Neuroticism, depressive symptoms, and serum BDNF.

OBJECTIVE: Animal models and clinical studies suggest that brain-derived neurotrophic factor (BDNF) is involved in the pathophysiology of depression. We test whether serum and plasma levels of BDNF are associated with trait neuroticism and its facets and with state measures of depressive symptoms. METHODS: In a community-based cohort (N = 2099), we measured serum and plasma BDNF concentrations and administered the Revised NEO Personality Inventory and the Center for Epidemiological Studies Depression Scale. Covariates included age, sex, cigarette smoking, obesity, and antidepressant use. RESULTS: Serum BDNF concentrations were inversely related to neuroticism (r = -0.074, p < .001), in particular the depression facet (r = -0.08, p < .001). Lower BDNF concentrations were also associated with severe depressive symptoms (Center for Epidemiological Studies Depression Scale ≥ 28; odds ratio = 0.906; 95% confidence interval = 0.851-0.965). The association of serum BDNF with neuroticism was independent of depressive symptoms, indicating that serum BDNF might represent a biological correlate of neuroticism and not just of transient depressive states. Plasma BDNF was not associated with measures of depression. CONCLUSIONS: Our study suggests that lower serum BDNF is associated with both a dispositional vulnerability to depression and acute depressive states in the general population.

Relationship between adiposity, emotional status and eating behaviour in obese women: role of inflammation.

BACKGROUND: Obesity is characterized by chronic low-grade inflammation that may lead to emotional distress and behavioural symptoms. This study assessed the relationship between adiposity, low-grade inflammation, eating behaviour and emotional status in obese women awaiting gastric surgery and investigated the effects of surgery-induced weight loss on this relationship. METHOD: A total of 101 women with severe or morbid obesity awaiting gastric surgery were recruited. Assessments were performed before and at 1 year post-surgery and included the measurement of neuroticism and extraversion using the revised Neuroticism-Extraversion-Openness personality inventory (NEO-PI-R) and eating behaviour using the Three-Factor Eating Questionnaire (TFEQ). Blood samples were collected for the measurement of serum inflammatory markers [interleukin-6 (IL-6), high-sensitive C-reactive protein (hsCRP)] and adipokines (leptin, adiponectin). RESULTS: At baseline, body mass index (BMI) was positively correlated with inflammatory markers and adipokines. Regression analyses adjusting for age and diabetes revealed that baseline concentrations of IL-6 and hsCRP were associated with the depression and anxiety facets of neuroticism, with higher inflammation predicting higher anxiety and depression. This association remained significant after adjusting for BMI. Gastric surgery induced significant weight loss, which correlated with reduced inflammation. After controlling for BMI variations, decreases in inflammatory markers, notably hsCRP, were associated with reduced anxiety and TFEQ-cognitive restraint scores. CONCLUSIONS: These findings indicate strong associations between adiposity, inflammation and affectivity in obese subjects and show that surgery-induced weight loss is associated concomitantly with reduced inflammation and adipokines and with significant improvement in emotional status and eating behaviour. Inflammatory status appears to represent an important mediator of emotional distress and psychological characteristics of obese individuals.

Neuroticism but not omega-3 fatty acid levels correlate with early responsiveness to escitalopram.

BACKGROUND: Omega-3 fatty acid (O3FA) levels and dimensional personality measures have been associated with major depression and the course of depressive illness. We sought to study the utility of O3FA levels and dimensional personality measures as predictors of early improvement with escitalopram. METHODS: Twenty-four participants were enrolled in an open-label trial of escitalopram 10 mg/d for 4 weeks. Baseline erythrocyte O3 levels and dimensional personality assessments were obtained. RESULTS: Using a conservative, intention-to-treat analysis, baseline neuroticism (r = -0.57; P = .007), as measured by the Revised NEO Personality Inventory but not erythrocyte O3 levels, was correlated with improvements on escitalopram. A facet analysis of the neuroticism domain showed the relationship with antidepressant response to be focused on trait anxiety (r = -0.65; P = .002). CONCLUSIONS: Anxiety may have important prognostic implications on subsequent response to selective serotonin reuptake inhibitors, such as escitalopram.

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.

Whole blood BDNF levels in healthy twins discordant for affective disorder: association to life events and neuroticism.

