Cortisol and ACTH responses to the Dex/CRH test: influence of temperament

The impact of virtual reality scenes on stress response characteristics of individuals with different personality traits

Virtual reality based physical stress (VRPS) paradigms could eliminate the influence of social factors on participants, and it may be a desirable tool to explore the impact of personality traits on stress levels. In this study, we attempt to explore the effects of VRPS on stress response among individuals with different personality traits. Forty male participants with an average age of 22.79 ± 0.41 years were divided into two groups based on Harm Avoidance (HA) scores of Tridimensional Personality Questionnaire (TPQ), referred to as the Low-HA group and the High-HA group. The stress levels of the participants were assessed using salivary α-amylase (sAA) activity and heart rate variability (HRV) indices pre- and post-stress. The influence of personality traits on stress response among different groups was analyzed. VRPS significantly affected the sAA activity and HRV indicators of both groups. During and after stress, there were significant differences in sAA activity and HRV indicators between the two groups. The sAA levels and HRV indices of the Low-HA group were lower than those of the High-HA group. Furthermore, sAA levels and HRV indices were correlated with the scores of TPQ. VRPS scenarios elicit different stress responses on individuals with different harm avoidance personality traits. Stress evaluation based on VR scenarios presents potential in personality trait assessments, particularly for distinguishing between individuals with low and high HA tendencies.

The relationship between sex, personality traits, and the hypothalamic-pituitary-adrenocortical axis

The aim of our study was to examine whether there are sex-based differences in the relationship between personality traits and hypothalamic-pituitary-adrenal (HPA) axis measures. A total of 106 healthy volunteers (56.6% women; age: 48.0 ± 15.8 years) were studied. The revised temperament and character inventory (TCI-R) and the Childhood Trauma Questionnaire (CTQ) were administered. HPA axis function was assessed using three dynamic measures: the cortisol awakening response (CAR), the diurnal cortisol slope, and the cortisol suppression ratio with 0.25 mg of dexamethasone (DSTR). Female sex was associated with an increased CAR and a more flattened diurnal cortisol slope, although a negative significant interaction between harm avoidance and female sex was found. Regarding the DSTR, perseverance was associated with increased cortisol suppression after dexamethasone; sex did not affect this association. Our study suggests that the relationship between specific personality traits (harm avoidance) and HPA axis measures (CAR, diurnal slope) differs according to sex.

Harm avoidance, daily stress, and problematic smartphone use in children and adolescents

OBJECTIVE

Temperament is close to susceptibility to stress and the increased level of stress may lead problematic smartphone use (PSU). In this study, the relationships between harm avoidance (HA) as a personality trait, daily traits, and PSU in children and adolescents were investigated.

METHODS

At baseline, all participants (184 children and adolescents, mean age 13.15 years) completed questionnaires on PSU using the Smartphone Addiction Scale-Short Version (SAS-SV) and the Korean Smartphone Addiction Proneness Scale (SAPS). The Daily Hassles Questionnaire (DHQ) and Junior Temperament and Character Inventory (JTCI) were also administered to evaluate stress levels and personality traits. SAS-SV, SAPS, and DHQ were reassessed at 3 and 6 months.

RESULTS

Among JTCI temperament, HA displayed robust positive correlations with SAS-SV, SAPS, and DHQ at all time points. Mediation effects of daily stress on the relationship between HA and PSU were observed at baseline, 3, and 6 months.

CONCLUSION

The findings suggest that managing stress may important in PSU children and adolescents with high HA.

Cortisol, Temperament and Serotonin in Karate Combats: An Evolutionary Psychobiological Perspective

Objectives

There is evidence suggesting that in martial arts competitions athletes characterized by higher anxiety and harm avoidance may be more likely to lose a fight. This psychological profile has been hypothesized to explain in part the observation that cortisol is higher in losers before and in response to a competition. An important research target that needs further exploration is the identification of phenotypic traits that can be helpful in predicting athletes’ performance. Here we present a brief description of the theoretical bases that drives our research in the evolutionary psychobiology of sports and illustrate preliminary data on the relationship between the 5HTTLPR genotype, salivary cortisol, temperament and competition.

Methods

Sixty-five healthy male non-professional athletes provided saliva samples 10 min before and after a kumite session and filled out the Tridimensional Personality Questionnaire.

Results

Salivary cortisol levels 10 min before the competition were higher in losers and in athletes with the S allele. Temperament was associated with competition outcome and cortisol: losers were characterized by higher scores of harm avoidance and harm avoidance was positively correlated with cortisol levels.

Conclusions

The results confirm previous findings linking temperamental traits, pre-and post- competition physiological stress response with competition outcome in kumite fight. Moreover, they indicate an association between the 5HTTLPR polymorphism and pre-competition salivary cortisol, thus providing a preliminary but non-conclusive evidence on the role played by the 5HTTLPR genotype as a vulnerability factor in sport competition.

Comparison of hypothalamo-pituitary-adrenal function in treatment resistant unipolar and bipolar depression

Altered functioning of the hypothalamic-pituitary-adrenal (HPA) axis has been demonstrated in patients with treatment-resistant depression, although studies have often conflated patients with unipolar and bipolar depression. This is problematic given that the two groups often present with opposed neurovegetative symptom patterns. The aim of this study was to test, for the first time, whether post-awakening cortisol, a highly reliable, naturalistic measure of HPA functioning, could distinguish patients with clearly defined treatment-resistant unipolar (TRUD) and bipolar depression (TRBD). A total of 37 patients with TRUD, 17 patients with TRBD, and 47 healthy controls were recruited. Areas under the curve (AUC) with respect to the ground (g) and increase (i) of post-awakening cortisol concentrations (awakening, +15, +30, +45, +60, +90 min) were measured over two days. Patients with TRUD had higher total cortisol production in the morning hours compared to controls (AUCg, p = 0.01), while they did not differ in terms of the awakening response (AUCi, p = 0.28). By contrast, subjects with TRBD had lower total cortisol when compared to controls by trend (AUCg, p = 0.07), while they did not differ in the awakening response (AUCi, p = 0.15). A direct comparison of TRUD and TRBD revealed differences in the AUCg (p = 0.003) and AUCi (p = 0.03). This finding of comparatively elevated HPA axis activity in the morning in TRUD and attenuated HPA axis activity in TRBD attests to a fundamental biological distinction between unipolar and bipolar depression. It has implications for the understanding and treatment of bipolar depression and in differentiating the two types of depression.

The link between personality dimensions and pain perception in patients with diabetes mellitus or cancer

BACKGROUND AND AIMS

Diabetes mellitus and cancer are two diseases with a strong psychological impact. Personality traits modulate the perception of pain and the response to disease. The specificity of this study consists of the assessment of personality, pain and emotional impact in the two diseases.

