The cortisol awakening response and memory performance in older men and women.

The activity and regulation of the hypothalamus-pituitary-adrenal axis has been related to cognitive decline during aging. This study investigated whether the cortisol awakening response (CAR) is related to memory performance among older adults. The sample was composed of 88 participants (44 men and 44 women) from 55 to 77 years old. The memory assessment consisted of two tests measuring declarative memory (a paragraph recall test and a word list learning test) and two tests measuring working memory (a spatial span test and a spatial working memory test). Among those participants who showed the CAR on two consecutive days, we found that a greater CAR was related to poorer declarative memory performance in both men and women, and to better working memory performance only in men. The results of our study suggest that the relationship between CAR and memory performance is negative in men and women when memory performance is largely dependent on hippocampal functioning (i.e. declarative memory), and positive, but only in men, when memory performance is largely dependent on prefrontal cortex functioning (i.e. working memory).

Social defeat and isolation induce clear signs of a depression-like state, but modest cardiac alterations in wild-type rats.

Adverse social environments play a relevant role in the onset and progression of mood disorders. On the other hand, depression is an independent risk factor for cardiovascular morbidity. This study was aimed at (i) corroborating the validity of a rat model of depression based on a negative social episode followed by social isolation and (ii) verifying its impact on cardiac function and structure. Pair housed, wild-type Groningen rats (Rattus norvegicus) were implanted with radiotransmitters for ECG, temperature and activity recordings. They were either exposed to a social defeat episode followed by 4-week isolation or left undisturbed with their female partners. The social challenge induced a series of biological changes that are commonly taken as markers of depression in rats, including decreased body weight gain and reduced preference for sucrose consumption, functional and structural changes of the hypothalamic-pituitary-adrenocortical axis, increased anxiety in the elevated plus maze test. The cardiovascular alterations consisted in (i) transitory heart rate circadian rhythm alterations, (ii) lack of habituation of cardiac autonomic responsivity (tachycardia and vagal withdrawal) to an acute stressor, and (iii) moderate hypertrophy affecting the right ventricle of the heart. These results indicate that a depression-like state induced via this model of social challenge was associated with a few modest cardiovascular changes. Further studies are required to confirm the validity of this rat model of depression as a valid preclinical approach to the comprehension of the biological substrates underlying depression-cardiovascular comorbidity.

The neuroendocrinology of childhood trauma in personality disorder.

BACKGROUND: Childhood trauma has been associated with elevated central corticotropin releasing hormone (CRH) drive in adults meeting general DSM-IV criteria for personality disorder. It is not clear how this may be related to pituitary or adrenal responsiveness in personality disorder. It was hypothesized that high levels of childhood trauma would be associated with blunted cortisol and adrenocorticotropin releasing hormone (ACTH) response to the combined dexamethasone(DEX)/CRH test in adults meeting general DSM-IV criteria for personality disorder. METHOD: 24 healthy, medication free adults with personality disorder (N=16) and a group of healthy controls (N=8) underwent semi-structured diagnostic interviews and completed the Childhood Trauma Questionnaire (CTQ). Across two separate study sessions separated by at least a week, cerebrospinal fluid (CSF) was sampled by lumbar puncture for measurement of CRH concentration (N=17), and peripheral blood cortisol and ACTH levels were measured after challenge with DEX/CRH (N=24). RESULTS: As hypothesized, high CTQ score was associated with a blunted cortisol and ACTH response to DEX/CRH challenge. Indices of cortisol and ACTH response (peak level and area under the curve (AUC)) to DEX/CRH were in turn significantly negatively correlated with CSF CRH concentration. CONCLUSION: Childhood trauma in adults with personality disorder is associated with blunted cortisol and ACTH secretion following DEX/CRH challenge. These effects are independent of depression or posttraumatic stress disorder. Previous work would suggest that blunted pituitary-adrenal response is related to elevated central CRH drive. Corroborating this, CSF CRH levels were significantly and negatively correlated with peak level and AUC of both cortisol and ACTH.

