.29 mg/kg. Thus, three experimental groups were established, where animals transplanted with tumor cells received NaCl vehicle solution (control, n = 6), and the others were treated with 71.7 mg/kg of Methotrexate (n = 6) or 20 mg/kg of Aminoquinone (n = 6). All administrations were intraperitoneal, in a single dose. Three days after the implantation of the tumor cells the animals were weighed daily and evaluated for tumor biometry and development. The treatments occurred five days after the implantation of the tumor cells and were extended for 7 more days. At the end of the 12-day experimental period, all animals were euthanized for biochemical and histopathological analyses of the tumors and vital organs. The spontaneous activity test showed that the amount of responses associated with the nervous system tends to increase with the increase in dosage, highlighting the excitatory effect on the central nervous system in almost all dosages employed, followed by depressant activities on this system. There was a significant tumor reduction, both in animals treated with methotrexate (71.7 %) and in those treated with aminoquinone (91.6 %) in the control group. There was no significant difference in tumor volume between the animals treated with aminoquinone or methotrexate. The histopathological analysis revealed that in both treatments there were fewer mitoses in the tumor mass compared to the control group. However, there was apparent toxicity to the liver, heart, and left kidney in the treatment with methotrexate compared to aminoquinone. The significant capacity for tumor reduction presented by aminoquinone allows pointing it as a promising alternative for the development of a more efficient drug to control tumor development, being necessary for the development of new studies to deepen the knowledge about its mechanisms of action.

Flavopiridol Protects against Fungal Keratitis due to Aspergillus fumigatus by Alleviating Inflammation through the Promotion of Autophagy

Fungal keratitis is a serious infectious keratopathy related to fungal virulence and excessive inflammatory responses. Autophagy exhibits a potent ability to resolve inflammation during fungal infection. This study aimed to investigate the protective function of flavopiridol in Aspergillus fumigatus keratitis and explore its effects on autophagy. In our study, the corneas of the fungal keratitis mouse model were treated with 5 μM flavopiridol. In vitro, RAW 264.7 cells were pretreated with 200 nM flavopiridol before fungal stimulation. A. fumigatus was incubated with flavopiridol, and the antifungal activity of flavopiridol was detected. Our results indicated that flavopiridol treatment notably reduced clinical scores as well as cytokines expression of infected corneas. In infected RAW 264.7 cells, flavopiridol treatment inhibited IL-1β, IL-6, and TNF-α expression but promoted IL-10 expression. Transmission electron microscopy (TEM) images showed that more autolysosomes were present in infected corneas and RAW 264.7 cells after flavopiridol treatment. Flavopiridol treatment notably upregulated the protein expression of LC3, Beclin-1, and Atg-7. 3-Methyladenine (3-MA, an inhibitor of autophagy) pretreatment counteracted the cytokine regulation induced by flavopiridol. Moreover, flavopiridol promoted the phagocytosis of RAW 264.7 cells. Flavopiridol also exhibited antifungal activity by restricting fungal growth and limiting fungal biofilm formation and conidial adhesion. In conclusion, flavopiridol significantly alleviated the inflammation of fungal keratitis by activating autophagy. In addition, flavopiridol promoted the phagocytosis of RAW 264.7 cells and exhibited antifungal function, indicating the potential therapeutic role of flavopiridol in fungal keratitis.

How Microbes Affect Depression: Underlying Mechanisms via the Gut-Brain Axis and the Modulating Role of Probiotics

Accumulating evidence suggests that the gut microbiome influences the brain functions and psychological state of its host via the gut-brain axis, and gut dysbiosis has been linked to several mental illnesses, including major depressive disorder (MDD). Animal experiments have shown that a depletion of the gut microbiota leads to behavioral changes, and is associated with pathological changes, including abnormal stress response and impaired adult neurogenesis. Short-chain fatty acids such as butyrate are known to contribute to the up-regulation of brain-derived neurotrophic factor (BDNF), and gut dysbiosis causes decreased levels of BDNF, which could affect neuronal development and synaptic plasticity. Increased gut permeability causes an influx of gut microbial components such as lipopolysaccharides, and the resultant systemic inflammation may lead to neuroinflammation in the central nervous system. In light of the fact that gut microbial factors contribute to the initiation and exacerbation of depressive symptoms, this review summarizes the current understanding of the molecular mechanisms involved in MDD onset, and discusses the therapeutic potential of probiotics, including butyrate-producing bacteria, which can mediate the microbiota-gut-brain axis.

CD36 deficiency affects depressive-like behaviors possibly by modifying gut microbiota and the inflammasome pathway in mice

Both inflammatory processes and gut microbiota have been implicated in the pathophysiology of depressive disorders. The class B scavenger receptor CD36 is involved in the cytotoxicity associated with inflammation. However, its role in depression has not yet been examined. In this study, we investigated whether CD36 affects depression by modulating the microbiota-gut-inflammasome-brain axis. We used CD36^-/- (knockout) mice subjected to chronic social defeat stress, and measured the expression of CD36 in these depressed mice and in patients with depression. The hippocampus of CD36^-/- mice was used to investigate changes in the NLRP3 inflammasome signaling pathway. The 16S rRNA gene sequence-based approach was used to compare the cecal microbial communities in CD36^-/- and WT mice. The CD36 deficiency in CD36^-/- mice alleviated chronic stress-induced depression-like behaviors. CD36 was upregulated in depressed mice as well as in depressed patients. Furthermore, the NLRP3 inflammasome signaling pathway was downregulated in the hippocampus of CD36^-/- mice. The Simpson Diversity Index revealed increased cecal bacterial alpha-diversity in the CD36^-/- mice. Among genera, Bacteroides, Rikenella, and Alloprevotella were significantly more abundant in the CD36^-/- mice, whereas Allobaculum was less abundant, consistent with the attenuated inflammation in the hippocampus of CD36^-/- mice. Our findings suggest that CD36 deficiency changes the gut microbiota composition, which in turn may impact depressive-like behaviors by affecting the inflammasome pathway.