METHOD

The study included 130 participants assigned to 3 groups: patients with diabetes mellitus, patients with cancer disease, and a control group. The personality traits of all the participants were analyzed using Cloninger's Temperament and Character Inventory (TCI). For the evaluation of pain, as well as associated anxiety and depression in the diabetes and cancer groups, the Brief Pain Inventory (BPI) and the Hospital Anxiety and Depression Scale (HADS) were used.

RESULTS

Patients with diabetes mellitus and cancer disease had significantly higher total values on the Harm Avoidance scale (HA) (p<0.001) and lower total values on the Self-Directedness scale (SD), Reward Dependence scale (RD), Cooperativeness scale (CO) (p<0.001) compared to the control group. Major anxiety was predominant in patients with diabetes mellitus (34%), and major depression was prevalent in cancer patients (17.5%). Patients with diabetes mellitus obtained a significantly higher severity score at BPI scale than patients with cancer disease (p=0.03).

CONCLUSIONS

The existence of a mutual personality profile featuring high levels of Harm Avoidance and low levels of Self-Directedness in patients with diabetes mellitus and cancer who experience pain has great implications for the therapeutic approach. A potential future avenue of management in these diseases may lie in targeting particular personality aspects of chronic pain patients.

Inhibited Personality Temperaments Translated Through Enhanced Avoidance and Associative Learning Increase Vulnerability for PTSD

Although many individuals who experience a trauma go on to develop post-traumatic stress disorder (PTSD), the rate of PTSD following trauma is only about 15-24%. There must be some pre-existing conditions that impart increased vulnerability to some individuals and not others. Diathesis models of PTSD theorize that pre-existing vulnerabilities interact with traumatic experiences to produce psychopathology. Recent work has indicated that personality factors such as behavioral inhibition (BI), harm avoidance (HA), and distressed (Type D) personality are vulnerability factors for the development of PTSD and anxiety disorders. These personality temperaments produce enhanced acquisition or maintenance of associations, especially avoidance, which is a criterion symptom of PTSD. In this review, we highlight the evidence for a relationship between these personality types and enhanced avoidance and associative learning, which may increase risk for the development of PTSD. First, we provide the evidence confirming a relationship among BI, HA, distressed (Type D) personality, and PTSD. Second, we present recent findings that BI is associated with enhanced avoidance learning in both humans and animal models. Third, we will review evidence that BI is also associated with enhanced eyeblink conditioning in both humans and animal models. Overall, data from both humans and animals suggest that these personality traits promote enhanced avoidance and associative learning, as well as slowing of extinction in some training protocols, which all support the learning diathesis model. These findings of enhanced learning in vulnerable individuals can be used to develop objective behavioral measures to pre-identify individuals who are more at risk for development of PTSD following traumatic events, allowing for early (possibly preventative) intervention, as well as suggesting possible therapies for PTSD targeted on remediating avoidance or associative learning. Future work should explore the neural substrates of enhanced avoidance and associative learning for behaviorally inhibited individuals in both the animal model and human participants.

Hypothalamic-pituitary-adrenal axis activity in the comorbidity between obsessive-compulsive disorder and major depression

Major depressive disorder (MDD) is the most common psychiatric comorbidity in patients with obsessive-compulsive disorder (OCD). Hypothalamic-pituitary-adrenal (HPA) axis abnormalities have been described in both disorders and might play a role in the association between them. We aimed to study the role of HPA axis activity in the comorbidity between OCD and MDD, while controlling for psychopathological dimensions such as anxiety and depressive symptoms. We studied 324 participants belonging to four diagnostic groups: 1) MDD (n = 101), 2) OCD with comorbid MDD (n = 33), 3) OCD without MDD (n = 52), and 4) healthy subjects (n = 138). State anxiety, trait anxiety and depressive symptoms were assessed. Three HPA axis measures were analyzed in saliva: cortisol awakening response (CAR), diurnal cortisol slope (calculated using two formulas: [1] awakening to 11 p.m. [AWE diurnal slope]; [2] considering fixed time points [FTP diurnal slope] from 10 a.m. to 11 p.m.), and dexamethasone suppression test ratio after 0.25 mg of dexamethasone (DSTR). Multiple linear regression analyses were conducted to explore the contribution of clinical diagnosis and symptom dimensions to each HPA axis measure. A more flattened FTP diurnal cortisol slope was observed for OCD patients with comorbid MDD. Regarding the CAR and DSTR, a significant interaction was found between trait anxiety and OCD, as OCD patients with greater trait anxiety showed an increased CAR and reduced cortisol suppression after dexamethasone administration. Our results suggest that trait anxiety plays an important role in the relationship between HPA axis measures and OCD/MDD comorbidity.

Neural basis of individual differences in the response to mental stress: a magnetoencephalography study

Stress is a risk factor for the onset of mental disorders. Although stress response varies across individuals, the mechanism of individual differences remains unclear. Here, we investigated the neural basis of individual differences in response to mental stress using magnetoencephalography (MEG). Twenty healthy male volunteers completed the Temperament and Character Inventory (TCI). The experiment included two types of tasks: a non-stress-inducing task and a stress-inducing task. During these tasks, participants passively viewed non-stress-inducing images and stress-inducing images, respectively, and MEG was recorded. Before and after each task, MEG and electrocardiography were recorded and subjective ratings were obtained. We grouped participants according to Novelty seeking (NS) - tendency to be exploratory, and Harm avoidance (HA) - tendency to be cautious. Participants with high NS and low HA (n = 10) assessed by TCI had a different neural response to stress than those with low NS and high HA (n = 10). Event-related desynchronization (ERD) in the beta frequency band was observed only in participants with high NS and low HA in the brain region extending from Brodmann's area 31 (including the posterior cingulate cortex and precuneus) from 200 to 350 ms after the onset of picture presentation in the stress-inducing task. Individual variation in personality traits (NS and HA) was associated with the neural response to mental stress. These findings increase our understanding of the psychological and neural basis of individual differences in the stress response, and will contribute to development of the psychotherapeutic approaches to stress-related disorders.

