Neuropsychological functioning in health and mood disorder: Modulation by glucocorticoids and their receptors

Association of polymorphic variants in GEMIN genes with the risk of depression in a Polish population

Background

The role of miRNA in depression is widely described by many researchers. miRNA is a final product of many genes involved in its formation (maturation). One of the final steps in the formation of miRNAs is the formation of the RISC complex, called the RNA-induced silencing complex, which includes, among others, GEMIN proteins. Single-nucleotide polymorphisms (SNPs) may lead to disturbance of miRNA biogenesis and function. The objective of our research was to assess the relationship between the appearance of depression and single nucleotide polymorphisms in the GEMIN3 (rs197388) and GEMIN4 (rs7813; rs3744741) genes. Our research provides new knowledge on the genetic factors that influence the risk of depression. They can be used as an element of diagnostics helpful in identifying people at increased risk, as well as indicating people not at risk of depression.

Methods

A total of 218 participants were examined, including individuals with depressive disorders (n = 102; study group) and healthy people (n = 116, control group). All the patients in the study group and the people in the control group were non-related native Caucasian Poles from central Poland. Blood was collected from study and control groups in order to assess the SNPs of GEMIN genes.

Results

An analysis of the results obtained showed that in patient population, the risk of depression is almost doubled by polymorphic variants of the genes: rs197388/GEMIN3 genotype A/A in the recessive model and rs3744741/GEMIN4 genotype T/T, codominant and recessive model. The dual role of rs7813/GEMIN4 is noteworthy, where the G/A genotype in the codominant and over dominant model protects against depression.

Brain structure in autoimmune Addison's disease

Long-term disturbances in cortisol levels might affect brain structure in individuals with autoimmune Addison's disease (AAD). This study investigated gray and white matter brain structure in a cohort of young adults with AAD. T1- and diffusion-weighted images were acquired for 52 individuals with AAD and 70 healthy controls, aged 19-43 years, using magnetic resonance imaging. Groups were compared on cortical thickness, surface area, cortical gray matter volume, subcortical volume (FreeSurfer), and white matter microstructure (FSL tract-based spatial statistics). Individuals with AAD had 4.3% smaller total brain volume. Correcting for head size, we did not find any regional structural differences, apart from reduced volume of the right superior parietal cortex in males with AAD. Within the patient group, a higher glucocorticoid (GC) replacement dose was associated with smaller total brain volume and smaller volume of the left lingual gyrus, left rostral anterior cingulate cortex, and right supramarginal gyrus. With the exception of smaller total brain volume and potential sensitivity of the parietal cortex to GC disturbances in men, brain structure seems relatively unaffected in young adults with AAD. However, the association between GC replacement dose and reduced brain volume may be reason for concern and requires follow-up study.

The Importance of Endoplasmic Reticulum Stress as a Novel Antidepressant Drug Target and Its Potential Impact on CNS Disorders

Many central nervous system (CNS) diseases, including major depressive disorder (MDD), are underpinned by the unfolded protein response (UPR) activated under endoplasmic reticulum (ER) stress. New, more efficient, therapeutic options for MDD are needed to avoid adverse effects and drug resistance. Therefore, the aim of the work was to determine whether UPR signalling pathway activation in astrocytes may serve as a novel target for antidepressant drugs. Among the tested antidepressants (escitalopram, amitriptyline, S-ketamine and R-ketamine), only S-ketamine, and to a lesser extent R-ketamine, induced the expression of most ER stress-responsive genes in astrocytes. Furthermore, cell viability and apoptosis measuring assays showed that (R-)S-ketamine did not affect cell survival under ER stress. Under normal conditions, S-ketamine played the key role in increasing the release of brain-derived neurotrophic factor (BDNF), indicating that the drug has a complex mechanism of action in astrocytes, which may contribute to its therapeutic effects. Our findings are the first to shed light on the relationship between old astrocyte specifically induced substance (OASIS) stabilized by ER stress and (R-)S-ketamine; however, the possible involvement of OASIS in the mechanism of therapeutic ketamine action requires further study.

Cellular Response to Unfolded Proteins in Depression

Despite many scientific studies on depression, there is no clear conception explaining the causes and mechanisms of depression development. Research conducted in recent years has shown that there is a strong relationship between depression and the endoplasmic reticulum (ER) stress. In order to restore ER homeostasis, the adaptive unfolded protein response (UPR) mechanism is activated. Research suggests that ER stress response pathways are continuously activated in patients with major depressive disorders (MDD). Therefore, it seems that the recommended drugs should reduce ER stress. A search is currently underway for drugs that will be both effective in reducing ER stress and relieving symptoms of depression.

