Michael Deuschle

City living and urban upbringing affect neural social stress processing in humans

More than half of the world’s population now lives in cities, making the creation of a healthy urban environment a major policy priority. Cities have both health risks and benefits, but mental health is negatively affected: mood and anxiety disorders are more prevalent in city dwellers and the incidence of schizophrenia is strongly increased in people born and raised in cities. Although these findings have been widely attributed to the urban social environment, the neural processes that could mediate such associations are unknown. Here we show, using functional magnetic resonance imaging in three independent experiments, that urban upbringing and city living have dissociable impacts on social evaluative stress processing in humans. Current city living was associated with increased amygdala activity, whereas urban upbringing affected the perigenual anterior cingulate cortex, a key region for regulation of amygdala activity, negative affect and stress. These findings were regionally and behaviourally specific, as no other brain structures were affected and no urbanicity effect was seen during control experiments invoking cognitive processing without stress. Our results identify distinct neural mechanisms for an established environmental risk factor, link the urban environment for the first time to social stress processing, suggest that brain regions differ in vulnerability to this risk factor across the lifespan, and indicate that experimental interrogation of epidemiological associations is a promising strategy in social neuroscience.

Twenty-Four Hour Cortisol Release Profiles in Patients With Alzheimer’s and Parkinson’s Disease Compared to Normal Controls: Ultradian Secretory Pulsatility and Diurnal Variation

Endocrine abnormalities of the hypothalamic-pituitary-adrenal (HPA) system in patients with Alzheimers disease (AD) and Parkinsons disease (PD) have been described repeatedly. However, no data are available on the diurnal cortisol secretory pattern in these major neurodegenerative disorders. Therefore, we studied 24-h pulsatile cortisol secretion in 12 patients with AD and 12 patients with PD compared to 10 normal community- and age-matched volunteers (NV). Twenty-four hour blood sampling was performed from 1800 h to 1800 h at 15-min intervals. Cortisol half-life, number of cortisol secretory bursts/24-h, interpulse interval, mass of cortisol secreted per burst, amplitude of cortisol secretory bursts, pulsatile cortisol production rate, 24-h mean, and integral cortisol concentrations were calculated by applying deconvolution analysis. Furthermore, the relative diurnal variation and the quiescent period were determined. Patients with AD and PD were found to have significantly higher total plasma cortisol concentrations (24-h pulsatile cortisol production rate: AD + 56%; PD + 52%/24-h integrated cortisol: AD + 37%; PD + 29%) compared to NV. This sustained hypercortisolism is due to a higher mass of cortisol secreted per burst (AD + 62%; PD + 79%), but not to increased cortisol half-life or secretory pulse frequency or amplitude. Despite these similarities between AD and PD patients, relative diurnal variation of cortisol secretion was significantly decreased in patients with PD (-22%), whereas the pattern of secretory curves was not different between NV and AD patients. This observation was indirectly supported by a reduction of the quiescent period in patients with PD (-74 min) compared to the NV and AD group. Based on these results and recently published animal data, we hypothesize that decreased expression of hippocampal mineralocorticoid receptors (MR) may account for the flattened diurnal cortisol secretory curve observed in PD patients, whereas the intact diurnal profile in AD patients may be due to a relative increase in MR compensating for the hippocampal neuronal loss commonly occurring in this disorder.

With aging in humans the activity of the hypothalamus-pituitary-adrenal system increases and its diurnal amplitude flattens.

There is compelling evidence for feedback disturbances in the hypothalamus-pituitary-adrenal system associated with human aging as assessed by challenge tests. However, reports about age-related changes in human basal activity are ambiguous and to date little is known about changes in the pulsatile features of the HPA system. To investigate these changes we studied twenty-two healthy male and eleven healthy female subjects ranging from 23 to 85 and 24 to 81 years respectively. 24-hour blood sampling with 30 minute sampling intervals was performed. From 18.00 to 24.00 hours blood was sampled every 10 minutes for analysis of pulsatile features of HPA activity. Statistical analysis revealed that age in particular had major effects upon basal HPA-system activity: there was a significant age-associated increase in minimal (p < 0.0001) and mean (p < 0.02) cortisol plasma concentrations, but no alteration in pulsatile features. We found no age-cortisol correlation during daytime, but were able to demonstrate a strong impact of age upon cortisol plasma levels from 20.00 to 1.30 hours. The diurnal amplitude of cortisol (p < 0.005) and ACTH (p < 0.006), relative to the 24-hour mean of the hormones, showed an age-associated decline. Additionally, the evening cortisol quiescent period (p < 0.01) was shortened in the elderly, suggesting increasingly impaired circadian function in aging. Our results suggest an increased basal activity and a flattened diurnal amplitude of the HPA system in the elderly.