The relationship between disease activity, quality of life, and personality types in rheumatoid arthritis and ankylosing spondylitis patients

We hypothesized that clinical outcomes might be influenced by personality type (A, B, C, D) in rheumatoid arthritis (RA) and ankylosing spondylitis (AS). One hundred ninety-four patients (104 with RA, 90 with AS) participated in a questionnaire study. We evaluated health-related quality of life (HRQoL) using the Medical Outcome Study Short-Form 36 (SF-36), personality type A/B with the Jenkins Activity Survey, type C with the State-Trait Anger Expression Inventory Anger-in Scale, type D with the Type D Personality Scale, and disease activity with Disease Activity Score with 28 joints for RA and Bath Ankylosing Spondylitis Disease Activity Index for AS. We used Pearson's correlation coefficient, independent samples t tests, and multivariate analyses of variance. In the RA group, type D personality was significantly correlated with 7/12 SF-36 components. AS patients with type D personality had deficits in all SF-36 subscales. Type D was related with higher disease activity in RA and AS. Both RA and AS type C patients had more active disease forms and negatively affected HRQoL subscales. In the RA group, type A personality did not correlate with HRQoL, but it positively influenced pain visual analog scale scores. In AS patients, type A personality was linked with higher HRQoL and with less active disease. Type C and type D personality types were correlated with decreased HRQoL and higher disease activity in RA and AS patients. Type A personality was associated with less active disease and higher HRQoL in AS patients and with less pain in RA patients.

Harm avoidance and childhood adversities in patients with obsessive-compulsive disorder and their unaffected first-degree relatives

OBJECTIVE

The etiology of obsessive-compulsive disorder (OCD) is assumed to involve interactions between genetically determined vulnerability factors and significant environmental features. Here, we aim to investigate how the personality trait harm avoidance and the experience of childhood adversities contribute to OCD.

METHOD

A total of 169 patients with OCD, 157 healthy comparison subjects, and 57 unaffected first-degree relatives of patients with OCD participated in the study. Harm avoidance was assessed using the Temperament and Character Inventory, and the severity of childhood adversities was measured with the Childhood Trauma Questionnaire.

RESULTS

Both patients with OCD and relatives showed elevated levels of harm avoidance compared to controls. Furthermore, patients exhibited significantly higher scores than relatives. This linear pattern was observed throughout all subscales of harm avoidance, and remained stable after controlling for the severity of depressive and obsessive-compulsive symptoms. With regard to childhood adversities, patients with OCD reported higher levels than relatives and controls.

CONCLUSION

Our results provide further evidence for a diathesis-stress model of OCD. While patients and unaffected relatives share elevated levels of harm avoidance, supporting the role of harm avoidance as an endophenotype of OCD, a heightened severity of childhood adversity was only observed in patients. The assumed biological underpinnings of these findings are discussed.

Stress reactivity and personality in extreme sport athletes: The psychobiology of BASE jumpers

This is the first report of the psychobiology of stress in BASE jumpers, one of the most dangerous forms of extreme sport. We tested the hypotheses that indicators of emotional style (temperament) predict salivary cortisol reactivity, whereas indicators of intentional goal-setting (persistence and character) predict salivary alpha-amylase reactivity during BASE jumping. Ninety-eight subjects completed the Temperament and Character Inventory (TCI) the day before the jump, and 77 also gave salivary samples at baseline, pre-jump on the bridge over the New River Gorge, and post-jump upon landing. Overall BASE jumpers are highly resilient individuals who are highly self-directed, persistent, and risk-taking, but they are heterogeneous in their motives and stress reactivity in the Hypothalamic-Pituitary-Adrenal (HPA) stress system (cortisol reactivity) and the sympathetic arousal system (alpha-amylase reactivity). Three classes of jumpers were identified using latent class analysis based on their personality profiles, prior jumping experience, and levels of cortisol and alpha-amylase at all three time points. "Masterful" jumpers (class 1) had a strong sense of self-directedness and mastery, extensive prior experience, and had little alpha-amylase reactivity and average cortisol reactivity. "Trustful" jumpers (class 2) were highly cooperative and trustful individuals who had little cortisol reactivity coincident with the social support they experienced prior to jumping. "Courageous" jumpers (class 3) were determined despite anxiety and inexperience, and they had high sympathetic reactivity but average cortisol activation. We conclude that trusting social attachment (Reward Dependence) and not jumping experience predicted low cortisol reactivity, whereas persistence (determination) and not jumping experience predicted high alpha-amylase reactivity.

Prenatal Stress, Fearfulness, and the Epigenome: Exploratory Analysis of Sex Differences in DNA Methylation of the Glucocorticoid Receptor Gene

Exposure to stress in utero is a risk factor for the development of problem behavior in the offspring, though precise pathways are unknown. We examined whether DNA methylation of the glucocorticoid receptor gene, NR3C1, was associated with experiences of stress by an expectant mother and fearfulness in her infant. Mothers reported on prenatal stress and infant temperament when infants were 5 months old (n = 68). Buccal cells for methylation analysis were collected from each infant. Prenatal stress was not related to infant fearfulness or NR3C1 methylation in the sample as a whole. Exploratory sex-specific analysis revealed a trend-level association between prenatal stress and increased methylation of NR3C1 exon 1F for female, but not male, infants. In addition, increased methylation was significantly associated with greater fearfulness for females. Results suggest an experience-dependent pathway to fearfulness for female infants via epigenetic modification of the glucocorticoid receptor gene. Future studies should examine prenatal stress in a comprehensive fashion while considering sex differences in epigenetic processes underlying infant temperament.

The role of glucocorticoid receptor phosphorylation in the model of negative affective states

OBJECTIVES

To develop a structural equation model of negative affectivity (NA) that involves interaction of glucocorticoid receptor (GR) signaling, personality dimensions and recent stressful life events.

METHODS

Seventy participants - 35 diagnosed with major depression and 35 healthy controls, were enrolled in the study. Morning plasma cortisol levels were determined by chemiluminescent immunometric assays. Molecular parameters (total nuclear and cytoplasmatic GR, nuclear GR phosphorylated at serine 211 (pGR-211) and at serine 226 (pGR-226) and cytoplasmic FKBP51) were analysed from peripheral blood lymphocytes by Western blot. NA, personality dimensions and stressful life events were assessed by self-report instruments.

RESULTS

GR signalling parameters had direct independent effect on measures of NA, with pGR-226 levels showing the strongest correlation, followed by FKBP51 and pGR-211 levels. Neuroticism and extraversion also demonstrated strong independent effect on NA, while recent stressful events did not predict NA directly, but demonstrated a significant effect on personality dimensions. Cortisol, total nuclear GR and total cytoplasmatic GR levels were excluded from the model due to non-significant correlations with NA.

CONCLUSIONS

Negative affectivity is a transdiagnostic factor in vulnerability to affective disorders and possible therapeutic target. Molecular signature of negative affectivity should incorporate GR phosphorylation with other known biological underpinnings.