Neuropsychology of Bipolar Disorder

Bipolar disorder is associated with significant dysfunction in a broad range of neuropsychological domains and processes. Deficits have been reported to occur in symptomatic states (depression, [hypo]mania) as well as in remission (euthymia), having consequences for psychological well-being and social and occupational functioning. The profile and magnitude of neuropsychological deficits in bipolar disorder have been explored in a number of systematic reviews and meta-analyses. After discussing these briefly, this chapter will focus on examining the clinical and demographic factors that influence and modify the pattern and magnitude of deficits, as well as reviewing methods of assessment and analysis approaches which may improve our understanding of these problems.

The association between adversity and hair cortisol levels in humans: A meta-analysis

Adverse life events are associated with a constellation of negative health outcomes. Theory and research suggest that the hypothalamic-pituitary-adrenal (HPA) axis acts as one mechanism connecting adverse experiences with negative health outcomes. However, this relation is complicated by the potential for adversity to be associated with both hyperactivity and hypoactivity of the HPA axis, as assessed in both animal and human studies. Over the past decade, methodological advances have enabled the sampling of cortisol stored in hair, which provides a marker of HPA axis activity over a several-month period. The present meta-analysis included 28 studies to assess the strength and direction of the relation between adverse experiences and hair cortisol levels. Analyses were conducted using multilevel modeling (MLM) to quantify the magnitude of effects and mixture modeling to identify distinct subgroups of studies. Results of MLM analyses indicated that the overall effect size was small but significant d = 0.213, 95% CI [0.034, 0.397]. There was also significant between-study variance (τ = 0.155, 95% CI [0.065, 0.367]). Mixture modeling to identify distinct classes of studies based on effect size and direction resulted in a 2-class model: The first class included four studies with an overall negative and moderate effect size (d = -0.478, 95% CI [-0.639, -0.318]), and the second class included the remaining 24 studies with an overall positive and significant, albeit small, effect size (d = 0.141, 95% CI [0.084, 0.199]). Moderator analyses indicated that the strength and direction of the association between adversity and hair cortisol were moderated by features of the adversity exposure (e.g., type of adversity, timing of adversity), characteristics of the samples (e.g., clinical status, racial distribution), and features of the publication (e.g., publication type, geographic region of study). The findings refine our understanding of the long-term impact of adversity on dysregulation of the HPA axis, particularly as reflected in hair cortisol measures.

Prenatal immune activation in mice blocks the effects of environmental enrichment on exploratory behavior and microglia density

Adverse environmental factors including prenatal maternal infection are capable of inducing long-lasting behavioral and neural alterations which can enhance the risk to develop schizophrenia. It is so far not clear whether supportive postnatal environments are able to modify such prenatally-induced alterations. In rodent models, environmental enrichment influences behavior and cognition, for instance by affecting endocrinologic, immunologic, and neuroplastic parameters. The current study was designed to elucidate the influence of postnatal environmental enrichment on schizophrenia-like behavioral alterations induced by prenatal polyI:C immune stimulation at gestational day 9 in mice. Adult offspring were tested for amphetamine-induced locomotion, social interaction, and problem-solving behavior as well as expression of dopamine D1 and D2 receptors and associated molecules, microglia density and adult neurogenesis. Prenatal polyI:C treatment resulted in increased dopamine sensitivity and dopamine D2 receptor expression in adult offspring which was not reversed by environmental enrichment. Prenatal immune activation prevented the effects of environmental enrichment which increased exploratory behavior and microglia density in NaCl treated mice. Problem-solving behavior as well as the number of immature neurons was affected by neither prenatal immune stimulation nor postnatal environmental enrichment. The behavioral and neural alterations that persist into adulthood could not generally be modified by environmental enrichment. This might be due to early neurodevelopmental disturbances which could not be rescued or compensated for at a later developmental stage.

Fischer 344 and Lewis Rat Strains as a Model of Genetic Vulnerability to Drug Addiction