The cortisol awakening response in amyotrophic lateral sclerosis is blunted and correlates with clinical status and depressive mood.

Considerable evidence indicates that amyotrophic lateral sclerosis (ALS), a progressive neurodegenerative disease of the motor system, has an enormous impact on the patient's emotional and physical well-being. As previous findings indicated that particularly the rise in cortisol levels immediately after awakening, i.e., the cortisol awakening response (CAR), is associated with indices of physical and emotional well-being, we compared the CAR of 29 admitted ALS patients with that of 12 age-matched caregiver controls. Saliva samples for cortisol measurement were collected immediately, 15, 30 and 45 min after awakening. The severity of ALS progression was quantified using the ALS functional rating scale (ALSFRS) and manual muscle test (MMT). Depressive mood status in ALS patients was determined with the Beck Depression Inventory (BDI) and Hamilton Depression Rating Scale (HDRS). Salivary cortisol levels of ALS patients did not differ from those of caregiver controls at awakening, 15 min or 45 min after awakening, but were significantly lower at 30 min after awakening. Area under the curve analysis confirmed that the CAR was significantly smaller in ALS patients than in caregiver controls. A smaller CAR in ALS patients was significantly correlated to poorer clinical status, as assessed with both the ALSFRS and MMT rating instruments. Further, a smaller CAR significantly correlated with a more severe depressive mood status. No correlations were observed between total cortisol output during the first 45 min post-awakening and clinical or depressive status. In conclusion, our findings indicate that ALS patients show a blunted CAR, correlated with disease and depression severity.

Chronic overexpression of corticotropin-releasing factor from the central amygdala produces HPA axis hyperactivity and behavioral anxiety associated with gene-expression changes in the hippocampus and paraventricular nucleus of the hypothalamus.

Environmental stress has been demonstrated to increase susceptibility for mood and anxiety disorders, and hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis, the primary endocrine response to stress, is often observed in these patients. HPA axis activation is initiated by corticotropin-releasing factor (CRF) from the hypothalamus, leading to the hypothesis that hypothalamic CRF overexpression contributes to HPA axis hyperactivity in psychiatric patients. In addition, elevated CRF in cerebrospinal fluid is observed in mood and anxiety disorder patients, suggesting that CRF is also being overproduced from extrahypothalamic sources such as the central amygdala (CeA) and overactivity of the amygdala in neuroimaging studies is a consistent finding in anxiety and depression patients. Due to the importance of CRF and the amygdala in the etiology of stress-sensitive psychiatric disorders, the present study sought to further dissect the impact of CRF overexpression (OE) in the amygdala on downstream behavioral, endocrine, and gene-expression changes typically associated with chronic stress. To test the hypothesis that elevated CRF output from the amygdala would reproduce HPA axis hyperactivity and behavioral symptoms of chronic stress, we developed a lentiviral vector in which 3.0kb of the CRF promoter drives overexpression of CRF (LVCRFp3.0CRF). In adult male rats, Experiment-1 examined behavioral consequences of chronic CRF overexpression from the amygdala; the dexamethasone (Dex)/CRF test was used to measure HPA axis reactivity. Experiment-2 focused on HPA axis disruptions; the dexamethasone-suppression and CRF-stimulation tests as well as the Dex/CRF test were used. In both experiments, expression of HPA-axis related transcripts were assessed.

Polymorphisms within the metabotropic glutamate receptor 1 gene are associated with depression phenotypes.