The relevance of personality assessment in estimating the risk of onset and the outcome of major depressive disorder

In the past two decades, numerous studies have focused on the relationship between the psychobiological model of temperament and character and the development and evolution of major depressive disorder. This interest has been generated primarily because this particular model was developed as a tool for a comprehensive diagnosis of mental disorders. Such a diagnosis model, based on fewer diagnostic categories and a more phenomenological and person oriented approach seems to be supported by more recent research.

The aim of this paper was to review the latest developments in this area, but in the context of the initial development of the psychobiological model of temperament and character, i.e. as a tool for the comprehensive diagnosis of depressed individuals.

Data published so far supports the following observations: (1) high harm avoidance and low self-directedness are risk factors for the development of major depressive disorder, but further research is needed to clearly establish the role of the other dimensions or their facets as predictors for the development of a depressive episode; (2) although some evidence has been obtained so far regarding the use of harm avoidance, novelty seeking, reward dependence and cooperativeness in predicting treatment response in major depressive disorder, further research is needed to clarify and/or to replicate these findings; and (3) data on temperament and character dimensions related to relapse in major depressive disorder are insufficient, although some evidence has been brought to support the hypothesis that high harm avoidance scores, and low self-directedness and novelty seeking scores might serve as predictors; further prospective studies need to be carried out to establish their utility in this respect.

Multidimensional anatomy of 'modern type depression' in Japan: A proposal for a different diagnostic approach to depression beyond the DSM-5

Japan's prototype of depression was traditionally a melancholic depression based on the premorbid personality known as shūchaku-kishitsu proposed by Mitsuzo Shimoda in the 1930s. However, since around 2000, a novel form of depression has emerged among Japanese youth. Called 'modern type depression (MTD)' by the mass media, the term has quickly gained popularity among the general public, though it has not been regarded as an official medical term. Likewise, lack of consensus guidelines for its diagnosis and treatment, and a dearth of scientific literature on MTD has led to confusion when dealing with it in clinical practice in Japan. In this review article, we summarize and discuss the present situation and issues regarding MTD by focusing on historical, diagnostic, psychosocial, and cultural perspectives. We also draw on international perspectives that begin to suggest that MTD is a phenomenon that may exist not only in Japan but also in many other countries with different sociocultural and historical backgrounds. It is therefore of interest to establish whether MTD is a culture-specific phenomenon in Japan or a syndrome that can be classified using international diagnostic criteria as contained in the ICD or the DSM. We propose a novel diagnostic approach for depression that addresses MTD in order to combat the current confusion about depression under the present diagnostic systems.

Childhood maltreatment increases the risk for visceral obesity

OBJECTIVE

The reports regarding the associations between childhood maltreatment (CM) and body fat composition remain heterogeneous in humans although they are indicated in preclinical studies. In addition, the effects of CM subtypes on different types of body fat are unclear. Thus, in this study, the associations between CM and its subtypes with body fat were determined and the potential pathways were explored.

METHODS

The participants were assessed for a history of CM by the Childhood Trauma Questionnaire and were divided into the CM group (with CM exposures) and non-CM group (without CM exposures). Body composition was measured by dual-energy X-ray absorptiometry. Salivary and blood samples were provided by the subjects.

RESULTS

Compared with the non-CM group, subjects with a history of CM had greater visceral fat mass (1,136 ± 160 vs. 836 ± 116 g, P < 0.05) but not total body fat, android fat, body mass index, or waist-to-hip ratio. In addition, subjects with CM had a blunted cortisol awakening response and elevated inflammatory factors. Correlation analysis indicated that CM subtypes had differential effects on visceral adiposity and cortisol awakening response.

CONCLUSIONS

It is suggested by our results that CM exposure is linked with increased visceral fat deposition, and the perturbation of the hypothalamic-pituitary-adrenal axis activity and activation of the immune system may be two potential pathways through which this relationship is explained.

No effects of hydrocortisone and dexamethasone on pain sensitivity in healthy individuals

BACKGROUND

There is some evidence that stress-induced cortisol increase leads to a decrease in pain, while lowering cortisol levels enhances pain sensitivity, but no study has yet investigated both pharmacological enhancement and reduction of cortisol levels in the same individuals.

METHODS

Firstly, we tested in 16 healthy individuals whether the treatment with hydrocortisone and dexamethasone, respectively, results in altered pain thresholds. Secondly, we aimed to test whether hormone effects are different across the pain range by using ratings for pain stimuli with varying intensity; and thirdly, we tested whether cortisol levels influence the discrimination ability for painful stimuli.

RESULTS

Despite substantial effects of dexamethasone and hydrocortisone administration on cortisol levels, no effect of these drugs was seen in terms of pain sensitivity (pain threshold, pain rating, pain discrimination ability), although comprehensively examined. However, in the placebo condition, a significant negative correlation between cortisol and pain thresholds was seen. Similarly, there were also strong negative associations between cortisol levels in the placebo condition and pain thresholds after drug treatment (especially after hydrocortisone).

CONCLUSION

These findings suggest that short-term variations of cortisol do not influence pain sensitivity whereas, in general, high levels of cortisol are associated with increased pain sensitivity, at least for weak to moderate stimuli.

Adrenal steroid hormones and ethanol self-administration in male rhesus macaques

RATIONALE

Hypothalamic-pituitary-adrenal (HPA) axis hormones have neuroactive metabolites with receptor activity similar to ethanol.

OBJECTIVES

The present study related HPA hormones in naïve monkeys to ethanol self-administration.

METHODS

Morning plasma adrenocorticotropic hormone (ACTH), cortisol, deoxycorticosterone (DOC), aldosterone, and dehydroepiandrosterone-sulfate (DHEA-S) were measured longitudinally in male rhesus macaques (Macaca mulatta) induced to drink ethanol followed by access to ethanol (4 % w/v, in water) and water 22 h/day for 12 months.

RESULTS

During ethanol access, DOC increased among non-heavy (average intake over 12 months ≤3.0 g/kg/day, n = 23) but not among heavy drinkers (>3.0 g/kg/day, n = 9); aldosterone was greater among heavy drinkers after 6 months. The ratio of DOC/aldosterone decreased only among heavy drinkers after 6 or12 months of ethanol self-administration. ACTH only correlated significantly with DHEA-S, the ratio of cortisol/DHEA-S and DOC after the onset of ethanol access, the former two just in heavy drinkers. Baseline hormones did not predict subsequent ethanol intake over 12 months, but baseline DOC correlated with average blood-ethanol concentrations (BECs), among all monkeys and heavy drinkers as a group. During ethanol access, aldosterone and DOC correlated and tended to correlate, respectively, with 12-month average ethanol intake.