Today it is well acknowledged that both nature and nurture play important roles in the genesis of psychopathologies, including drug addiction. Increasing evidence suggests that genetic factors contribute for at least 40–60% of the variation in liability to drug dependence. Human genetic studies suggest that multiple genes of small effect, rather than single genes, contribute to the genesis of behavioral psychopathologies. Therefore, the use of inbred rat strains might provide a valuable tool to identify differences, linked to genotype, important in liability to addiction and related disorders. In this regard, Lewis and Fischer 344 inbred rats have been proposed as a model of genetic vulnerability to drug addiction, given their innate differences in sensitivity to the reinforcing and rewarding effects of drugs of abuse, as well their different responsiveness to stressful stimuli. This review will provide evidence in support of this model for the study of the genetic influence on addiction vulnerability, with particular emphasis on differences in mesolimbic dopamine (DA) transmission, rewarding and emotional function. It will be highlighted that Lewis and Fischer 344 rats differ not only in several indices of DA transmission and adaptive changes following repeated drug exposure, but also in hypothalamic-pituitary-adrenal (HPA) axis responsiveness, influencing not only the ability of the individual to cope with stressful events, but also interfering with rewarding and motivational processes, given the influence of corticosteroids on dopamine neuron functionality. Further differences between the two strains, as impulsivity or anxiousness, might contribute to their different proneness to addiction, and likely these features might be linked to their different DA neurotransmission plasticity. Although differences in other neurotransmitter systems might deserve further investigation, results from the reviewed studies might open new vistas in understanding aberrant deviations in reward and motivational functions.

Cognitive functioning and cortisol profiles in first episode major depression

Major Depressive Disorder (MDD) is often associated with high levels of stress and disturbances in the Hypothalamic Pituitary Adrenal (HPA) system, yielding high levels of cortisol, in addition to cognitive dysfunction. Previous studies have shown a relationship between cortisol profile and cognitive functioning in recurrent MDD in general. More specifically, the association between hypercortisolism and cognitive functioning, such as memory and Executive Functioning (EF), and also more recently cortisol suppression has been explored. However, no studies have investigated these relationships in patients diagnosed with first episode MDD. The aim of the present study was to examine the relationship between cortisol levels before and after the Dexamethasone suppression test (DST) and cognitive function in first episode MDD patients. Twenty-one patients meeting the DSM-IV criteria for a first episode of MDD diagnosis were included in the study. The control group was matched for age, gender and education level. Cortisol was measured in saliva collected with Salivette sampling devices. Saliva samples were collected 4 times during a 24 hours period over two consecutive days: at awakening, after 45 minutes, after 7 hours and at 11 pm. Dexamethasone (1.0 mg) was given orally on Day 1 at 11 pm. The neuropsychological test battery consisted of standardized tests measuring executive functioning (EF) and memory functioning. Cortisol levels did not differ significantly between patients and controls on Day 1, except for the last sample before Dexamethasone administration, where the control group showed higher levels. Both groups showed suppression after Dexamethasone. On Day 2 there was a significant difference between groups at the third sample, showing a significantly lower level in the control group, suggesting that the controls have a more effective suppression profile than the patients. There were no significant correlations between cortisol levels before or after Dexamethasone and cognitive measures. The results indicate impairment on HPA-axis functioning in first episode MDD patients, with less suppression functioning compared to healthy controls, but no relationship between cortisol profile and cognitive functioning in EF or Memory.

Neuropsychology of Neuroendocrine Dysregulation after Traumatic Brain Injury

Endocrine dysfunction is a common effect of traumatic brain injury (TBI). In addition to affecting the regulation of important body functions, the disruption of endocrine physiology can significantly impair mental functions, such as attention, memory, executive function, and mood. This mini-review focuses on alterations in mental functioning that are associated with neuroendocrine disturbances in adults who suffered TBI. It summarizes the contribution of hormones to the regulation of mental functions, the consequences of TBI on mental health and neuroendocrine homeostasis, and the effects of hormone substitution on mental dysfunction caused by TBI. The available empirical evidence suggests that comprehensive assessment of mental functions should be standard in TBI subjects presenting with hormone deficiency and that hormone replacement therapy should be accompanied by pre- and post-assessments.

The effects of two different doses of hydrocortisone on cognition in patients with secondary adrenal insufficiency--results from a randomized controlled trial

CONTEXT

A wide variety in hydrocortisone (HC) substitution dose-regimens are considered physiological for patients with secondary adrenal insufficiency (SAI). However, it is likely that cognition is negatively influenced by higher cortisol exposure to the brain.

OBJECTIVE

To examine the effects of a high physiological HC dose in comparison to a low physiological HC dose on cognition.

DESIGN AND SETTING

This study was a randomized double blind cross-over study at the University Medical Center Groningen. This study is registered with ClinicalTrials.gov, number NCT01546922.

PATIENTS

Forty-seven patients (29 males, 18 females; mean [SD] age, 51 [14] years, range 19-73) with SAI participated.

INTERVENTION(S)

Patients randomly received first a low dose of HC (0.2-0.3 mg/kg body weight/day) during 10 weeks followed by a high dose (0.4-0.6 mg/kg body weight/day) for another 10 weeks, or vice versa. HC substitution was given in three divided doses with the highest dose in the morning.