Honokiol Reduces Fungal Load, Toll-Like Receptor-2, and Inflammatory Cytokines in Aspergillus fumigatus Keratitis

Purpose

We characterized the effects of Honokiol (HNK) on Aspergillus fumigatus-caused keratomycosis and the underlying mechanisms. HNK is known to have anti-inflammatory and antifungal properties, but the influence on fungal keratitis (FK) remains unknown.

Methods

In ex vivo, minimum inhibitory concentration and Cell Count Kit-8 assay were carried out spectrophotometrically to provide preferred concentration applied in vivo. Time kill assay pointed that HNK was fungicidal and fungistatic chronologically. Adherence assay, crystal violet staining, and membrane permeability assay tested HNK effects on different fungal stages. In vivo, clinical scores reflected the improvement degree of keratitis outcome. Myeloperoxidase (MPO) assay, flow cytometry (FCM), and immunohistofluorescence staining (IFS) were done to evaluate neutrophil infiltration. Plate count detected HNK fungicidal potentiality. RT-PCR, Western blot, and enzyme-linked immunosorbent assay (ELISA) verified the anti-inflammatory activity of HNK collaboratively.

Results

In vitro, MIC90 HNK was 8 µg/mL (no cytotoxicity), and Minimal Fungicidal Concentration (MFC) was 12 µg/mL for A. fumigatus. HNK played the fungistatic and fungicidal roles at 6 and 24 hours, respectively, inhibiting adherence at the beginning, diminishing biofilms formation, and increasing membrane permeability all the time. In vivo, HNK improved C57BL/6 mice outcome by reducing disease severity (clinical scores), neutrophil infiltration (MPO, FCM, and IFS), and fungal loading (plate count). RT-PCR, Western blot, and ELISA revealed that HNK downregulated mRNA and protein expression levels of Toll-like receptor-2 (TLR-2), high mobility group box 1 (HMGB1), IL-1β, and TNF-α.

Conclusions

Our study suggested HNK played antifungal and anti-inflammatory roles on keratomycosis by reducing survival of fungi, infiltration of leucocytes, and expression of HMGB1, TLR-2, and proinflammatory cytokines, providing a potential treatment for FK.

Association between age-related factors and extubation failure in elderly patients

BACKGROUND

Elderly patients are being increasingly admitted to the intensive care unit (ICU) for mechanical ventilation. Previous studies demonstrated that 20% to 35% of elderly patients were reintubated within 48 to 72 hours after extubation. Given the age-related physiologic changes and multiple comorbidities in elderly patients, the current conventional parameters for predicting extubation outcomes may not be applicable to this population. This study was performed to identify the association between age-related parameters and extubation failure in elderly patients.

METHODS

Intubated elderly patients (age of ≥60 years) admitted to the medical ICU of a university-based hospital from October 2014 to July 2015 were included. Failed extubation was defined as reintubation within 48 hours after the first extubation. The associations of extubation failure with demographic data, vital signs, cognition and anxiety, and ventilator parameters at the time of intubation and extubation were analyzed.

RESULTS

In total, 127 intubated elderly patients were recruited. Extubation failure occurred in 15 patients (11.8%). Patients with failed extubation had a lower body temperature (37.0°C vs. 37.3°C, P < 0.05) but a higher Facial Anxiety Scale (FAS) score than those with successful extubation (3 vs. 2, P < 0.05). Patients with extubation failure had significantly higher levels of blood urea nitrogen (BUN) (39.88 vs. 58.47 g/dL), serum sodium (137.66 vs. 141.47 mmol/L), and serum calcium (9.52 vs. 10.0 g/dL) but a wider anion gap (12.23 vs. 9.97), but no significant differences in respiratory parameters were found between the two groups. Multiple logistic regression revealed no independent factors associated with successful extubation.

CONCLUSION

This study revealed no strong predictive factors. However, several physiological parameters (lower body temperature and higher FAS scores) and metabolic parameters (BUN, sodium, calcium, and anion gap) were significantly associated with the rate of extubation failure.

Biological markers for anxiety disorders, OCD and PTSD: A consensus statement. Part II: Neurochemistry, neurophysiology and neurocognition

OBJECTIVE

Biomarkers are defined as anatomical, biochemical or physiological traits that are specific to certain disorders or syndromes. The objective of this paper is to summarise the current knowledge of biomarkers for anxiety disorders, obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD).

METHODS

Findings in biomarker research were reviewed by a task force of international experts in the field, consisting of members of the World Federation of Societies for Biological Psychiatry Task Force on Biological Markers and of the European College of Neuropsychopharmacology Anxiety Disorders Research Network.

RESULTS

The present article (Part II) summarises findings on potential biomarkers in neurochemistry (neurotransmitters such as serotonin, norepinephrine, dopamine or GABA, neuropeptides such as cholecystokinin, neurokinins, atrial natriuretic peptide, or oxytocin, the HPA axis, neurotrophic factors such as NGF and BDNF, immunology and CO2 hypersensitivity), neurophysiology (EEG, heart rate variability) and neurocognition. The accompanying paper (Part I) focuses on neuroimaging and genetics.

CONCLUSIONS

Although at present, none of the putative biomarkers is sufficient and specific as a diagnostic tool, an abundance of high quality research has accumulated that should improve our understanding of the neurobiological causes of anxiety disorders, OCD and PTSD.

Targeted Metabolomic Pathway Analysis and Validation Revealed Glutamatergic Disorder in the Prefrontal Cortex among the Chronic Social Defeat Stress Mice Model of Depression

Major depressive disorder (MDD) is a severe psychiatric disease that has critically affected life quality for millions of people. Chronic stress is gradually recognized as a primary pathogenesis risk factor of MDD. Despite the remarkable progress in mechanism research, the pathogenesis mechanism of MDD is still not well understood. Therefore, we conducted a liquid chromatography-tandem mass spectrometry (LC-MS/MS) detection of 25 major metabolites of tryptophanic, GABAergic, and catecholaminergic pathways in the prefontal cortex (PFC) of mice in chronic social defeat stress (CSDS). The depressed mice exhibit significant reduction of glutamate in the GABAergic pathway and an increase of L-DOPA and vanillylmandelic acid in catecholaminergic pathways. The data of real-time-quantitative polymerase chain reaction (RT-qPCR) and Western blotting analysis revealed an altered level of glutamatergic circuitry. The metabolomic and molecular data reveal that the glutamatergic disorder in mice shed lights to reveal a mechanism on depression-like and stress resilient phenotype.