CONCLUSIONS

Ethanol self-administration lowered ACTH and selectively altered its adrenocortical regulation. Mineralocorticoids may compensate for adrenocortical adaptation among heavy drinkers and balance fluid homeostasis. As DOC was uniquely predictive of future BEC and not water intake, to the exclusion of aldosterone, GABAergic neuroactive metabolites of DOC may be risk factors for binge drinking to intoxication.

Cortisol awakening response in patients with anorexia nervosa or bulimia nervosa: relationships to sensitivity to reward and sensitivity to punishment

BACKGROUND

Sensitivity to punishment (SP) and sensitivity to reward (SR) are personality characteristics that may have relevance for the pathophysiology of eating disorders (EDs). Moreover, personality characteristics are known to modulate the activity of the hypothalamus-pituitary-adrenal (HPA) axis, which is the main component of the endogenous stress response system. As stress has been implicated in the aetiology and the maintenance of EDs, we aimed to study the HPA axis activity in relation to SP and SR, as conceptualized by Gray's reinforcement sensitivity theory (RST), in patients with anorexia nervosa (AN) or bulimia nervosa (BN).

METHOD

Twenty-five women with AN, 23 women with BN and 19 healthy women volunteered for the study. HPA axis activity was assessed by measurement of the salivary cortisol awakening response (CAR). The subjects' SP and SR were measured by the behavioural inhibition system (BIS)/behavioural approach system (BAS) scales.

RESULTS

The CAR was significantly enhanced in AN patients, but not in BN patients, compared to healthy women. The CAR correlated significantly with BAS measures, negatively in healthy controls and positively in binge-purging AN patients and BN women. SP, measured by the BIS scale, was higher in patients than in controls.

CONCLUSIONS

These findings confirm the occurrence of an enhanced activity of the HPA axis in symptomatic AN, but not in symptomatic BN, and show for the first time that the CAR is associated with SR, as conceptualized by the RST, negatively in healthy subjects but positively in binge-purging ED patients.

Oxytocin's role in anxiety: a critical appraisal

A growing literature suggests that the oxytocin (OT) system may play a role in human anxiety states, anxiety-related traits, and moreover, that this system may be a target for the development of novel anxiolytic treatments. However, studies of OT's acute and chronic effects on various aspects of anxiety have produced mixed results. In this forward-looking review, we discuss the myriad phenomena to which the term "anxiety" is applied in the OT literature and the problem this presents developing a coherent picture of OT's role in anxiety. We then survey several different fields of research that support the role of the OT system in human anxiety, including evolutionary perspectives, translational and neuroimaging research, genetic studies, and clinical trials of intranasal OT. As an outgrowth of this data, we propose a "bowtie" model of OT's role at the interface of social attachment and anxiety. We next direct attention to understudied brain regions and neural circuits which may be important to study in OT experiments in humans anxiety disorders. Finally, we conclude by proposing questions and priorities for studying both the clinical potential of OT in anxiety, as well as mechanisms that may underlie this potential. Crucially, these priorities include targeted proof-of-concept clinical trials of IN OT in certain anxiety disorders, including investigations of individual moderators of OT's anxiolytic effects (i.e. sex, genetic factors, and early experience). This article is part of a Special Issue entitled Oxytocin and Social Behav.

Relationship of temperament and character with cortisol reactivity to the combined dexamethasone/CRH test in depressed outpatients

BACKGROUND

Evidence shows that depression is associated with hypothalamic-pituitary-adrenal (HPA) axis hyperactivation, although such findings are not entirely unequivocal. In contrast, various psychiatric conditions, including atypical depression, are associated with hypocortisolism. Another line of research has demonstrated that personality is associated with HPA axis alteration. It is thus hypothesized that different personality pathology in depression would be associated with distinct cortisol reactivity.

METHODS

Eighty-seven outpatients with DSM-IV major depressive disorder were recruited. Personality was assessed by the temperament and character inventory (TCI). HPA axis reactivity was measured by the combined dexamethasone (DEX)/corticotropin-releasing hormone (CRH) test. According to our previous studies, two subgroups were considered based on their cortisol responses to the DEX/CRH test: incomplete-suppressors whose cortisol response was exaggerated and enhanced-suppressors whose cortisol response was blunted.

RESULTS

The analysis of covariance, controlling for age, gender and symptom severity, revealed that incomplete-suppressors scored significantly higher on cooperativeness than enhanced-suppressors (p=0.002). A multivariate stepwise logistic regression analysis predicting the cortisol suppression pattern from the seven TCI dimensions, controlling for age, gender and symptom severity, revealed that lower cooperativeness (p=0.001) and higher reward dependence (p=0.018) were significant predictors toward enhanced suppression.

LIMITATIONS

The neuroendocrine challenge test was administered only once, based on a simple test protocol.

CONCLUSIONS

Our findings suggest that (personality-related) subtypes of depression might be differentiated based on the different pattern of cortisol reactivity. Future studies are warranted to further characterize the HPA axis alteration in relation to various subtypes of depression.

Possible rheumatoid arthritis subtypes in terms of rheumatoid factor, depression, diagnostic delay and emotional expression: an exploratory case-control study

Introduction

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been implicated in the pathology of rheumatoid arthritis (RA), particularly as vulnerable personality types are exposed to chronic stress. Emotions are powerful modulators of stress responses. However, little is known about whether patients with RA process emotions differently to matched controls. In this study we: 1) assessed whether the trait emotional intelligence (trait EI) scores of patients with RA differ from healthy controls at the facet level; 2) explored any subgroups in RA, in terms of trait EI and common risk factors.

Methods

A total of 637 patients with RA were compared to 496 controls on the trait EI Questionnaire (TEIQue). RA subgroups were explored in terms of trait EI, rheumatoid factor status (RF+/-), depression and time from onset of symptoms until diagnosis (diagnostic delay).

Results

The RA group rated themselves lower on Adaptability, Stress-management, Emotion management, Self-esteem, Sociability, Assertiveness, Impulsiveness and Well-being, and higher on Empathy and Relationships than healthy controls. The RF- subtype reported more time with depression (25.2 vs. 11.3 months), a longer diagnostic delay (3.0 vs. 1.7 years), and greater emotional expression (5.15 vs. 4.72), than the RF+ subtype. These differences were significant at the P <0.05 level, but not following strict Bonferroni corrections and should therefore be treated as indicative only. RF- patients with a longer diagnostic delay reported depression lasting three times longer (42.7 months), when compared to three other subtypes (11.0 to 12.7 months).

Conclusions

RA patients and controls differ in their emotion-related personality traits, as operationalized by trait EI. These differences may make people with RA more susceptible to chronic stress and HPA-axis dysregulation. RA may be a highly heterogeneous illness where at least two subtypes may be characterized by personality, psychiatric and immunological differences. RF- status, as well as diagnostic delay and emotional expression, may predict future risk of depression. Research on the causes of RA could benefit from a systems science approach.