MAIN OUTCOME MEASURE(S)

Cognitive performance (memory, attention, executive functioning and social cognition) of patients was measured at baseline and after each treatment period using a battery of 12 standardized cognitive tests.

RESULTS

The higher dose of HC resulted in significantly higher systemic cortisol exposure for example measured at 1h after first dose ingestion (mean [SD], low dose: 653 [281] nmol/L; high dose: 930 [148] nmol/L; P<0.001). No differences in cognitive performance were found between the two dose regimens.

CONCLUSIONS

No negative influence on memory, attention, executive functioning and social cognition was observed after 10 weeks of treatment with a higher physiological dose of HC in patients with SAI when compared to a lower dose.

Summary cortisol reactivity indicators: Interrelations and meaning

Research on the hypothalamic pituitary adrenal (HPA) axis has involved a proliferation of cortisol indices. We surveyed recently published HPA-related articles and identified 15 such indices. We sought to clarify their biometric properties, specifically, how they interrelate and what they mean, because such information is rarely offered in the articles themselves. In the present article, the primary samples consist of community mothers and their infants (N = 297), who participated in two challenges, the Toy Frustration Paradigm and the Strange Situation Procedure. We sought to cross-validate findings from each of these samples against the other, and also against a clinically depressed sample (N = 48) and a sample of healthy older adults (N = 51) who participated in the Trier Social Stress Test. Cortisol was collected from all participants once before and twice after the challenges. These heterogenous samples were chosen to obtain the greatest possible range in cortisol levels and stress response regulation. Using these data, we computed the 15 summary cortisol indices identified in our literature survey. We assessed inter-relations amongst indices and determined their underlying dimensions via principal component analysis (PCA). The PCAs consistently extracted two components, accounting for 79%–93% of the variance. These components represent “total cortisol production” and “change in cortisol levels.” The components were highly congruent across challenge, time, and sample. High variable loadings and explained factor variance suggest that all indices represent their underlying dimensions very well. Thus the abundance of summary cortisol indices currently represented in the literature appears superfluous.

Cognitive functioning and cortisol suppression in recurrent major depression

Major Depressive Disorder (MDD) is often associated with high levels of stress and disturbances in the hypothalamic-pituitary-adrenal (HPA) system, yielding high levels of cortisol in addition to cognitive dysfunction. The aim of the present study was to examine the relation between cortisol levels after the dexamethasone suppression test and cognitive function in recurrent unipolar MDD patients. Twenty-four patients meeting the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.) criteria for a recurrent MDD diagnosis were included in the study. The control group was matched for age, sex, and education level. Cortisol was measured in saliva collected with Salivette sampling devices. Saliva samples were collected four times during a 24-hr period over two consecutive days: at awakening, after 45 min, after 7 hr, and at 11:00 p.m. One milligram of dexamethasone was given on Day 1 at 11:00 p.m. The neuropsychological test battery consisted of standardized tests measuring cognitive functioning within verbal and visual memory, as well as executive functioning. Cortisol levels did not differ between patients and controls on Day 1. Cortisol levels in patients were higher than in controls at awakening on Day 2 (D2S1), after dexamethasone administration the previous evening. All significant correlations between cognitive measures and cortisol at D2S1 were negative, indicating that low suppression after intake of dexamethasone is related to poor cognitive functioning. Significant relations were found in three of the cognitive tests measuring verbal memory, semantic fluency, and inhibition. The present findings indicate that dysregulation of the HPA-axis is related to poor verbal memory functioning. There was no firm evidence that abnormal cortisol levels were associated with inhibition difficulties.

Depressive symptoms as predictor of dementia versus continuous cognitive decline: a 3-year prospective study

Previous research including meta-analytic efforts supports the assumption that depression is able to predict dementia. The mechanisms of this association still remain to be revealed. Some possible explanations as, for example, the glucocorticoid cascade hypothesis assumes that there are underlying changes at the cortical level that drive the association. Therefore, gradual levels of depressive symptoms may also predict gradual change (decline) in cognitive performance. However, testing both of these predictions (depressive symptoms lead to dementia, and depressive symptoms lead to cognitive decline, respectively) with the same data has to our knowledge not been done in the previous literature. A sample of 562 participants aged 65 or older was examined four times over a period of 3 years. Study participants completed established measures of depression and cognitive functioning. Results based on Cox regression analysis showed that depressive symptoms were not able to predict the conversion to dementia during the following 3 years. Additionally, structural equation models as well as latent change score models did not support the assumption that depressive symptoms predict cognitive decline, measured as a continuous variable. We discuss several possibilities to explain these findings including the potential and possible limits of the glucocorticoid cascade hypothesis.