BACKGROUND: Depression has been associated with decreased blood BDNF concentrations; but it is unclear if low blood BDNF levels are a state or a trait marker of depression. METHODS: We investigated blood BDNF concentrations in a twin population including both subjects highly predisposed and protected against affective disorder. Whole blood assessed for BDNF concentrations and correlated to risk status, neuroticism, and number of stressful life events. RESULTS: Between the groups, we found no significant difference in whole blood BDNF levels. Women at high-risk for depression who had experienced three or more recent stressful events (n=26) had decreased whole blood BDNF levels compared to high-risk women with two or less recent stressful events (n=35), 21.6+/-7.0 vs. 18.5+/-4.1 ng/ml, respectively, (p<0.05). No such association was found in low-risk women or in men. In men, however, low neuroticism scores and two or less recent stressful events were associated with decreased whole blood BDNF levels (n=50, p<0.05). LIMITATIONS: The cross-sectional design limits the possibility of drawing firm conclusions on causatility of the findings. CONCLUSION: The genetic risk of developing depression does not translate directly into whole blood BDNF levels. In females who are genetically disposed for depression and subjected to recent stressful life events whole blood BDNF levels are lower.

High omega-6 and low omega-3 fatty acids are associated with depressive symptoms and neuroticism.

OBJECTIVE: To examine the concentrations of omega-3 and omega-6 polyunsaturated fatty acids in serum obtained from nonpatient community volunteers not selected for hypercholesterolemia. Previously we reported that the relative concentrations of omega-3 and omega-6 polyunsaturated fatty acids in serum covary with depressive symptomatology and neuroticism in hypercholesterolemic adults. METHODS: A total of 116 adults without current Axis I psychopathology completed the Beck Depression Inventory (BDI) and the NEO Personality Inventory--Revised (NEO-PI-R). Fasting serum phospholipid eicosapentaenoic (EPA), docosahexaenoic (DHA), and arachidonic acid (AA) were determined (% of total pool). RESULTS: Higher AA and AA:EPA ratio, adjusted for age, gender, and race, were associated with greater depressive symptomatology (BDI score of >or=10). Lower EPA, and higher AA, AA:EPA ratio and AA:DHA ratio were associated with greater NEO-PI-R Neuroticism. The six Neuroticism subscales were each associated with two or more fatty acid measurements. CONCLUSIONS: In conjunction with other reports, these findings suggest that the omega-3 and omega-6 fatty acids are related to negative affect at both the symptom and trait levels.

Cortisol and adrenocorticotropic hormone responses to naloxone in subjects with high and low neuroticism.

BACKGROUND: Neuroticism is a highly heritable personality trait that is a risk factor for certain affective and anxiety disorders. Studies link neuroticism with alterations in the Hypothalamic-Pituitary-Adrenal (HPA) stress response. We interrogated HPA axis dynamics as a function of neuroticism, employing the opioid receptor antagonist, naloxone. METHODS: Subjects were assigned to either high or low neuroticism groups on the basis of Revised Neuroticism, Extraversion, Openness Personality Inventory (NEO-PI-R) scores and received naloxone hydrochloride (0, 125 microg/kg, and 375 microg/kg). Serum adrenocorticotropic hormone (ACTH) and cortisol levels were monitored. RESULTS: Significant, dose-dependent differences in cortisol response were observed between neuroticism groups, whereas no differences were observed in ACTH. The low neuroticism group demonstrated a dose-dependent cortisol response with a plateau at the 125 microg/kg dose of naloxone. In contrast, the high neuroticism group demonstrated a graded cortisol response to all doses of naloxone. CONCLUSIONS: These findings show that neuroticism is associated with altered cortisol responses to opioid receptor blockade, suggesting that alterations in HPA axis function already exist in persons at increased risk for certain depressive and anxiety disorders.

Temperament and hypothalamic-pituitary-adrenal axis function in healthy adults.

BACKGROUND: Traits such as behavioral inhibition and neuroticism have been linked to the development of mood and anxiety disorders. Hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis, a manifestation of the stress response, is often seen in major depression and has also been demonstrated in animals and humans with inhibited temperaments. A recent study found HPA hyperactivity in adults with high levels of neuroticism. The present study investigated associations of temperament and HPA function in 31 healthy adults. METHODS AND MATERIALS: Subjects completed diagnostic interviews, questionnaires, and the dexamethasone-/corticotropin-releasing hormone (Dex/CRH) test. Temperament was assessed using the Tridimensional Personality Questionnaire (TPQ). RESULTS: Novelty Seeking was inversely related to plasma cortisol concentrations in the Dex/CRH test. Harm Avoidance and Reward Dependence were not significantly associated with cortisol responses in the Dex/CRH test. The results were not accounted for by psychiatric symptoms or a history of stress or childhood maltreatment. CONCLUSIONS: These findings are consistent with previous reports associating temperament factors with HPA axis hyperactivity. Further work is needed to replicate these observations and determine whether HPA axis dysfunction might account for some of the previously reported association of personality factors with mood and anxiety disorders.