OBJECTIVES: Glutamate has been implicated in the pathophysiology and treatment of mood disorders possibly by affecting the regulation of the hypothalamus-pituitary-adrenocortical (HPA) axis. Growing evidence suggests an important role of the metabotropic glutamate receptor 1 (mGlu1) in depression-related phenotypes. To test whether these findings can also be supported by human genetics data, we explored polymorphisms within the metabotropic glutamate receptor 1 gene (GRM1) for their association with unipolar depression (UPD) as well as with biological phenotypes of this disorder. METHODS: We first tested the association of 43 tag-SNPs covering the GRM1 locus with UPD in 350 patients and 370 matched controls. We then investigated the effects of the associated SNPs on hippocampal glutamate levels estimated using ¹H-MR-spectroscopy (¹H-MRS) and on endocrine measures from the combined dexamethasone-suppression/CRH stimulation (dex/CRH) test. RESULTS: Within the GRM1 locus, 22 SNPs showed nominally significant association with UPD, of which 6 withstood corrections for multiple testing (rs2268666 with best allelic p=7.0×10⁻5). Supportive evidence for an association with UPD was gained from a second independent sample with 904 patients and 1012 controls. Furthermore, patients homozygous for the non-risk genotypes showed reduced hippocampal glutamate levels as measured by ¹H-MRS, a more pronounced normalization of HPA-axis hyperactivity as well as a better antidepressant treatment outcome. CONCLUSIONS: These results suggest that the combination of genetic and biological markers may allow to subgroup patients into etiopathogenetically more relevant subcategories which could guide clinicians in their antidepressant treatment choices.

Adulthood trauma and HPA-axis functioning in healthy subjects and PTSD patients: a meta-analysis.

BACKGROUND: Hypothalamic-pituitary-adrenal (HPA)-axis dysregulation has inconsistently been associated with posttraumatic stress disorder (PTSD). Yet, trauma exposure rather than PTSD may be responsible for HPA-axis dysregulation. In two meta-analyses, we assessed the association of adulthood trauma exposure and HPA-axis functioning in healthy subjects with and without PTSD. METHOD: A literature search in Pubmed and PsychInfo, using keywords and MeSH terms such as cortisol, emotional trauma, and PTSD, was performed. Only studies that included mentally healthy trauma-exposed (TE) individuals as well as non-exposed (NE) healthy individuals and/or PTSD patients (PTSD) were selected. This resulted in 1511 studies of which ultimately, 37 studies (21 TE versus NE and 34 TE versus PTSD, N=2468) were included. Methodological quality of all studies was assessed according to specific quality criteria. Pooled effect sizes (Hedges's g) on cortisol levels were compared. For all analyses, random effect models were used. RESULTS: Cortisol levels were neither significantly different between TE versus NE subjects (-0.029; 95%CI: -0.145; 0.088) nor between TE subjects versus PTSD patients (0.175; 95%CI: -0.012; -0.362). Subgroup analyses showed an increased cortisol suppression after the low dose dexamethasone suppression test (DST) in TE versus NE subjects (-0.509; 95%CI: -0.871; -0.148). This meta-analysis was limited by the fact that lifetime psychiatric illness and childhood trauma were not an exclusion criterion in all 37 studies. CONCLUSION: Neither adulthood trauma exposure nor PTSD were associated with differences in HPA-axis functioning, although adulthood trauma may augment cortisol suppression after the DST. More evidence on other dynamic tests of HPA-axis functioning in PTSD and adulthood trauma exposure is needed.

Symptom-specific associations between low cortisol responses and functional somatic symptoms: the TRAILS study.