Neurobiological markers of familial risk for depression

Major depression is associated with a wide range of neurobiological disturbances, including anomalies in the structure and function of cortical and subcortical gray matter and dysregulation of the HPA axis. In this chapter, we review research demonstrating that many of these abnormalities are also present in never-depressed offspring of adults with recurrent depression and discuss how such findings might reflect dysfunctional neuroregulatory systems that precede the onset of this disorder. We also briefly discuss candidate genes and environmental factors that have been posited to be directly involved in the transmission of neural and HPA-axis abnormalities from depressed parents to their offspring, and we review how, by obtaining a better understanding of the neurobiological markers of depression risk, we can facilitate the development of targeted strategies for the prevention and treatment of major depression.

Single nucleotide polymorphisms of NR3C1 gene and recurrent depressive disorder in population of Poland

Depressive disorder is a disease characterized by disturbances in the hypothalamo-pituitary-adrenal axis. Abnormalities include the increased level of glucocorticoids (GC) and changes in sensitivity to these hormones. The changes are related to glucocorticoid receptors gene (NR3C1) variants. The NR3C1 gene is suggested to be a candidate gene affecting depressive disorder risk and management. The aim of this study was to investigate polymorphisms within the NR3C1 gene and their role in the susceptibility to recurrent depressive disorder (rDD). 181 depressive patients and 149 healthy ethnically matched controls were included in the study. Single nucleotide polymorphisms were assessed using polymerase chain reaction/restriction fragment length polymorphism method. Statistical significance between rDD patients and controls was observed for the allele and genotype frequencies at three loci: BclI, N363S, and ER22/23EK. The presence of C allele, CC, and GC genotype of BclI polymorphism, G allele and GA genotype for N363S and ER22/23EK variants respectively were associated with increased rDD risk. Two haplotypes indicated higher susceptibility for rDD, while haplotype GAG played a protective role with OR(dis) 0.29 [95 % confidence interval (CI) = 0.13-0.64]. Data generated from this study support the earlier results that genetic variants of the NR3C1 gene are associated with rDD and suggest further consideration on the possible involvement of these variants in etiology of the disease.

Racial/ethnic differences in the longitudinal progression of co-occurring negative affect and cigarette use: from adolescence to young adulthood

AIMS

This study examined the longitudinal progression of the co-occurrence of cigarette use and negative affect among the general population of U.S. adolescents and young adults and between racial/ethnic groups.

METHODS

Data for this study consisted of Waves 4, 6, and 8 of the NLSY97 longitudinal study containing a nationally representative sample of U.S. adolescents and young adults. A total of 7979 adolescents (Mean age at Wave 4=17.98, SD=1.44, 49% female) were included in the analyses. To investigate the co-morbidity between negative affect and cigarette use, a latent factor of negative affect and single indicator of cigarette consumption were examined at each wave. A three wave Bivariate Autoregressive Cross-Lagged Effect Model was estimated to test the conjoint trajectory of negative affect and smoking.

RESULTS

For all racial/ethnic groups prior negative affect status influenced future negative affect between waves and prior negative affect was positively related to increases in smoking in subsequent waves. The longitudinal trajectory of negative affect for the three racial/ethnic groups was the same, but racial/ethnic group differences were observed in the strength of the longitudinal relationship between previous and future cigarette use. Specifically, the following racial/ethnic differences were observed, even after controlling for the effect of SES; White young adults were found to exhibit the strongest association between cigarette use in the first two waves, followed by Hispanic individuals and lastly by African Americans. In the last two waves, African American young adults were found to have the strongest association between cigarette use at the latter two waves, followed by White individuals.

CONCLUSIONS

Both negative affect and cigarette consumption influence each other during the transition between late adolescence and young adulthood but the magnitude of the associations between cigarettes use across waves differed between racial/ethnic groups. Implications for prevention and treatment programs include considering both cigarette use and negative affect as two factors that jointly impact each other and that should be targeted simultaneously.