High neuroticism and depressive temperament are associated with dysfunctional regulation of the hypothalamic-pituitary-adrenocortical system in healthy volunteers.

OBJECTIVE: Elevated neuroticism, depressive temperament and dysfunctional regulation of the hypothalamic-pituitary-adrenocortical (HPA) system are considered as risk factors for unipolar depression. An interaction of these vulnerability factors was suggested, but controversially discussed. In absence of other informative studies we set out for a replication test and for elucidation of the underlying mechanism. METHOD: Ninety-two subjects recruited in the community-performed assessments of personality and temperament as well as measurement of HPA function with the dexamethasone/corticotropin-releasing hormone (Dex/CRH) test. RESULTS: Cortisol levels subsequent to Dex/CRH challenge were associated with neuroticism; high-neuroticism subjects revealed a higher HPA activation. This difference was mainly because of male subjects >/=25 years. A similar relationship was observed for depressive temperament. CONCLUSION: This constellation may propose that HPA dysregulation is the endocrinological basis for neuroticism and depressive temperament; this result supports the view that distinct personality factors and HPA vulnerability interact in mediating depression.

[Neurotic disorders: clinical and biochemical comparison]. / Nevroticheskie rasstroistva: kliniko-biokhimicheskie paralleli.

Parameters of lipid peroxidation (LP) and those of the lipid composition of membrane erythrocytes were examined in 22 patients with neurotic disorders (adaptation disorders and neurasthenia). 45 healthy donors were in the control group. The deposition of cholesterol and of lysophosphotidylcholine as well as a reduced mean level of phosphatidylethanolamine were observed in the erythrocyte membrane of patients with neuroses. An increased mean content of malonic dialdehyde and of diene conjugates in the erythrocyte membrane and reduced mean values of the activity of antioxidant catalase enzyme were detected. However, the cluster analysis made it possible to establish an intensification of LP processes only in patients with the disease duration below three months. It is not ruled out that the reason of the detected heterogeneity of changed parameters characterizing the structural-and-metabolic status of erythrocytes in patients with neurotic disorders is related with differing natures of the adaptation abilities of the body under the influence of various stress factors.

[Principles of changes of structural organization of cell membranes and functional properties of erythrocytes in neurotic disorders]. / Vzgliad na zakonomernosti izmenenii molekuliarnoi organizatsii membrany i funktsional'nykh svoistv érytrotsitov pri nevroticheskikh rasstroistvakh.

Investigation into structural, metabolic, and functional conditions of red blood cells was performed in 24 patients with a neurosis (neurasthenia, disturbance of asaptation) with the aid of electrophoretic division of proteins of the erythrocyte membrane, thin-layer chromatography, fluorescent probing of membranes, evaluation of peroxidative oxidation process, scanning and transmission electron microscopy, laser diphractometry, photometry. The patients with neurotic disorders at the early period after the influence of psychogenic factors (up to 3 months) revealed disorganization of lipid and protein composition of the red cell membrane, increase in microviscosity of its lipid phase, impairment of surface architectonics and ultrastructure of red cells, decrease of a deformation ability and increase of aggregate properties of erythrocytes. The authors treat stability of erythrocytes' homeostasis under the long-term influence of psychogenic factors from a viewpoint of adaptive changes in organism under the influence of neurogenic factors.

Neurotic psychopathology and alexithymia among winter swimmers and controls--a prospective study.

Random samples of 25 voluntary Finnish winter swimmers (7 males, 18 females) and 11 controls (3 males, 8 females were followed prospectively during the winter season from October 1999 to May 2000 to (determine whether winter swimming is beneficial for mental well-being, as many of its practitioners claim. The Crown-Crisp Experimental Index (CCEI) was used for measuring free-floating anxiety, phobic anxiety, obsessionality, depression, somatic anxiety and hysteria, and the 20-item version of the Toronto Alexithymia Scale (TAS-20) for measuring alexithymia. Self-reported somatic and mental health and the reasons for and the frequency of winter-swimming were asked, too. As resealed by open questions, the winter swimmers reported positive effects of winter swimming. Several of the swimmers also told that they had started winter swimming to improve their physical and mental health. Their experience was that the swimming had relieved physical symptoms and made their mood more positive. However, we found no major differences between winter swimmers and controls in any CCEI or TAS variables. The structured questionnaires do not necessarily, however, reach subjective feelings and experiences.