Novelty-seeking and avoidant coping strategies are associated with academic stress in Korean medical students

High levels of stress and depression in medical students is raising concern. In this study, we sought to identify coping strategies and other factors influencing academic stress in medical students. We enrolled 157 students from the University of Ulsan College of Medicine, Korea, in November, 2010. We used the Medical Stress Scale, Temperament and Character Inventory, Hamilton Depression Scale, Beck Depression Inventory, and Coping Response Inventory to assess psychological parameters. We used Pearson's correlation and linear regression analyses to analyze the data. Novelty-seeking, self-directedness, cooperativeness, coping strategy, and depression scale scores all correlated significantly with stress level. Linear regression analysis indicated that students who are novelty-seeking, likely to use avoidant coping strategies, and unlikely to use active-cognitive and active-behavioral strategies tend to have higher stress levels. Reduction of stress in medical students may be achieved through evaluation of coping strategies and personality features and use of interventions to promote active coping strategies.

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.

Personality traits in rats predict vulnerability and resilience to developing stress-induced depression-like behaviors, HPA axis hyper-reactivity and brain changes in pERK1/2 activity

Emerging evidence indicates that certain behavioral traits, such as anxiety, are associated with the development of depression-like behaviors after exposure to chronic stress. However, single traits do not explain the wide variability in vulnerability to stress observed in outbred populations. We hypothesized that a combination of behavioral traits might provide a better characterization of an individual's vulnerability to prolonged stress. Here, we sought to determine whether the characterization of relevant behavioral traits in rats could aid in identifying individuals with different vulnerabilities to developing stress-induced depression-like behavioral alterations. We also investigated whether behavioral traits would be related to the development of alterations in the hypothalamic-pituitary-adrenal axis and in brain activity - as measured through phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2)--in response to an acute stressor following either sub-chronic (2 weeks) or chronic (4 weeks) unpredictable stress (CUS). Sprague-Dawley rats were characterized using a battery of behavioral tasks, and three principal traits were identified: anxiety, exploration and activity. When combined, the first two traits were found to explain the variability in the stress responses. Our findings confirm the increased risk of animals with high anxiety developing certain depression-like behaviors (e.g., increased floating time in the forced swim test) when progressively exposed to stress. In contrast, the behavioral profile based on combined low anxiety and low exploration was resistant to alterations related to social behaviors, while the high anxiety and low exploration profile displayed a particularly vulnerable pattern of physiological and neurobiological responses after sub-chronic stress exposure. Our findings indicate important differences in animals' vulnerability and/or resilience to the effects of repeated stress, particularly during initial or intermediate levels of stress exposure, and they highlight that the behavioral inhibition profile of an animal provides a particular susceptibility to responding in a deleterious manner to stress.

Childhood stressful events, HPA axis and anxiety disorders

Anxiety disorders are among the most common of all mental disorders and their pathogenesis is a major topic in psychiatry, both for prevention and treatment. Early stressful life events and alterations of hypothalamic pituitary adrenal (HPA) axis function seem to have a significant role in the onset of anxiety. Existing data appear to support the mediating effect of the HPA axis between childhood traumata and posttraumatic stress disorder. Findings on the HPA axis activity at baseline and after stimuli in panic disordered patients are inconclusive, even if stressful life events may have a triggering function in the development of this disorder. Data on the relationship between stress, HPA axis functioning and obsessive-compulsive disorder (OCD) are scarce and discordant, but an increased activity of the HPA axis is reported in OCD patients. Moreover, normal basal cortisol levels and hyper-responsiveness of the adrenal cortex during a psychosocial stressor are observed in social phobics. Finally, abnormal HPA axis activity has also been observed in generalized anxiety disordered patients. While several hypothesis have attempted to explain these findings over time, currently the most widely accepted theory is that early stressful life events may provoke alterations of the stress response and thus of the HPA axis, that can endure during adulthood, predisposing individuals to develop psychopathology. All theories are reviewed and the authors conclude that childhood life events and HPA abnormalities may be specifically and transnosographically related to all anxiety disorders, as well as, more broadly, to all psychiatric disorders.

Can onset and recovery in depression be predicted by temperament? A systematic review and meta-analysis

BACKGROUND

Behavioural inhibition and more specifically harm avoidance temperament dimension (HA) has been found to be associated with depression. Temperament and Character Inventory (TCI) by Cloninger et al. is the most widely used instrument in the assessment of temperament. The aims of the present study were to explore 1) if current or future depressive symptoms in non-clinical adult sample can be explained by TCI temperament dimensions, and 2) if recovery from major depression (MDD) during the acute phase of treatment is predictable by TCI temperament dimensions.

METHOD

Literature search from eight databases. Systematic review and meta-analysis.

RESULTS

High HA was associated with current depressive symptoms in 11/12 studies and with depressive trait in 3/4 studies. In MDD studies, a consistent negative change in HA was found during treatment and this change was even more clearly associated with treatment response.

LIMITATIONS

The studies with general population samples were heterogeneous in methodology. Most of the intervention studies were of case-control design.

CONCLUSIONS

HA is indisputably associated with the risk and treatment response in depression.

A placebo-controlled study of sertraline's effect on cortisol response to the dexamethasone/corticotropin-releasing hormone test in healthy adults

RATIONALE

The dexamethasone/corticotropin-releasing hormone (Dex/CRH) test is a neuroendocrine probe involving serial blood sampling of cortisol during a standardized pharmacological challenge without inducing psychological distress in humans. Some past studies in depressed patients have shown a "normalization" or decrease in cortisol response to the Dex/CRH test following successful treatment with an antidepressant. Studies in nondepressed healthy adult samples have also shown aberrant cortisol reactivity to be associated with depression risk factors. These findings prompted research into the use of the Dex/CRH test as a tool for developing antidepressant drugs.

OBJECTIVES

In this study, the Dex/CRH test was evaluated with regard to its potential utility for drug development in nonclinical samples.

METHODS

The Dex/CRH test was administered before and after 6 weeks of blinded treatment with either sertraline 100 mg/day or matching placebo in 22 healthy adults (13 women, nine men).

RESULTS

Cortisol response to the Dex/CRH test increased following treatment with standard doses of sertraline, compared to placebo, after controlling for age and sex.

CONCLUSIONS

The observed pattern of change contrasts with results from published studies in depressed patients and with our initial hypothesis.