Depression and anxiety predict sex-specific cortisol responses to interpersonal stress

Clinical theories posit interpersonal stress as an important factor in the emergence and exacerbation of depression and anxiety, while neuroendocrine research confirms the association of these syndromes with dysregulation in a major stress response system, the hypothalamic-pituitary-adrenal (HPA) axis. However, the proposal that depression and anxiety symptoms and diagnoses are associated with problematic HPA responses to close relationship stress has not been directly tested. We examined 196 heterosexual dating couples' depression and anxiety symptoms and diagnoses, assessed with questionnaires and diagnostic interviews, in relation to cortisol responses to discussion of an unresolved relationship conflict. Participants provided seven salivary samples in anticipation of and directly following the discussion, and throughout an hour-long recovery period, which were assayed for cortisol. Multilevel models of the HPA response predicted by symptoms or diagnoses showed that women's depressive symptoms predicted attenuated cortisol levels, with a flatter response curve. In contrast, men's depression symptoms and women's anxiety symptoms and diagnoses predicted higher cortisol levels. These findings highlight the importance of examining sex differences in responses to interpersonal stressors for understanding HPA dysregulation in internalizing psychopathology.

The nosologic relationship between generalized anxiety disorder and major depression

Generalized anxiety disorder (GAD) has undergone a series of revisions in its diagnostic criteria that has moved it, nosologically, away from its original affiliation with panic disorder (PD) and closer to major depressive disorder (MDD). This, together with its high comorbidity and putative shared genetic risk with MDD, has brought into question its place in future psychiatric nosology, prompting the planners of Diagnostic and Statistical Manual-V (DSM-V) and International Classification of Diseases-11 (ICD-11) to set up a workgroup tasked to better understand the relationship between GAD and MDD. This review attempts to summarize the extant data to compare GAD and MDD on a series of research validators to explore this relationship. Although insufficient data currently exist for GAD in several key validator classes, tentative conclusions can be drawn on the diagnostic status of GAD in relation to MDD. Although GAD possesses substantial overlap with MDD in the areas of genetics, childhood environment, demographics, and personality traits, this tends to hold true for other anxiety disorders (ADs) as well, with the strongest evidence for PD. Data from life events, personality disorders, biology, comorbidity, and pharmacology are mixed, showing some areas of similarity between GAD and MDD but some clear differences, again with a moderate degree of nonspecificity. Thus, although the bulk of evidence supports a close underlying relationship between them, the relatively nonspecific nature of these findings provides little more reason to question the nosologic validity of GAD in relation to MDD than that of some other anxiety disorders.

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.

Platelets: A possible glance into brain biological processes in schizophrenia

Schizophrenia is a severe mental disorder, characterized by behavioral, emotional and cognitive disturbances, which commonly follows a chronic course. Diagnostic accuracy, management plans, treatment evaluation and prognosis are dependent on relatively subjective assessments. Despite extensive research and improvement in imaging technology, as well as modern genetic and molecular methodologies, the biological basis of this disease is still unclear. Therefore, there is a need for objective and valid biological markers. Platelets have often been used as a model in neurobiological research. The accessibility of platelets and their similarities with neurons turns them into an attractive candidate to search for biological markers for diagnosis and for unraveling pathophysiological processes relevant to the etiology of brain disorders, including schizophrenia. The present review addresses the main changes in platelet physiology observed in schizophrenia and its response to antipsychotic medication. We summarize numerous studies demonstrating impaired metabolism, uptake and receptor kinetics of schizophrenia-relevant neurotransmitters, abnormalities in membrane derived phospholipids and polyunsaturated fatty acids, as well as dysfunctions in the mitochondria. These changes fit with the various hypotheses raised for the etiology of schizophrenia, including the dopamine-glutamate hypothesis, the autoimmune hypothesis, the polyunsaturated fatty acid hypothesis and the impaired energy metabolism hypothesis. Despite extensive research in platelets, no conclusive reliable biomarker has been identified yet. This review suggests that the clinical heterogeneity and the biological complexity of schizophrenia lead to the inevitable conclusion that biomarkers will be identified only for subgroups characterized according to the different diagnostic criteria. Moreover, any biomarker would have to be an array of interrelated factors or even a set of several such arrays.

Gender effect on the relationship between stress hormones and panic-agoraphobic spectrum dimensions in healthy subjects

INTRODUCTION

Alterations of the hypothalamic-pituitary-adrenal (HPA) axis and of its peripheral indices have been reported in both normal and pathological anxiety with controversial findings. The aim of the present study was to investigate the possible correlations between serum cortisol and dehydroepiandrosterone-sulfate (DHEA-S) levels and DHEA-S/cortisol ratio, and panic-agoraphobic spectrum dimensions in a sample of healthy subjects.

METHODS

Forty-two healthy subjects of both sexes, with no current or lifetime psychiatric disorders, were assessed by means of the Structured Clinical Interview for DSM-IV (SCID-I/P) and the so-called Panic Agoraphobic Spectrum-Self Report lifetime version (PAS-SR).

RESULTS

Significant, negative correlations were found between cortisol levels and the total score of the separation sensitivity, panic-like symptoms, and medication/substance sensitivity PAS-SR domains. The PAS-SR total and the panic-like symptoms domain scores were positively related to the DHEAS/cortisol ratio. When the sample was divided in women and men, these correlations were present in women only.

DISCUSSION

These findings, while indicating the presence of significant relationships between panic-agoraphobic traits and some indices of HPA axis functioning in healthy women, would suggest this as one of the factors explaining the greater vulnerability of women to cross the line between normal and pathological anxiety.

CONCLUSIONS

Further studies are needed to explore gender differences in the relationships between HPA axis alterations and the panic-agoraphobic spectrum dimensions.