Central glucocorticoid receptor-mediated effects of the antidepressant, citalopram, in humans: a study using EEG and cognitive testing

Our previous work in cellular and animal models has shown that antidepressants activate glucocorticoid receptor (GR) translocation, induce GR down-regulation, and decrease GR-mediated effects in the presence of GR agonists. However, whether these effects can be extrapolated to the human brain is still unclear. In this study, the effects of four days of treatment with the antidepressant, citalopram (20 mg/day), or placebo, were assessed in a double-blind, placebo-controlled, cross-over study. Central GR-mediated effects were examined by the effects of a single dose of cortisol (30 mg, orally) on two measures known to be sensitive to glucocorticoid administration: EEG alpha power and working memory function. Twenty healthy male subjects aged between 18 and 33 years participated to the study. The results suggest that GR activation by antidepressants, and the subsequent decrease in GR-mediated effects in the presence of GR agonists, indeed occurs in the human brain. Specifically, pre-treatment with citalopram decreased the well-known ability of cortisol to increase EEG alpha power and to impair working memory: cortisol-induced increase in EEG alpha power was (anteriorly) +15 to +20% (p=0.01) after placebo and +5 to +8% (p>0.5) after citalopram; and cortisol-induced increase in working memory errors was (at level 12, on average) 2.50 vs. 4.55 (p<0.05) after placebo and 4.10 vs. 3.35 (p>0.05) after citalopram. No effects were detected on alerting. These results are consistent with the notion that citalopram treatment activates GR translocation and inhibits the functional consequences of the subsequent cortisol administration. Our study further emphasizes the importance of the GR as a target for antidepressant action in humans.

The relationship of current depressive symptoms and past depression with cognitive impairment and instrumental activities of daily living in an elderly population: the Sydney Memory and Ageing Study

Depressive symptoms are common in the elderly and they have been associated with cognitive and functional impairment. However, relatively less is known about the relationship of a lifetime history of depression to cognitive impairment and functional status. The aim of this cross-sectional study was to assess whether current depressive symptoms and past depression are associated with cognitive or functional impairment in a community-based sample representative of east Sydney, Australia. We also examined whether there was an interaction between current and past depression in their effects on cognitive performance. Eight hundred non-demented aged participants received a neuropsychological assessment, a past psychiatric history interview and the 15-item Geriatric Depression Scale. The Bayer-Activities of Daily Living scale was completed by an informant to determine functional ability. Clinically relevant depressive symptoms were present in 6.1% of the sample and 16.6% reported a history of depression. Participants with current depression had significantly higher levels of psychological distress and anxiety, and lower life satisfaction and performed worse on memory and executive function compared to participants without current depression. After controlling for anxiety the effect on executive function was no longer significant while the effect on memory remained significant. A history of depression was associated with worse executive function, higher levels of psychological distress and anxiety, and lower life satisfaction. After controlling for psychological distress the effect of past depression on executive function was no longer significant. There were no significant interactions between current and past depression in their effects on cognitive performance. There were no differences between participants with or without current depression and with or without past depression on functional abilities. These results support the view that current and past depressive episodes are associated with poorer cognitive performance but not with functional abilities.

Racial discrimination, mood disorders, and cardiovascular disease among black americans

PURPOSE

To examine associations between racial discrimination, mood disorders, and cardiovascular disease (CVD) among Black Americans.

METHODS

Weighted logistic regression analyses were performed on a nationally representative sample of Black Americans (n = 5022) in the National Survey of American Life (NSAL; 2001-2003). Racial discrimination and CVD were assessed via self-report. Mood disorder was measured with the World Health Organization Composite International Diagnostic Interview.

RESULTS

Model-adjusted risk ratios (RRs) revealed that participants with a history of mood disorder had greater risk of CVD (RR, 1.28; 95% confidence interval (CI), 1.12-1.45). This relationship was found specifically among those younger than 50 years of age (RR, 1.56; 95% CI, 1.27-1.91). There was a significant interaction between racial discrimination and mood disorder in predicting CVD in the total (F = 2.86, 3 df, p = .047) and younger sample (F = 2.98, 3 df, p = .047). Participants with a history of mood disorder who reported high levels of racial discrimination had the greatest risk of CVD.

CONCLUSIONS

The association between racial discrimination and CVD is moderated by history of mood disorder. Future studies may examine pathways through which racial discrimination and mood disorders impact CVD risk among Black Americans.