BACKGROUND: Functional somatic symptoms (FSS), like chronic pain and overtiredness, are often assumed to be stress-related. Altered levels of the stress hormone cortisol could explain the association between stress and somatic complaints. We hypothesized that low cortisol levels after awakening and low cortisol levels during stress are differentially associated with specific FSS. METHODS: This study is performed in a subsample of TRAILS (Tracking Adolescents' Individual Lives Survey) consisting of 715 adolescents (mean age: 16.1 years, SD=0.6, 51.3% girls). Adolescents' cortisol levels after awakening and during a social stress task were assessed. The area under the curve with respect to the ground (AUCg) and the area under the curve above the baseline (AUCab) were calculated for these cortisol levels. FSS were measured using the Youth Self-Report and pain questions. Based upon a factor analysis, FSS were divided into two clusters, one consisting of headache and gastrointestinal symptoms and the other consisting of overtiredness, dizziness and musculoskeletal pain. RESULTS: Regression analyses revealed that the cluster of headache and gastrointestinal symptoms was associated with a low AUCg of cortisol levels during stress (ß=-.09, p=.03) and the cluster of overtiredness, dizziness and musculoskeletal pain with a low AUCg of cortisol levels after awakening (ß=-.15, p=.008). All these analyses were adjusted for the potential confounders smoking, physical activity level, depression, corticosteroid use, oral contraceptive use, gender, body mass index and, if applicable, awakening time. CONCLUSION: Two clusters of FSS are differentially associated with the stress hormone cortisol.

Neuroendocrine response to CRF stimulation in veterans with and without PTSD in consideration of war zone era.

BACKGROUND: Alterations in hypothalamic-pituitary-adrenal (HPA) axis activity have been observed in Gulf War veterans with posttraumatic stress disorder (PTSD) which differ from those observed in other veteran groups, raising the possibility that there is a unique neuroendocrine profile in this group of veterans. This study seeks to further characterize the effects of PTSD, military cohort (Vietnam, 1991 Gulf War, Operations Enduring Freedom/Iraqi Freedom (OEF/OIF)), and their interaction on the neuroendocrine response to synthetic corticotrophin-releasing factor (CRF) stimulation. METHODS: 51 male veterans were studied consisting of 21 from the Vietnam era, 16 from the Gulf War era, and 14 from the OEF/OIF era. 16 of these veterans were deployed to a war zone and had chronic PTSD (PTSD+), 25 were deployed to a war zone and did not have chronic PTSD (PTSD-), and 10 were not deployed to a war zone and did not have PTSD (non-exposed). The participants underwent the CRF stimulation test in the afternoon (approximately 2:00 p.m.), which measures the integrity and sensitivity of the pituitary-adrenal axis. Plasma cortisol and adrenocorticotropic hormone (ACTH) were measured at baseline and at intervals over a 2h period following intravenous administration of 1 µg/kg of ovine CRF (o-CRF, max 100 µg). In a small subset of participants, dehydroepiandrosterone (DHEA) and cortisol binding globulin (CBG) were also assessed. RESULTS: There was a significant group by era interaction in the response of ACTH to CRF, in addition to a main effect of group (PTSD+, PTSD-, non-exposed). The interaction reflected that group differences were only evident in the Gulf War cohort; among Gulf War era veterans, the PTSD+ group had higher elevations in ACTH levels following CRF than the PTSD- group and the non-exposed group. Additionally, the peak change in ACTH was associated with a self-reported environmental exposure (pyridostigmine bromide ingestion) which has been found to be linked to the excess morbidity found in Gulf War veterans. Self-reported childhood trauma was greater in veterans of the Gulf War than Vietnam or OEF/OIF, but did not account for the observed differences. There was a significant effect of group on the cortisol response to CRF, reflecting greater responsivity in both of the deployed groups (PTSD+ and PTSD-) compared to the non-exposed group which could be accounted for by baseline differences in cortisol levels; unlike the ACTH response, the cortisol response did not differ by era. There were no effects of group, era, or their interaction on the DHEA and CBG response to CRF. CONCLUSIONS: A uniform pattern of PTSD-related alterations in the response to intravenous CRF was not found. Rather, PTSD-related alterations were found only in veterans of the 1991 Gulf War, and were characterized by an enhanced pituitary response to CRF which may reflect increased sensitivity of pituitary corticotrophs or CRF hyposecretion. Together with previous neuroendocrine findings, the data suggest the HPA axis is dysregulated in Gulf War veterans in unique ways which may reflect the long-term effects of environmental exposures in addition to disease effects. Further work is needed to characterize these effects and their impact on long-term psychological and medical outcomes.