Decreased response to social defeat stress in μ-opioid-receptor knockout mice

Substantial evidence exists that opioid systems are involved in stress response and that changes in opioid systems in response to stressors affect both reward and analgesia. Reportedly, mice suffering chronic social defeat stress subsequently show aversion to social contact with unfamiliar mice. To further examine the role of opioid systems in stress response, the behavioral and neurochemical effects of chronic social defeat stress (psychosocial stress) were evaluated in μ-opioid-receptor knockout (MOR-KO) mice. Aversion to social contact was induced by chronic social defeat stress in wild-type mice but was reduced in MOR-KO mice. Moreover, basal expression of brain-derived neurotrophic factor (BDNF) mRNA in MOR-KO mice hippocampi was significantly lower than in wild-type mice. Psychosocial stress significantly decreased BDNF mRNA expression in wild-type mice but did not affect BDNF expression in MOR-KO mice; no difference in basal levels of plasma corticosterone was observed. These results suggest that the μ-opioid receptor is involved in the behavioral sequelae of psychosocial stress and consequent regulation of BDNF expression in the hippocampus, and may play an important role in psychiatric disorders for which stress is an important predisposing or precipitating factor, such as depression, posttraumatic stress disorder, and social anxiety disorder.

Sex differences in salivary cortisol in response to acute stressors among healthy participants, in recreational or pathological gamblers, and in those with posttraumatic stress disorder

Sex differences in incidence and severity of some stress-related, neuropsychiatric disorders are often reported to favor men, suggesting that women may be more vulnerable to aberrant hypothalamic-pituitary-adrenal (HPA) axis responses to stress. In this review, we discuss several investigations that we, and others, have conducted assessing salivary cortisol as a measure of HPA function. We have examined basal cortisol among healthy men and women and also following acute exposure to stressors. Among healthy participants, men had higher basal cortisol levels than did women. In response to acute stressors, such as carbon dioxide or noise, respectively, cortisol levels were comparable between men and women or higher among women. We have also examined cortisol levels among those with problem eating, gambling, or posttraumatic stress disorder (PTSD). Women with restrained eating habits have higher basal cortisol levels than do women without restrained eating habits. Pathological gamblers have more aberrant stress response to gambling stimuli than do recreational gamblers, and these effects are more prominent among men than women. Men who have motor vehicle accident related PTSD, demonstrate more aberrant cortisol function, than do their female counterparts. Although these sex differences in cortisol seem to vary with type of stress exposure and/or pathophysiological status of the individual, other hormones may influence cortisol response. To address this, cortisol levels among boys and girls with different stress-related experiences, will be the subject of future investigation.

Anti-depressant and anxiolytic like behaviors in PKCI/HINT1 knockout mice associated with elevated plasma corticosterone level

BACKGROUND

Protein kinase C interacting protein (PKCI/HINT1) is a small protein belonging to the histidine triad (HIT) family proteins. Its brain immunoreactivity is located in neurons and neuronal processes. PKCI/HINT1 gene knockout (KO) mice display hyper-locomotion in response to D-amphetamine which is considered a positive symptom of schizophrenia in animal models. Postmortem studies identified PKCI/HINT1 as a candidate molecule for schizophrenia and bipolar disorder. We investigated the hypothesis that the PKCI/HINT1 gene may play an important role in regulating mood function in the CNS. We submitted PKCI/HINT1 KO mice and their wild type (WT) littermates to behavioral tests used to study anti-depressant, anxiety like behaviors, and goal-oriented behavior. Additionally, as many mood disorders coincide with modifications of hypothalamic-pituitary-adrenal (HPA) axis function, we assessed the HPA activity through measurement of plasma corticosterone levels.

RESULTS

Compared to the WT controls, KO mice exhibited less immobility in the forced swim (FST) and the tail suspension (TST) tests. Activity in the TST tended to be attenuated by acute treatment with valproate at 300 mg/kg in KO mice. The PKCI/HINT1 KO mice presented less thigmotaxis in the Morris water maze and spent progressively more time in the lit compartment in the light/dark test. In a place navigation task, KO mice exhibited enhanced acquisition and retention. Furthermore, the afternoon basal plasma corticosterone level in PKCI/HINT1 KO mice was significantly higher than in the WT.

CONCLUSION

PKCI/HINT1 KO mice displayed a phenotype of behavioral and endocrine features which indicate changes of mood function, including anxiolytic-like and anti-depressant like behaviors, in conjunction with an elevated corticosterone level in plasma. These results suggest that the PKCI/HINT 1 gene could be important for the mood regulation function in the CNS.

Higher plasma ACTH levels in adults with Asperger syndrome

OBJECTIVE

The aim of this preliminary study was to characterize the levels of plasma adrenocorticotropic hormone (ACTH) and cortisol in adult patients with Asperger syndrome (AS).

METHODS

Twenty medication-free individuals with high-functioning AS were recruited from a clinic specialized in autism spectrum disorders. Ten age-matched healthy persons (hospital staff or students) with no neuropsychiatric disorders served as controls. Blood samples for the assessment were collected at 8:00 a.m.

RESULTS

The patients with AS had significantly higher plasma-ACTH values than did the healthy controls. Plasma-cortisol levels were similar in both groups.

CONCLUSION

Increased plasma-ACTH levels are associated with AS. Future studies are needed to clarify whether this finding is a biological consequence of chronic anxiety and elevated stress, or a sign of facilitated response to an acute novel stressor.

Cortisol response to diazepam: its relationship to age, dose, duration of treatment, and presence of generalized anxiety disorder

OBJECTIVE

Acute diazepam administration has been shown to decrease plasma cortisol levels consistent with decreased activity of the hypothalamic-pituitary-adrenal axis, especially in individuals experiencing stress. However, the effects of chronic diazepam treatment on cortisol have been less studied, and the relationship to age, anxiety, duration of treatment, and dose are not well understood.

METHOD

This double-blind placebo-controlled study examined acute and chronic effects of diazepam on plasma cortisol levels in young (19-35 years) and elderly (60-79 years) individuals with and without generalized anxiety disorder (GAD). Subjects received single oral challenges of placebo or diazepam (2.5 mg or 10 mg) in a placebo-controlled cross-over design, followed by 3 weeks of chronic daily treatment with 2.5 mg or 10 mg diazepam or placebo taken at 10 p.m., and then by a final acute challenge with a single oral dose of the same study medication received during chronic treatment.