Cloninger's temperament traits and inherited long QT syndrome

OBJECTIVE

The long QT syndrome (LQTS) is an inherited cardiac disorder which predisposes the mutation carrier to ventricular arrhythmias that can lead to sudden death. The objective of the present study was to examine the association between the symptom status of congenital long QT syndrome mutation carriers and their temperament.

METHODS

The study subjects included 587 LQTS mutation carriers from the Finnish LQTS registry, and 2056 individuals from a database study, the Young Finns Study (YFS), representing general population and serving as control subjects. The LQTS subjects were divided into symptomatic (n=259) and asymptomatic (n=328) groups, according to their history of arrhythmic events. Temperament was assessed using the Cloninger's Temperament and Character Inventory (TCI), assessing novelty seeking, harm avoidance and reward dependence.

RESULTS

Congenital long QT syndrome mutation carriers had a higher harm avoidance (HA) than those representing the general population (2.77 vs. 2.61, p<.001, η²=0.011). Symptomatic and asymptomatic LQTS mutation carriers did not differ from one another in any of the three Cloninger's temperament traits. HA was significantly higher in women (2.72 vs. 2.54, p<0.001 η²=0.017).

CONCLUSIONS

LQTS mutation carriers may have higher stress proneness because of their high HA, which in turn may predispose them to the effects of environmental loading and thus increase the risk of arrhythmias.

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.

Personality and obesity across the adult life span

Personality traits contribute to health outcomes, in part through their association with major controllable risk factors, such as obesity. Body weight, in turn, reflects our behaviors and lifestyle and contributes to the way we perceive ourselves and others. In this study, the authors use data from a large (N = 1,988) longitudinal study that spanned more than 50 years to examine how personality traits are associated with multiple measures of adiposity and with fluctuations in body mass index (BMI). Using 14,531 anthropometric assessments, the authors modeled the trajectory of BMI across adulthood and tested whether personality predicted its rate of change. Measured concurrently, participants higher on Neuroticism or Extraversion or lower on Conscientiousness had higher BMI; these associations replicated across body fat, waist, and hip circumference. The strongest association was found for the impulsivity facet: Participants who scored in the top 10% of impulsivity weighed, on average, 11Kg more than those in the bottom 10%. Longitudinally, high Neuroticism and low Conscientiousness, and the facets of these traits related to difficulty with impulse control, were associated with weight fluctuations, measured as the variability in weight over time. Finally, low Agreeableness and impulsivity-related traits predicted a greater increase in BMI across the adult life span. BMI was mostly unrelated to change in personality traits. Personality traits are defined by cognitive, emotional, and behavioral patterns that likely contribute to unhealthy weight and difficulties with weight management. Such associations may elucidate the role of personality traits in disease progression and may help to design more effective interventions.

Baseline 'state anxiety' influences HPA-axis sensitivity to one sham-controlled HF-rTMS session applied to the right dorsolateral prefrontal cortex

Although negative results have been reported, an important aspect of the physiology of repetitive transcranial magnetic stimulation (rTMS) could be related to the endocrinological response of the hypothalamic-pituitary-adrenal (HPA) axis, such as cortisol secretion. Because endocrinological responses are influenced by anxiety states, this could influence the effect of rTMS in healthy individuals. In this sham-controlled, "single blind" crossover study, we examined whether one session of HF-rTMS could affect the HPA-system, when taking into account individual state anxiety scores based on the State-Trait Anxiety Inventory (STAI). Twenty-four healthy rTMS naïve females received one sham-controlled high frequency (HF)-rTMS session delivered on the right dorsolateral prefrontal cortex (DLPFC). The Profile of Mood States (POMS) questionnaire, together with salivary cortisol samples, was collected before, just after and 30 min post HF-rTMS. To examine whether state anxiety could influence endocrinological outcome measurements, we administered the STAI-state just before each HF-rTMS experiment started. Based on the POMS questionnaire, no mood changes were observed. Without taking individual state anxiety scores into account, one sham-controlled right-sided HF-rTMS session did not influence the HPA-system. When taking into account individual STAI-state scores, we found that healthy women scoring higher on the STAI-state displayed a significantly more sensitive HPA-system, resulting in salivary cortisol concentration increases after real HF-rTMS, compared to those scoring lower on this anxiety scale. Our results indicate that healthy women scoring high on state anxiety display a more sensitive HPA-system when receiving one right-sided HF-rTMS session. Our findings suggest that the incorporation of individual anxiety states in experimental rTMS research could add further information about its neurobiological influences on the HPA-system.

Relationships between psychological distress, coping styles, and HPA axis reactivity in healthy adults

Psychological distress and coping styles have been suggested to relate to altered function in the hypothalamic-pituitary-adrenal (HPA) axis, although there remains much to be understood about their relationships. High and low cortisol levels (or reactivity) both represent HPA axis dysfunction, with accumulated evidence suggesting that they are linked to different types of psychopathology. The dexamethasone (DEX)/corticotropin-releasing hormone (CRH) test has been extensively used to identify HPA axis abnormalities in various psychiatric conditions including mood disorders; however, the possible associations of psychological distress and coping styles with HPA axis function have not been well documented using this test. Here, we examined the relationships of HPA axis reactivity as measured by the DEX/CRH test with subjectively perceived psychological distress and coping styles, both of which were assessed with self-report questionnaires, in 121 healthy volunteers. Subjects were divided into three groups by the cortisol suppression pattern, namely the incomplete-suppressors (DST-Cortisol ≥ 5 μg/dL or DEX/CRH-Cortisol ≥ 5 μg/dL), moderate-suppressors (DST-Cortisol < 5 μg/dL and 1 μg/dL ≤ DEX/CRH -Cortisol < 5 μg/dL), and enhanced-suppressors (DST-Cortisol < 5 μg/dL and DEX/CRH-Cortisol < 1 μg/dL). The enhanced-suppressors showed significantly higher scores in obsessive-compulsive, interpersonal sensitivity and anxiety symptoms and significantly more frequent use of avoidant coping strategy, compared to the other two groups. These results point to the important role of enhanced suppression of cortisol, or blunted cortisol reactivity, in non-clinical psychopathology such as avoidant coping strategy and greater psychological distress.