Magnesium and some psychological features in two groups of pupils (magnesium and psychic features).

The aim of our study was to compare Mg levels and psychological features in two pupils groups with different conditions. It also ascertained the relationship between Mg levels and some aspects of intellectual development (attention, memory and intelligence) and personality features (psychoticism, neuroticism and extraversion). 103 pupils from an orphanage and 100 pupils from a secondary school were investigated. Serum and erythrocyte magnesium levels were determined and psychological examinations were accomplished with specific tests. The study indicated a difference between the two groups as regards magnesium level and the investigated psychological features. A direct correlation between magnesium level and neuroticism was demonstrated.

[A control study of personality characteristics and variation of plasma peptide in pilots with neurosis].

Objective. To study the relationship between personality type and variation of plasma peptides in pilots with neurosis. Method. A case-control study was used. 124 male pilots were evaluated with Eysenck's personality checklist, and then level of certain plasma peptides, such as vasoactive intestinal peptide (VIP), beta-endorphin (beta-EP) and angiotensin-II (A-II) were determined. Result. There were significant difference in personality characteristics and personality types between pilots with neuroses and the control. The contents of VIP and beta-EP in plasma showed visible difference between disease group and control. Content of beta-EP in those with inner-unstable type personality was lowest among all the various types. Conclusion. Personality characteristics were different between pilots with neurosis and controls. Levels of VIP and beta-EP in disease group were lower than those in the control. Different personality types had different levels of beta-EP in pilots with neurosis.

Neuroticism is not associated with the serotonin transporter (5-HTTLPR) polymorphism.

A deletion/insertion polymorphism in the transcriptional control region of the serotonin transporter gene (5-HTTLPR) was reported to be associated with dimensional measures of neuroticism, although subsequent replication attempts have failed. These replication attempts, however, have been dissimilar to the initial study in sample size, distribution of allelic frequency and/or assessment of neuroticism. The current study was conducted in a further attempt to replicate the initial finding using: (a) a sample that was more comparable to each of the individual samples in the initial report; and (b) identical psychometric methodology to assess neuroticism. Two hundred and twenty-five Caucasian adults were genotyped for the 5-HTTLPR polymorphism and completed the NEO Personality Inventory. Results did not replicate the association between the 5-HTTLPR polymorphism and neuroticism; individuals with the short form of this variant did not report higher NEO Neuroticism. Indeed, men with the short form reported lower Anxiety, a finding that is directionally opposite to the initial results. These findings, combined with other failures to replicate, indicate that the reproducibility of the association between the 5-HTTLPR polymorphism and neuroticism must be regarded as questionable. The contradictory findings suggest the need for a replication attempt in a large, normative sample that is stratified by ethnicity and sex.

Correlations between plasma-neuropeptides and temperament dimensions differ between suicidal patients and healthy controls.

BACKGROUND: Decreased plasma levels of plasma-neuropeptide Y (NPY) and plasma-corticotropin releasing hormone (CRH), and increased levels of plasma delta-sleep inducing peptide (DSIP) in suicide attempters with mood disorders have previously been observed. This study was performed in order to further understand the clinical relevance of these findings. METHODS: Examination of correlates between temperament dimensions (Karolinska Scales of Personality (KSP), the Eysenck Personality Questionnaire together with the IVE- impulsiveness scale (EPQI), and the Marke-Nyman Temperament (MNT)) and NPY, CRH and DSIP and serum-cortisol in the dexamethasone suppression test (DST) in 38 suicidal patients and matched controls. RESULTS: NPY correlated significantly and positively with psychasthenia, irritability, and stability and significantly and negatively with validity in patients, but significantly and negatively with muscular tension, psychasthenia, verbal aggression and irritability in controls. DSIP correlated significantly and positively with impulsiveness (EPQI) in controls. CRH correlated negatively with lie in controls. Cortisol correlated significantly and positively with validity, extraversion and verbal aggression and significantly and negatively with inhibition of aggression in controls. CONCLUSION: NPY may be related to stress tolerance. DSIP seems to be associated with impulsivity/antisocial traits. LIMITATIONS: Non-suicidal patients were not included in the examination. CLINICAL RELEVANCE: The state of depression or stress seems to influence the correlations studied.