RESULTS

The elderly experienced significant reductions in plasma cortisol levels compared to placebo both in the initial challenge and during chronic treatment, but the young did not. However, cortisol response to drug was comparable in both groups. Final challenge did not produce any significant cortisol effects in either group and the cortisol response in the elderly was significantly reduced compared to the initial challenge. GAD status was not a factor in plasma cortisol responses to diazepam.

CONCLUSIONS

Diazepam reduced cortisol both acutely and during chronic treatment, but not during final challenge, consistent with some tolerance development. This effect was most apparent in the elderly compared with the young adults and was not modulated by GAD status or dosage, and was not related to drug effects on performance and on self-ratings of sedation and tension.

Anxious and depressive disorders and their comorbidity: effect on central nervous system noradrenergic function

BACKGROUND

Although comorbidity of anxiety with depression is common, investigations of physiologic abnormalities related specifically to comorbidity are rare. This study examined relationships of DSM-IV-defined depression, anxiety, and their comorbidity to noradrenergic function measured by blunting of the growth hormone (GH) response to the alpha2 adrenoreceptor agonist (and imidazoline receptor agent) clonidine and by blood pressure and symptom responses.

METHODS

Fifteen subjects with pure social anxiety or panic disorder, 15 with pure major depression, and 18 with both depression and anxiety were compared with healthy control subjects matched for age and gender. Other factors known to affect GH (weight, menstrual status, prior antidepressant, or other drug exposure) were controlled.

RESULTS

Anxiety produced GH blunting, but depression was associated with normal GH responses. The comorbid state did not affect results beyond the impact of anxiety. Preclonidine stress-related GH elevations were observed, to the greatest degree in anxious subjects. Relevant symptom, but not blood pressure, changes were significantly associated with blunting.

CONCLUSIONS

With use of pure depression and anxiety groups and careful control of other factors known to affect GH, these results demonstrate central nervous system noradrenergic dysfunction in anxiety disorders. In contrast to less rigorously controlled studies, noradrenergic function in depression was normal.

Increased sympathetic response to standing in panic disorder

Although autonomic function has been investigated in panic disorder (PD), previous studies have not used non-invasive beat by beat blood pressure (BP) monitoring to assess the rapid dynamics of BP during autonomic reflex tests. The hypothesis of the current study was that patients with PD would show increased cardiovascular sympathetic reactivity compared with healthy or anxious controls, as assessed by the initial overshoot of diastolic BP during the immediate response to standing. Patients with PD (n=56), social phobia (n=28) and healthy volunteers (n=56) were tested using finger photoplethysmography during an orthostatic challenge. Panic disorder patients showed an increased BP overshoot compared with both control groups. Moreover, in a preliminary assessment of selective serotonin reuptake inhibitor treatment effects, the BP overshoot was significantly reduced towards normal values. These findings are consistent with recent evidence for increased sympathetic baroreflex function in PD and may be relevant to the pathophysiology of the disorder.

Trait anxiety and tamoxifen effects on bone mineral density and sex hormone- binding globulin

OBJECTIVE

Tamoxifen therapy preserves BMD of the lumbar spine and increases levels of SHBG. We assessed whether trait anxiety, a factor linked with a reactive endocrine system, is associated with differential changes in BMD and SHBG levels in response to tamoxifen therapy.

METHODS

Postmenopausal women (N= 140) with axillary-node-negative breast cancer participated in a 2-year randomized, double-blind, placebo-controlled trial of tamoxifen (10 mg twice a day). Levels of BMD and SHBG were assessed at baseline and at 3, 6, 12, 18, and 24 months.

RESULTS

Trait anxiety predicted tamoxifen-induced changes in lumbar spine BMD; high levels of trait anxiety were associated with significantly greater lumbar spine BMD at 3, 12, and 24 months (p values <.05) for women on tamoxifen therapy. High anxiety also was associated with lower levels of SHBG for women using tamoxifen at 3, 12, 18, and 24 months (p values <.05).

CONCLUSIONS

Trait anxiety is associated with greater preservation of lumbar spine BMD in response to tamoxifen and with a suppression of tamoxifen-induced increases in SHBG. Trait anxiety and other affective traits may serve as indicators of underlying physiological processes that moderate the effects of estrogen receptor modulators (such as tamoxifen) in clinical trials. Such data may help to elucidate the physiological mechanisms responsible for some of the variation in individual responses to treatment.

Decreased reuptake of serotonin in human platelets after surgery

We have documented earlier a decrease in platelet serotonin and a concurrent increase in plasma serotonin, 5-hydroxytryptamin (5-HT) after various forms of stress, suggesting a disturbed platelet 5-HT reuptake mechanism following stress. In order to further elucidate these findings, we have studied platelet 5-HT reuptake kinetics (Vmax and Km) in nine patients before and 4 days after major, uncomplicated abdominal surgery. We found a significant decrease in the maximal 5-HT reuptake velocity (Vmax) after surgery and changes in Km, verifying alterations in the affinity of the platelet 5-HT transport system. The present results thus confirm the hypothesis that 5-HT reuptake kinetics are altered following adrenergic hyperactivity. A decrease in platelet 5-HT reuptake may bear implications for our understanding of poststress adaptive changes in the cardiovascular system as well as in the central nervous system (CNS) serotonergic neurones following stressful stimulation.

Salivary cortisol levels in socially phobic adolescent girls

Anxiety disorders such as social phobia (SP) often have their onset during adolescence and frequently precede the onset of major depression. Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is well-documented in major depression. Consequently, there is considerable interest in HPA function in anxiety disorders. We examined salivary cortisol levels in 27 SP adolescent girls and 21 matched controls during normal daily activities, and immediately before and after a modified Trier Social Stress Test (TSST). Both SP subjects and controls showed significant elevations in cortisol levels prior to the TSST, and prior to attending school. These results suggest that salivary cortisol is a sensitive measure of anticipatory anxiety, but we failed to find significant differences between SP subjects and controls.