Disparate effects of feeding on core body and adipose tissue temperatures in animals selectively bred for Nervous or Calm temperament

In addition to homeostatic regulation of body mass, nonhomeostatic factors impact on energy balance. Herein we describe effects of temperament on adipose and core body temperatures in sheep. Animals were genetically selected for Nervous or Calm traits. We characterized the effects of 1) high- and low-energy intake and maintenance feeding, 2) meal anticipation, and 3) adrenocorticotropin challenge on core body and adipose temperatures. Temperature measurements (5 min) were made using a thermistor inserted into the carotid artery (core body) and a probe in the retroperitoneal fat. An imposed feeding window was used to establish postprandial elevations in temperature. Fat tissue was taken from retroperitoneal and subcutaneous regions for real-time PCR analyses. We demonstrate that innate differences in temperament impact on adipose and core body temperatures in response to various dietary and evocative stimuli. In response to homeostatic cues (low-energy intake and maintenance feeding) core body temperature tended to be higher in Calm compared with Nervous animals. In contrast, in response to nonhomeostatic cues, Nervous animals had higher anticipatory thermogenic responses than Calm animals. Expression of uncoupling protein (UCP)-1 and -2 mRNA were higher in retroperitoneal tissue than in subcutaneous tissue, but UCP3 and leptin mRNA levels were similar at both sites; expression of these genes was similar in Nervous and Calm animals. There were no differences in stress responsiveness. We conclude that temperament differentially influences adipose thermogenesis and the regulation of core body temperature in responses to both homeostatic and nonhomeostatic stimuli.

Behavioral adjustment in a community sample of boys: links with basal and stress-induced salivary cortisol concentrations

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been observed in association with internalizing symptoms and is thought to be involved in the pathogenesis of depression and some anxiety disorders. This study examined basal and stress-induced cortisol concentrations in relation to internalizing and externalizing symptoms in a racially mixed community sample of 102 8-11-year-old boys. Afternoon basal cortisol concentrations were positively correlated with measures of internalizing behavior problems, social problems, and emotionality. Greater change in cortisol across a home-visit challenge task was also significantly associated with internalizing behaviors and social problems, as well as attention and thought problems. The implications of these findings and how they may relate to the pathogenesis of emotional and behavioral problems are discussed.

High neuroticism and low conscientiousness are associated with interleukin-6

BACKGROUND

High Neuroticism and low Conscientiousness are frequently implicated in health-risk behaviors, such as smoking and overeating, as well as health outcomes, including mortality. Their associations with physiological markers of morbidity and mortality, such as inflammation, are less well documented. The present research examines the association between the five major dimensions of personality and interleukin-6 (IL-6), a pro-inflammatory cytokine often elevated in patients with chronic morbidity and frailty.

METHOD

A population-based sample (n=4923) from four towns in Sardinia, Italy, had their levels of IL-6 measured and completed a comprehensive personality questionnaire, the NEO-PI-R. Analyses controlled for factors known to have an effect on IL-6: age; sex; smoking; weight; aspirin use; disease burden.

RESULTS

High Neuroticism and low Conscientiousness were both associated with higher levels of IL-6. The findings remained significant after controlling for the relevant covariates. Similar results were found for C-reactive protein, a related marker of chronic inflammation. Further, smoking and weight partially mediated the association between impulsivity-related traits and higher IL-6 levels. Finally, logistic regressions revealed that participants either in the top 10% of the distribution of Neuroticism or the bottom 10% of conscientiousness had an approximately 40% greater risk of exceeding clinically relevant thresholds of IL-6.

CONCLUSIONS

Consistent with the literature on personality and self-reported health, individuals high on Neuroticism or low on Conscientiousness show elevated levels of this inflammatory cytokine. Identifying critical medical biomarkers associated with personality may help to elucidate the physiological mechanisms responsible for the observed connections between personality traits and physical health.

Higher overcommitment to work is associated with higher plasma cortisol but not ACTH responses in the combined dexamethasone/CRH test in apparently healthy men and women

BACKGROUND

Overcommitment (OC) is a pattern of excessive striving that has been associated with alterations in the hypothalamus-pituitary-adrenal (HPA) system. To investigate whether overcommitment is associated with alterations in HPA system function we measured cortisol and adrenocorticotropin (ACTH) release in response to the combined dexamethasone/CRH test.

METHODS

We recruited 92 men and 108 women of a wide range of OC scores including the minimum (6) and maximum (24) of possible OC scores (mean+/-SEM: 13.25+/-.27). We repeatedly measured plasma cortisol and ACTH levels in the combined dexamethasone/CRH test after injection of 100mul CRH preceded by administration of 1.5mg dexamethasone the night before. Moreover, we assessed depressive symptoms (Beck Depression Inventory, BDI) and work stress (effort-reward-imbalance, ERI).

RESULTS

Independent of age and gender, higher OC was associated with higher repeated cortisol (interaction time-by-OC: p=.014, f=.15) but not ACTH (p=.22) secretion in the combined dexamethasone/CRH test. Similarly, higher cortisol (beta=.16, p=.029, R(2)=.02) but not ACTH (p=.47) increase following CRH injection was predicted by higher OC. Depressive symptoms (BDI score) and work stress scores (effort-reward-ratio) did not relate to neuroendocrine responses to the dexamethasone/CRH test. Controlling for depressive symptoms and work stress scores in addition to age and gender did not change results. OC was not associated with ACTH or cortisol pre-test levels.

DISCUSSION

Whereas OC was not associated with alterations in negative feedback sensitivity after dexamethasone administration, our findings indicate that with increasing OC scores, a higher reactivity of the adrenal cortex together with a normal reactivity of the pituitary is observed following subsequent stimulation by CRH injection.

Emotionally stable, intelligent men live longer: the Vietnam Experience Study cohort

OBJECTIVES

To determine whether neuroticism, cognitive ability, and their interaction predicted mortality and to test whether neuroticism or cognitive ability effects were mediated by socioeconomic status (SES), physical health, mental health, or health behaviors.

METHODS

Participants were 4200 men followed up for > 15 years. Participants took part in telephone interviews and medical and psychological evaluations. The neuroticism measure was based on the Minnesota Multiphasic Personality Inventory, which was administered during the psychological examination. Cognitive ability was measured via the Army General Technical Test given at induction and Wechsler Adult Intelligence Scale subtests administered during the psychological examination, approximately 17 years later. We used covariance structure modeling to analyze the data because it enabled us to conduct Cox proportional hazards analyses with latent variables and mediator variables.

RESULTS

Even after adjusting for age, ethnicity, and marital status, high neuroticism and low cognitive ability were independent mortality risk factors. A significant interaction indicated that participants high in neuroticism and low in cognitive ability were particularly at risk. In a second series of models, we examined whether education, income, seven physical health measures, two mental health measures, drinking, and smoking were related to mortality. SES and physical health variables attenuated the effect of cognitive ability but not that of neuroticism. A third series of models revealed that cognitive ability was related to mortality via its direct effects on income and health.

CONCLUSIONS

The effects of high neuroticism, low cognitive ability, and their interaction predict mortality. Cognitive ability effects are mediated by health, income, and education.