Hypercortisolemic Depression Is Associated With Increased Intra-abdominal Fat

Objective Similar to patients with a metabolic syndrome, patients with major depression are at increased risk of developing cardiovascular disorders. Interestingly, both disorders share a specific endocrine syndrome that promotes the accumulation of visceral fat, which again is considered a marker of increased cardiovascular morbidity and mortality. Methods Intra-abdominal fat was measured in 22 postmenopausal depressed women and 23 age-matched healthy women by computer tomography at the level of lumbar vertebrae 1 (L1) and 4 (L4). Saliva was taken in patients and control subjects at 08:00 hours over a period of 7 drug-free days for the measurement of free cortisol. In patients only we performed an oral glucose tolerance test. Results Compared with control subjects, depressed patients with elevated free cortisol concentrations showed similar visceral fat depots at L1 (113.0 ± 41.6 vs. 94.3 ± 53.2 cm2). Hypercortisolemic depressed patients also showed greater fat depots in this area (74.5 ± 55.5 cm2, p = .04) than the normocortisolemic patients. However, a comparison of all patients with control subjects revealed no difference in fat accumulation at either L1 or L4. Finally, glucose concentrations during the glucose tolerance test were higher in hypercortisolemic than in normocortisolemic patients, whereas their insulin levels showed only a tendency toward being increased. Conclusions Hypercortisolemic depressed patients suffer from resistance to insulin and increased visceral fat. The fact that hypercortisolemia reverses depression-related fat loss, particularly in the visceral area, might partially explain why major depression can be considered a risk factor for cardiovascular disorders.

Testosterone, gonadotropin, and cortisol secretion in male patients with major depression.

OBJECTIVE Previous studies of sex hormone concentrations in depression yielded inconsistent results. However, the activation of the hypothalamic-pituitary-adrenal system seen in depression may negatively affect gonadal function at every level of regulation. The objective of this study was to explore whether major depressive episodes are indeed associated with an alteration of gonadal function. METHODS Testosterone, pulsatile LH secretion, FSH, and cortisol were assessed using frequent sampling during a 24-hour period in 15 male inpatients with major depression of moderate to high severity and in 22 healthy comparison subjects (age range 22-85 years). RESULTS An analysis of covariance model showed that after adjustment for age only, daytime testosterone (p < .01), nighttime testosterone (p < .05), and 24-hour mean testosterone secretion (p < .01) were significantly lower in the depressed male inpatients. There was also a trend for a decreased LH pulse frequency in the depressed patients (p < .08). CONCLUSIONS Gonadal function may be disturbed in men with a depressive episode of moderate to high severity.

Testosterone, androstenedione and dihydrotestosterone concentrations are elevated in female patients with major depression