Trait-like immunological and hematological measures in female rhesus across varied environmental conditions

In this 2-year longitudinal study, 45 2-year-old female rhesus were observed as they were captured and removed from a free-ranging setting (Phase I), single caged for 1 year (Phase II), and housed in small, stable social groups for an additional year (Phase III). During the study, eight blood samples were taken, and hematological, immunological, and hormonal variables were assayed to determine whether 1) any of the measures would exhibit trait-like, inter-individual longitudinal stability, despite fluctuations in population means induced by Phases I, II, and III; 2) plasma concentrations of cortisol, prolactin, and norepinephrine would be lowest in Phase III, and elevated during the periods of acute and chronic stress associated with Phases I and II; and 3) there would be any evidence of immunosuppression associated with Phases I and II. The results suggest that the majority of hematological/immunological variables were trait-like throughout the study in contrast to plasma cortisol, prolactin, and norepinephrine concentrations. Thus, red blood cells, hemoglobin, hematocrit, platelets, mean corpuscular volume and hemoglobin, as well as white blood cells, the absolute number of CD4+ (T-helper/inducer) cells, the absolute number of CD8+ (T-suppressor/cytotoxic) cells, total T cells (CD2+%), total B cells (CD20+%), and the ratio of CD4+/CD8+ cells were trait-like. The hematological measures were changed dramatically by capture and the subsequent single caging, with most not recovering to presumed baselines until after 12-28 weeks. The immune measures were depressed at capture (excepting B cells), and during 7 months of single caging failed to return to normal levels associated with social housing. We thus conclude that single housing can produce significant, long-term features of immunosuppression. Capture produced significant increases in plasma cortisol, prolactin, and norepinephrine concentrations. Long periods of single caging produced significant increases in plasma prolactin concentrations, indicative of stress-induced anxiety, and may also have been associated with down-regulation of plasma norepinephrine and cortisol concentrations.

Cytokines in de obsessief compulsieve stoornis en in anorexia nervosa: een overzicht

The alterations in the inflammatory response system (IRS) appear to be quite different between OCD and anorexia nervosa and are also different from the changes observed in major depression. In anorexia nervosa, there is some evidence for increased production of monocytic cytokines, i.e. tumor necrosis factor-α (TNFα) and interleukin-6 (IL-6), and decreased production of Th-1 like cytokines, i.e. IL-2 and IFNγ. In the same patients there are also signs of immunosuppression, e.g. lowered numbers of CD4 and CD8 T cells and increased production of transforming growth factor-beta (TGFβ). The increased production of monocytic cytokines may be the consequence of the hyponutritional status of those patients. The diminished production of the Th-1 like cytokines may be the consequence of at least four different factors: 1) the deficiency in nutritional factors; 2) neuroendocrine disorders, such as increased Cortisol production; 3) the increased TGFβ production; and 4) lower serum dipeptidyl peptidase activity. In OCD no consistent or specific alterations in the IRS are observed. There is no evidence that IRS activation may play a role in the pathophysiology of OCD and anorexia nervosa.

Hyper-reactive hypothalamo-pituitary-adrenocortical axis in rats bred for high anxiety-related behaviour

Psychiatric patients suffering from anxiety disorders or endogenous depression exhibit increased activity in their hypothalamo-pituitary-adrenocortical (HPA) axis. Recently, two Wistar rat lines, bred for high (HAB) and low (LAB) anxiety-related behaviour on the elevated plus-maze, were described as a unique psychopathological animal model (1). The present study focused on the HPA axis reactivity of HAB and LAB animals to an emotional stressor. Thus, adult male HAB and LAB animals, fitted with jugular vein catheters 5 days prior to the experiment, were exposed to an open arm of the elevated plus-maze for 5 min. Whereas basal levels of ACTH and corticosterone were similar in both lines, HAB rats showed higher plasma concentrations at 5 and 15 min following stressor exposure (both hormones and both time points: P<0.01 vs LAB). Furthermore, increased basal (P<0.05 vs LAB) and stimulated (P<0.01 vs LAB) prolactin concentrations in HAB rats were found. In contrast to ACTH, corticosterone and prolactin, plasma oxytocin and vasopressin levels did not differ between HAB and LAB animals; oxytocin, but not vasopressin, responding to open arm exposure with a significant increase in both lines (P<0.05). In conclusion, particularly due to the association between inborn anxiety and HPA axis hyper-reactivity, the HAB rat represents a promising animal model for further investigation of the relationship between emotional disturbance and neuroendocrine activity.

Anxiety and cardiovascular reactivity in the Tecumseh population

OBJECTIVE

Increased cardiovascular reactivity has been proposed to be a critical mediator in the development of hypertension and cardiovascular disease. The personality factors associated with cardiovascular reactivity are still subject to debate. The studies reported here were undertaken to examine the relationship between trait anxiety and cardiovascular stress reactivity in a community-based sample (Tecumseh).

DESIGN AND METHODS

All studies were carried out in an outpatient setting. Cardiovascular reactivity to isometric handgrip and mental arithmetic was assessed and recorded by automatic blood pressure monitoring in 832 subjects aged 19-41 years. Spielberger trait and state anxiety measures were collected immediately before the stressors were applied.

RESULTS

No differences in baseline heart rate, systolic or diastolic blood pressure were observed across anxiety categories. There was a clear negative correlation between trait anxiety and cardiovascular reactivity to mental arithmetic. The pattern was less clear in response to isometric handgrip.

CONCLUSIONS

These results suggest that individuals with high trait anxiety demonstrate reduced cardiovascular reactivity while those with low trait anxiety demonstrate increased reactivity, whereas the opposite might have been expected.

Plasma interleukin-1 beta and tumor necrosis factor concentrations in obsessive-compulsive disorders

Plasma interleukin-1 beta (Il-1 beta) and tumor necrosis factor-alpha (TNF-alpha) concentrations were measured twice, at a 48-hour interval, in 27 drug-free obsessive-compulsive patients (12 women and 15 men) and in 27 sex-age-matched healthy controls. Il-1 beta and TNF-alpha concentrations were significantly lower in patients than in controls, whereas there were no differences in either group between men and women, between the samples of the two days, or, in the patients, between those who had and those who had not been previously treated with psychopharmacologic drugs.