Significance of serum glucocorticoid and chelatable zinc in depression and cognition in zinc deficiency

Dietary zinc deficiency elicits neuropsychological symptoms and cognitive dysfunction. To pursue the mechanisms of these symptoms, in the present study, the relationship among serum glucocorticoid, chelatable zinc in the synaptic cleft and brain function based on behavior was examined in young rats fed a zinc-deficient diet for 4 weeks. Serum glucocorticoid level was significantly increased in zinc-deficient rats. However, the induction of in vivo dentate gyrus LTP and object recognition memory were not affected in zinc-deficient rats. Chelatable zinc levels were decreased in the stratum lucidum of the hippocampal CA3, but not in the molecular layer of the dentate gyrus. It is reported that dentate gyrus LTP and object recognition memory are affected in clioquinol (30mg/kg)-administered rats, in which chelatable zinc is significantly decreased in the molecular layer of the dentate gyrus. Thus, the significant decrease in chelatable zinc in the molecular layer of the dentate gyrus may be required for object recognition memory deficit in zinc deficiency. On the other hand, the time of grooming in the open-field test was decreased in zinc-deficient rats. Immobility time in the forced swim test was increased in zinc-deficient rats, but not in clioquinol-administered rats, in which chelatable zinc was more markedly decreased than in zinc-deficient rats, suggesting that the lack of chelatable zinc does not increase depression-like behavior. These results suggest that the chronic increase in serum glucocorticoid level is involved in the increase in depression-like behavior rather than the decrease in chelatable zinc after 4-week zinc deficiency.

Changes in neuropsychological functioning over 10 years following adolescent substance abuse treatment

Previously, Anderson, Ramo, Cummins, and Brown (2010) described six distinct patterns of alcohol and other drug (AOD) use during the decade following adolescents' treatment for alcohol and other substance use disorders (A/SUD). This time period represents a phase of significant neurodevelopment, and the influence of substance use on the brain is a concern. In the present study, we examined patterns of neuropsychological function over these 10 years in relation to the AOD trajectories identified for youth as they transition into their twenties. Participants were part of a longitudinal research project following adolescents with and without A/SUD who received neuropsychological examinations at baseline and up to 7 times thereafter spanning 10 years (N = 213; 46% female at baseline). Neuropsychological trajectories were significantly related to substance involvement patterns over time on measures of verbal learning and memory (ps = .011 to <.0001), visuospatial memory (p = .0002), and verbal attention/working memory (p = .020), with heavier use patterns generally followed by poorer cognition. Heavy use of alcohol alone was independently associated with poorer verbal memory over time. Furthermore, substance withdrawal symptoms during each follow-up time point were related to poorer verbal learning and memory scores (ps < .05), whereas substance abuse/dependence diagnostic criteria were not related to neuropsychological performance levels. These findings suggest that AOD use during adolescence and young adulthood may primarily influence performance that relies on later maturing brain structures, although further research is needed. Higher levels of AOD withdrawal symptoms may signify greater neuropsychological impairment, reflecting potential neurotoxic effects of AOD use.

Caloric restriction experience reprograms stress and orexigenic pathways and promotes binge eating

Long-term weight management by dieting has a high failure rate. Pharmacological targets have focused on appetite reduction, although less is understood as to the potential contributions of the stress state during dieting in long-term behavioral modification. In a mouse model of moderate caloric restriction in which a 10-15% weight loss similar to human dieting is produced, we examined physiological and behavioral stress measures. After 3 weeks of restriction, mice showed significant increases in immobile time in a tail suspension test and stress-induced corticosterone levels. Increased stress was associated with brain region-specific alterations of corticotropin-releasing factor expression and promoter methylation, changes that were not normalized with refeeding. Similar outcomes were produced by high-fat diet withdrawal, an additional component of human dieting. In examination of long-term behavioral consequences, previously restricted mice showed a significant increase in binge eating of a palatable high-fat food during stress exposure. Orexigenic hormones, melanin-concentrating hormone (MCH) and orexin, were significantly elevated in response to the high-fat diet only in previously restricted mice. Furthermore, administration of the MCH receptor-1 antagonist GSK-856464 [4-(4-ethyl-5-methylsulfanyl-1,2,4-triazol-3-yl)pyridine] significantly reduced total caloric intake in these mice during high-fat access. These results reveal reprogramming of key central pathways involved in regulating stress responsivity and orexigenic drives by moderate caloric restriction experience. In humans, such changes would be expected to reduce treatment success by promoting behaviors resulting in weight regain, and suggest that management of stress during dieting may be beneficial in long-term maintenance.

Volume of the adrenal and pituitary glands in depression

Numerous studies have shown that the hypothalamic-pituitary-adrenal (HPA) axis is hyperactive in some depressed patients. It is unclear whether such hyperactivity results in changed volumes of the adrenal glands, pituitary gland and hypothalamus. We systematically reviewed all controlled studies on the adrenal or pituitary glands or hypothalamus volume in unipolar depressive disorder published in PubMed 1966 to December 2009. We identified three studies that investigated the volume of the adrenal glands and eight studies that examined the volume of the pituitary gland, but no studies on hypothalamus were found. Two out of three studies found a statistically significant increase in adrenal volume in patients compared to controls. Four out of eight studies found a statistically significant increase in pituitary volume in patients compared to controls. Different methodological problems were identified such as small population samples, different subtypes of depression and insufficient matching of patients and controls. Due to large heterogeneity of study designs and data, it was futile to make a meta-analysis. It is concluded that it remains unclear whether hyperactivity of the HPA axis results in enlarged adrenal and pituitary glands and it is suggested that prospective studies should be conducted with scanning during successive depressive episodes and periods of remission.