Hyperactivity of the HPA-system in major depression is reflected by an increased secretion of adrenal hormones especially cortisol and dehydroepiandrosterone (DHEA). In women for whom androgenicity is associated with cardiovascular disorders the dominant source of androstenedione and testosterone secretion are the adrenal glands. To date, there is only sparse information about the regulation of androstenedione, testosterone and dihydrotestosterone (DHT) concentrations in women with severe major depression.Therefore, 11 pre- and postmenopausal, severely depressed, hypercortisolemic women (Hamilton Depression Scale, 31.3+/-5.9; age, 28-77 yrs; mean, 48. 1+/-18.1 yrs) and 11 age-matched healthy female controls (age, 24-81 yrs; mean, 47.9+/-21.5 yrs) underwent a 24 hour (h) blood sampling starting at 0800 h with 30-minute sampling intervals. By applying multivariate analysis of covariance with age as covariate, androstenedione, testosterone and DHT plasma levels at 0900 h show a trend for elevated concentrations in depressed women compared to controls (F(1,19)=2.7; P=0.057). Univariate F tests reveal a significant difference between the groups for androstenedione (4. 19+/-1.571 vs 2.584+/-1.257 nmol/l; P<0.05) testosterone (1.110+/-0. 278 vs 0.833+/-0.347 nmol/l; P<0.05) and DHT (0.656+/-0.207 vs 0. 483+/-0.242 nmol/l; P<0.05). Mean ACTH (16.4+/-10.4 vs 10.4+/-2.4 pmol/l; P=0.89), LH (13.5+/-11.8 vs 8.9+/-9.2 IU/l; P=0.12), FSH (35. 2+/-33.1 vs 31.3+/-35.7 IU/l; P=0.67) and estradiol (135.4+/-157.4 vs 82.2+/-85.1 pmol/l; P=0.20) plasma levels did not differ between patients and controls. Further, there was a trend towards an age related decline in testosterone secretion in healthy controls (r=-0. 24; P=0.08) which did not occur in depressed patients (r=0.17; P=0. 96), while the calculated ratio of DHEA to testosterone was similar in both groups (0.2+/-0.14 vs 0.13+/-0.7; P=0.21, unpaired t-test). In conclusion, androstenedione, testosterone and DHT concentrations all were increased in hypercortisolemic women with severe major depression. These findings are best explained as a consequence of an overstimulation of the adrenal glands through pituitary and hypothalamic sites of the HPA-system.

Effects of Major Depression, Aging and Gender upon Calculated Diurnal Free Plasma Cortisol Concentrations: a Re-Evaluation Study

Depression, aging and female gender are associated with increased diurnal concentrations of total plasma cortisol. For the physical effects of hypercortisolemia, however, it is generally assumed that free rather than total plasma cortisol concentrations are of importance. Herein, we report a mathematical approach to determine free plasma cortisol concentrations on the basis of total cortisol, corticosteroid binding-globulin (CBG) and albumin plasma concentrations. This approach was used to re-evaluate two sets of data in order to estimate the effect of depression as well as the effect of aging and gender upon free plasma cortisol concentrations. Comparing male depressed patients with healthy controls, we found 24-hour free cortisol minima (MIN: 4.1 +/- 1.8 vs. 1.6 +/- 1.1 nmol/l, p < 0.0001), mean (MEAN: 25.5 +/- 6.7 vs. 10.4 +/- 2.7 nmol/l, p < 0.0001) and maximal (MAX: 85.3 +/- 23.3 vs. 45.2 +/- 15. 8 nmol/l, p < 0.0001) concentrations to be significantly increased in depressed patients. In general, the impact of depression upon total plasma cortisol were not only maintained, but stronger regarding free plasma cortisol. Also, age was associated with free plasma cortisol MIN (F1,30= 10.8, p < 0.003) and free plasma cortisol MEAN (F1,30 = 8.9, p < 0.006). All effects of age upon total plasma cortisol were generally also found in free plasma cortisol, though with less impact. No effect of gender upon any of the given free plasma cortisol outcome variables was found. Taken together, our re-evaluation clearly shows not only depression but also aging to be associated with increases in free plasma cortisol concentrations. This finding is in line with the observation that in both conditions medical problems triggered and/or maintained by glucocorticoids (e.g. osteoporosis) are frequently seen.

Pituitary-adrenal and sympathetic nervous system responses to stress in women remitted from recurrent major depression.