Lesion of the habenular efferent pathway produces anxiety and locomotor hyperactivity in rats: a comparison of the effects of neonatal and adult lesions

Recent studies have implicated the habenula in modulating states of arousal and chronic responses to stress. We examined whether lesion of the habenula efferent pathway, the fasciculus retroflexus (FR), at either 3 (P3) or 70 (P70) days of age affects stress-related anxiety (elevated plus-maze test) and activity levels (open-field test) in rats tested as adults. Both P3- and P70-lesioned rats showed chronically elevated plasma levels of corticosterone. Rats receiving FR lesions as neonates (P3) exhibited greater open arm avoidance on the elevated plus-maze than controls 2 months postoperatively, suggesting a heightened state of anxiety. In contrast, P70-lesioned rats behaved similarly to controls on the plus-maze, but showed increased locomotion and increased grooming in the open field, effects not observed in P3-lesioned rats. When an additional stressful condition was imposed (5 days of social isolation plus 24 h food deprivation) before testing, both FR-lesion groups showed an attenuation of the normal behavioral responses (decreased open-arm entries/time in open arms, increased freezing). The effects of FR lesions on activity and behavioral indices of anxiety may be due to disruption of lateral habenular projections to dopaminergic neurons in the ventral tegmentum and/or projections to regions containing high concentrations of benzodiazepine receptors, the median and dorsal raphe and dorsal periaqueductal gray. Behavioral differences observed as a function of lesion age suggest differential capabilities of P3- and P70-lesioned rats to utilize compensatory mechanisms to correct FR lesion-induced deficits.

Platelet alpha 2-adrenoreceptors, catecholamines, hemodynamic variables, and anxiety in panic patients and their asymptomatic relatives

The objectives of this study were to a) replicate our prior finding of a decreased number (Bmax) of platelet alpha 2-adrenoreceptors in panic disorder, b) determine if binding is also decreased in asymptomatic first-degree relatives of panic patients (known to be at increased risk for developing panic), and c) evaluate the effect of treatment on the presumptive decrease in binding (i.e., is the decrease a state or a trait marker for panic?). Panic patients had clonidine and yohimbine platelet-binding assays, symptom ratings, and measurement of lying and standing plasma epinephrine, norepinephrine, systolic and diastolic blood pressure, and heart rate before treatment, after approximately 2 months of medication (fluoxetine, tricyclics, or alprazolam) and/or cognitive behavioral treatment, and after symptom remission while drug free; normal subjects had determinations of the same measures at approximately the same time intervals. Relatives of both groups had one determination only of all measures. Tritiated clonidine binding was decreased and lying heart rate was increased in patients before treatment. Magnitude of binding decrease was correlated with symptom severity and standing norepinephrine. No binding abnormality was seen in first-degree relatives of patients. Treatment increased clonidine binding in patients. Both patients and relatives of patients showed significantly increased standing plasma norepinephrine in comparison to controls. There is a state-related decrease in binding, associated with symptom severity and norepinephrine, in panic disorder. Abnormal reactivity of norepinephrine to standing might be a marker for increased likelihood of panic development in individuals at risk.

Noradrenergic mechanisms in stress and anxiety: II. Clinical studies

Studies in animals have shown a relationship between alterations in noradrenergic brain system function and behaviors of anxiety and fear. These findings have generated the hypothesis that the symptoms seen in patients with anxiety disorders may be related to alterations in noradrenergic function. A number of clinical studies have tested this hypothesis, utilizing measures of catecholaminergic function such as heart rate and blood pressure, measurement of norepinephrine and its metabolites in urine and plasma and adrenergic receptor binding in platelets, as well as pharmacological challenge to the noradrenergic system. Acute stressors, such as public speaking, have been associated with an increase in heart rate, blood pressure, and norepinephrine and its metabolites in urine and plasma. Findings in patients with panic disorder at baseline related to heart rate, blood pressure, baseline norepinephrine and its metabolites, and platelet adrenergic receptors have been mixed, while the most consistent findings have been blunted growth hormone response to clonidine and increased 3-methoxy-4-hydroxy-phenylethylene-glucol (MHPG) and anxiety following stimulation of the noradrenergic system with yohimbine. Baseline measures of noradrenergic function in patients with posttraumatic stress disorder (PTSD) have also been mixed, while an increased heart, blood pressure and norepinephrine response to traumatic reminders, as well as increased behavioral (as well as different brain metabolic) response to yohimbine, have been found in PTSD. There are fewer studies of noradrenergic function in the other anxiety disorders, and the findings there have not been consistent. These studies provide evidence for increased noradrenergic responsiveness in panic disorder and PTSD, although there does not appear to be an alteration in baseline noradrenergic function in these patients.

Plasma interleukin-1 beta concentrations in panic disorder

Plasma interleukin-1 beta (IL-1 beta) concentrations were measured in 10 outpatients with panic disorder before and on days 30 and 32 of treatment with alprazolam (2-2.5 mg/day). IL-1 beta concentrations were found to be significantly higher in patients than in control subjects both before and during therapy. Thus, IL-1 beta levels may be a marker of panic disorder that is not related to the current level of symptomatology.

Subjective anxiety measurements and cortisol responses in adults who stutter

Anxiety, as measured by self-report inventories and salivary cortisol levels, was examined in 11 males who stutter and 11 males who do not stutter during baseline, low stress, and high stress sessions. During the high stress session salivary cortisol was significantly greater in persons who stutter than in persons who do not stutter. No significant differences were found between the two groups on the State-Anxiety Inventory, Trait-Anxiety Inventory, or the Personal Report of Communication Apprehension. Significant differences in anxiety levels among the baseline, low stress, and high stress sessions for both groups of subjects were found for the State-Anxiety Inventory. No other significant differences or relationships were found between the two groups.