[The modulating effects of preparations of Baikal skullcap (Scutellaria baicalensis) on erythron reactions under conditions of neurotic exposures]. / Moduliruiushchie éffekty preparatov shlemnika baikal'skogo na reaktsii éritrona v usloviiakh nevroticheskikh vozdeistvii.

Preparations of Scutellaria baicalensis, namely its dry extract and the bioflavonoid baicalin stimulate erythropoiesis depressed in deprivation of the paradoxical phase of sleep. After a conflict situation, when hemopoiesis is activated, both drugs normalize it. The modulating effect of drugs on hemopoiesis in exposure to neurotic factors is a consequence of their influence on the functional state of the cell elements of the hemopoiesis-inducing microenvironment. The capacity of the Scutellaria baicalensis drugs for reducing the effect of psychoemotional stress on the blood system is apparently related to their influence on the adrenergic structures.

[Oxygen consumption in neurotic patients]. / Potreblenie kisloroda u bol'nykh nevrozami.

29 male patients with neuroses (neurasthenia in 15 individuals, phobic neurosis in 14 persons) were observed using 22 indexes of oxygen transport and utilization including physical loading (running). Neurotic patients were differed from healthy individuals by lower both absolute and relative maximal oxygen consumption (MOC) values as well as by lower indexes of lungs ventilations, CO2 elimination, respiration frequencies and breath depth. The low maximal metabolism values, low values of energy production maximum, total running time, critical speed, low maximum lactate concentration and its slowing-down during restoration peroid, as well as less pH and BE values displacement after loading were also observed in patients. It was supposed that MOC as well energy potentials decrease may be of significant importance in neurotic disturbances development.

Psychologic symptoms before and after parathyroid surgery.

PURPOSE: To identify in an outpatient setting the type and number of psychologic symptoms of patients with primary hyperparathyroidism before and after surgery. PATIENTS AND METHODS: A convenience sample of 18 patients with primary hyperparathyroidism and a comparison sample of 20 patients with benign thyroid disease were scheduled by their primary care physician to have surgery. Assessments of psychologic symptoms, using the Symptom Checklist-90-Revised, and measurements of serum total calcium, ionized calcium, parathyroid hormone, albumin, alkaline phosphatase, urea nitrogen, creatinine, protein, and phosphate were obtained preoperatively. and at 1, 3, and 6 months postoperatively. RESULTS: The hyperparathyroid group had significantly higher (p < 0.01) levels of total and ionized serum calcium and parathyroid hormone preoperatively, with biochemical normalization 1 month postoperatively. These patients showed multidimensional psychologic symptom distress preoperatively in the areas of obsession-compulsion, interpersonal sensitivity, depression, anxiety, hostility, and psychoticism; they also had a greater number and intensity of distressful symptoms. Paranoid ideation was significantly higher in the hyperparathyroid group than in the comparison group, but it did not quite reach the clinical range. The greatest improvement in symptoms occurred by 1 month after surgery, with the hyperparathyroid group approaching the normative mean. There were no group differences before or after surgery for the areas of somatization and phobic anxiety. CONCLUSIONS: The Symptom Checklist-90-Revised is a simple, quick, and cost-effective way to quantitatively assess the psychologic symptoms of patients with primary hyperparathyroidism. We found that psychologic symptom distress is multidimensional, that symptoms had profoundly improved by 1 month after parathyroidectomy, and that somatization and anxiety did not differ between our groups.

[Morphofunctional parameters of the thyroid gland in late periods after prolonged stress in rat strains selected for nervous system excitability]. / Morfofunktsional'nye pokazateli shchitovidnoi zhelezy v otdalennye sroki posle dlitel'nogo stressirovaniia u linii krys, selektirovannykh po vozbudimosti nervnoi sistemy.

Thyroid morphology, function, and hormonal levels were studied in two rat strains with genetically determined levels of nervous system excitability immediately and in late periods after prolonged stress resulting in development of a neurosis-like state. A high resistance of the linear characteristics of thyroid morphology and function was revealed whose high functional activity was observed in the rats with a low excitability threshold. Two weeks after neurotization cessation morphofunctional status of the thyroid normalized.