Objective: To better understand the changes in hypothalamus-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS) function after remission of depression. We characterized these systems at baseline and in response to a psychosocial stressor in a cohort of women remitted from recurrent major depression as well as in never-depressed healthy female controls. Methods: Baseline HPA function was measured via saliva cortisol sampling at 8 AM and 4 PM over 7 days as well as quantification of urinary overnight cortisol secretion. The HPA system response to a psychosocial stressor was assessed by measuring serum cortisol and adrenocorticotropic hormone (ACTH) levels and SNS reactivity by determining serum epinephrine (E) and norepinephrine (NE) concentrations as well as autonomic nervous system changes by analysis of heart rate variability (HRV). The stressor included a speech task, mental arithmetic, and a cognitive challenge. Results: In all, we studied 22 women remitted from recurrent major depression (age = 51.0 ± 1.7 years) and 20 healthy controls (age = 54.2 ± 1.6 years). Morning saliva cortisol concentrations were lower in remitted patients, paralleled by lower serum cortisol concentrations before stress testing. This group also displayed a blunted cortisol and ACTH response to the stressor, as compared with healthy controls. No between-group differences in HRV parameters were observed. Conclusion: In this group of women remitted from recurrent major depressive disorder, we found evidence of HPA system hypoactivity, both in the basal state and in response to a psychosocial stressor. ACTH = adrenocorticotropic hormone; E = epinephrine; HAM-D = Hamilton Depression Scale; HPA = hypothalamus-pituitary-adrenal; HF = high frequency; HRV = heart rate variability; HR = heart rate; LF = low frequency; NE = norepinephrine; rm-ANOVA = repeated-measures analysis of variance; SNS = sympathetic nervous system; VAS = visual analogous scale.

Increased platelet aggregability in major depression

There is compelling evidence that depression constitutes an independent risk factor for cardiovascular morbidity and mortality. As exaggerated platelet reactivity is associated with an increased risk of intra-arterial thrombus formation, we studied platelet aggregability in patients with major depression both before and after 5 weeks of anti-depressant therapy as well as in healthy control subjects. Twenty-two depressed patients and 24 healthy control subjects participated in the study. Washed and rediluted platelets were stimulated with the agonists collagen and thrombin in three concentration steps. Depression was associated with a higher aggregability after stimulation with thrombin in the intermediate concentration and with collagen at the low concentration, with ceiling effects for the other concentrations. After 5 weeks of anti-depressant therapy, aggregability was somewhat less exaggerated, although this effect did not reach statistical significance. We thus conclude that major depression is associated with increased platelet aggregability, which seems to persist even under a marked improvement in depressive symptomatology. This effect may contribute to the increased cardiovascular morbidity in depressed patients.

Lipid metabolism and insulin resistance in depressed patients: significance of weight, hypercortisolism, and antidepressant treatment

Abstract: Major depression increases cardiovascular risk despite lower cholesterol levels. Little is known about effects of antidepressants on metabolic risk factors. We studied lipoprotein composition, insulin sensitivity (quantitative insulin sensitivity check index), and saliva cortisol in 78 depressed patients before and after 35 days of amitriptyline or paroxetin treatment. Data were analyzed by principal component factor analyses and analysis of variance (ANOVA). At baseline, quantitative insulin sensitivity check index was inversely correlated with cortisol (r = −0.46; P = 0.005) in normal weight patients, with body mass index in overweight patients (r = −0.50; P < 0.001). In overweight patients, hypercortisolemia correlated inversely with total and low density lipoprotein cholesterol (eg, cortisol at 4:00 PM and low density lipoprotein cholesterol: r = −0.49, P = 0.002). After treatment, quantitative insulin sensitivity check index was unchanged. Triglycerides increased in responders to amitriptyline only (P < 0.05). Parameters of cholesterol metabolism improved slightly without differences between treatment groups (eg, high density lipoprotein: pre 43.5 ± 12.0; post 47.6 ± 13.0 mg/dL; P = 0.01; low density lipoprotein triglycerides, a measure of low density lipoprotein atherogenicity: pre 458 ± 120; post 415 ± 130 mg/g; P < 0,01). The inverse correlation of cortisol and cholesterol, at least in the obese subgroup, proposes a mechanism for the known association of depression with low cholesterol. As determinants of plasma lipids in major depression, we identified body mass index, insulin sensitivity, and cortisol. Although uncontrolled, our data suggest that treatment of depression exerts a mainly beneficial effect on lipid regulation.Abbreviations: AMI = amitriptyline, BMI = body mass index, DSM IV = Diagnostic and Statistical Manual, IVth revision, HAMD = hamilton depression scale,HDL= high density lipoprotein, hypothalamus-pituitaryadrenal axis, LDL = low density lipoprotein, PAR = paroxetin, PPARa = peroxisome proliferation activator receptor a, QUICKI = quantitative insulin sensitivity check index, SSRI = selective serotonine reuptake inhibitor, TCA = tricyclic antidepressant, VLDL = very low density lipoprotein.