Normal urinary free cortisol and postdexamethasone cortisol in social phobia: comparison to normal volunteers

In primates, social stress is associated with activation of the hypothalamic-pituitary-adrenal (HPA) axis. Social phobia is a common, often disabling, form of pathological anxiety characterized by marked distress in situations involving possible scrutiny or evaluation. Little is known about HPA function in patients with social phobia. We examined 24-hour excretion of urinary free cortisol (UFC) in 54 patients with social phobia and post-dexamethasone cortisol levels in 64 patients with social phobia and found no evidence of HPA-axis overactivity compared to normal controls, despite pathological levels of anxiety.

Anxiolytic-like effect of neuropeptide Y (NPY), but not other peptides in an operant conflict test

The peptide messengers neuropeptide Y (NPY), growth hormone-releasing hormone (GHRH), atrial natriuretic peptide (ANP) and beta-endorphin (BEND) were tested in an animal model of anxiety, the Geller-Seifter conflict test. Rats were subjected to a multiple schedule consisting of three components: in the first component, lever-pressing produced food-reward ('unpunished responding'). The second component was a time-out period, during which lever-pressing had no consequences. During the third component, lever-pressing produced food-reward, but was also punished by an incremental foot-shock ('punished responding'). After establishing a stable baseline of both unpunished and punished responding, animals were injected with various doses of NPY, GHRH, ANP, BEND, or with saline into the lateral cerebral ventricle, and testing was repeated. While changes in unpunished responding can reflect alterations in performance factors or motivational strength, increases in punished responding have previously been shown to be highly specific for anxiety-reducing drugs, such as the benzodiazepines. NPY markedly and dose-dependently increased punished responding. A smaller increase of unpunished responding was also seen. These results add further support to the hypothesis that NPY may be an endogenous anxiolytic. GHRH, ANP and END did not affect punished responding.

Continuous physiological changes and subjective reports in panic patients: a preliminary methodological report

Six panic disorder patients and six matched control subjects were studied using a new technique allowing continuous and simultaneous monitoring of physiological responses (blood pressure, heart rate, respiration) and subjective reports of anxiety and panic. This was done before, during, and after CO2 inhalation. Panic patients had significantly higher variability in their heart rate, blood pressure, and breathing rate than the control subjects. They also had irregular breathing patterns with frequent pauses. We identified three different patterns of response to CO2 inhalation in the panic patients. Some patients who panicked on CO2 showed a definite association between changes in physiological responses that preceded their subjective ratings of anxiety; however, others did not show this pattern. The possibility of different physiological mechanisms of panic in different patients is discussed.

Psychophysiological response patterns to positive and negative film stimuli

The aim of the present study was to investigate differential emotional response patterns to film stimuli by multimodal assessment of mood ratings, perception of bodily sensations, salivary cortisol, autonomic variables and facial electromyogram (EMG). Film stimuli, chosen to elicit positive and negative emotional states, were presented to 12 subjects with general anxiety disorder and 12 controls. Changes in mood, bodily sensations, autonomic activity (heart rate, respiration rate and skin conductance), facial EMG activity (corrugator and zygomatic muscle region) and salivary cortisol were measured. Analyses revealed differential changes in all response systems except for respiration rate and salivary cortisol. Although high-anxious subjects did not differ from controls in their average responses to the negative film stimuli, there is a tendency of a greater coherence of emotional response components in generalized anxiety subjects. However, spontaneous facial expressions to positive and negative film stimuli were associated with augmented electrodermal activity within both groups. Results are interpreted in light of directional response fractionation, dimensional approaches of emotion, and the facial feedback literature.

Melatonin response to bright light in recovered, drug-free, bipolar patients

Melatonin suppression by bright light was investigated in 15 drug-free euthymic bipolar patients and control subjects matched for age and sex with the patients. There were no differences between groups on the extent of melatonin suppression by 500 lux bright light administered between 0200h and 0400h. These results do not support the hypothesis that melatonin suppression by bright light is a reliable trait marker in recovered bipolar patients.

The brain and higher mental function

Critical evaluation of biological theories of psychiatric disorder requires an understanding of current concepts of higher mental function and its related biology. Both the nature of the topic and the rapidity of advances in the field make it difficult to obtain an updated synthesis. Part I of this paper attempts to provide that by reviewing current concepts of the mind/body relationship, emotion, arousal, attention, consciousness and motivation. Part II considers those concepts in relation to recent work on the structure and function of the reticular, limbic and anterior cerebral systems. It is concluded that the model of the limbic system as subserving emotional life could now perhaps be set aside in favour of the model of a core set of chemically identified neurons in the reticular system being necessary but not sufficient to subserve higher mental function whilst also subserving other integrating functions for which no mental terminology is required. The problem of developing an eclectic theory of higher mental function that will embrace these concepts is discussed.

Adrenergic status in anxiety disorders: platelet alpha 2-adrenergic receptor binding, blood pressure, pulse, and plasma catecholamines in panic and generalized anxiety disorder patients and in normal subjects

In order to evaluate adrenergic function in anxiety disorders, platelet alpha 2-adrenergic binding parameters and supine and standing blood pressure, pulse, and venous plasma epinephrine and norepinephrine were determined in patients with panic attacks or generalized anxiety disorder and in normal subjects. The maximum number of binding sites (Bmax) for the partial agonist tritiated clonidine was significantly lower for both patient groups than for normal subjects, and the Bmax for the antagonist tritiated yohimbine was significantly lower for panic patients. There were no other substantive differences across groups. Prior exposure to psychotropic drugs might account for the results for clonidine binding, but not for yohimbine. The Bmax for clonidine was correlated with norepinephrine increases upon standing and, for panic patients, with the severity of full unexpected panic attacks. These data provide further evidence of adrenergic receptor abnormalities in people with anxiety disorders.

Menstrual fluctuation in the symptoms of panic anxiety

Ten women with DSM-III-defined panic attacks (five with and five without agoraphobia) had symptom severity rated daily, weekly, and retrospectively through one full menstrual cycle. Substantial fluctuations in retrospective ratings of severity were observed, with the premenstrual week being rated as most severe. Daily and weekly ratings showed much smaller fluctuations in the predicted direction. Possible reasons for this outcome are considered.