The transcriptional response to chronic stress and glucocorticoid receptor blockade in the hippocampal dentate gyrus

The dentate gyrus (DG) of the hippocampus plays a crucial role in learning and memory. This subregion is unique in its ability to generate new neurons throughout life and integrate these new neurons into the hippocampal circuitry. Neurogenesis has further been implicated in hippocampal plasticity and depression. Exposure to chronic stress affects DG function and morphology and suppresses neurogenesis and long-term potentiation (LTP) with consequences for cognition. Previous studies demonstrated that glucocorticoid receptor (GR) blockade by a brief treatment with the GR antagonist mifepristone (RU486) rapidly reverses the stress and glucocorticoid effects on neurogenesis. The molecular pathways underlying both the stress-induced effects and the RU486 effects on the DG are, however, largely unknown. The aim of this study was therefore (1) to investigate by microarray analysis which genes and pathways in the DG are sensitive to chronic stress and (2) to investigate to what extent blockade of GR can normalize these stress-induced effects on DG gene expression. Chronic stress exposure affected the expression of 90 genes in the DG (P < 0.01), with an overrepresentation of genes involved in brain development and morphogenesis and synaptic transmission. RU486 treatment of stressed animals affected expression of 107 genes; however, mostly different genes than those responding to stress. Interestingly, we found CREBBP to be normalized by RU486 treatment to levels observed in control animals, suggesting that CREB-signaling may play a central role in mediating the chronic stress effects on neurogenesis, LTP and calcium currents. The identified genetic pathways provide insight into the stress-induced adaptive plasticity of the hippocampal DG that is so central in learning and memory and will direct future studies on the functional outcome and modulation of these stress effects.

HPA axis alterations in mental disorders: impact on memory and its relevance for therapeutic interventions

Dysfunctions in hypothalamic-pituitary-adrenal (HPA) axis have been reported for several mental disorders that are also often characterized by memory disturbances. It is now well established that glucocorticoids influence cognitive processes by enhancing memory consolidation and impairing memory retrieval. There is further evidence for an association between HPA axis related disturbances and memory function in mental disorders. The present selective review provides a brief overview of HPA axis dysfunction and its impact on memory function in major depressive disorder, posttraumatic stress disorder, and borderline personality disorder. Furthermore, the relevance of these findings for therapeutic intervention is discussed.

Childhood separation experience predicts HPA axis hormonal responses in late adulthood: a natural experiment of World War II

BACKGROUND

Animal models have linked early maternal separation with lifelong changes in hypothalamic-pituitary-adrenocortical (HPA) axis activity. Although this is paralleled in human studies, this is often in the context of other life adversities, for example, divorce or adoption, and it is not known whether early separation in the absence of these factors has long term effects on the HPA axis.

AIMS

The Finnish experience in World War II created a natural experiment to test whether separation from a father serving in the armed forces or from both parents due to war evacuation are associated with alterations in HPA axis response to psychosocial stress in late adulthood.

METHOD

282 subjects (M=63.5 years, SD=2.5), of whom 85 were non-separated, 129 were separated from their father, and 68 were separated from both their caregivers during WWII, were enlisted to participate in a Trier Social Stress Test (TSST), during which we measured salivary cortisol and, for 215 individuals, plasma cortisol and ACTH concentrations. We used mixed models to study whether parental separation is associated with salivary and plasma cortisol or plasma ACTH reactivity, and linear regressions to analyse differences in the baseline, or incremental area under the cortisol or ACTH curves.

RESULTS

Participants separated from their father did not differ significantly from non-separated participants. However, those separated from both parents had higher average salivary cortisol and plasma ACTH concentrations across all time points compared to the non-separated group. They also had higher salivary cortisol reactivity to the TSST. Separated women had higher baselines in plasma cortisol and ACTH, whereas men had higher reactivity in response to stress during the TSST. Participants who had experienced the separation in early childhood were more affected than children separated during infancy or school age.

CONCLUSIONS

Separation from parents during childhood may alter an individual's stress physiology much later in adult life.

Neuroactive steroids: an update of their roles in central and peripheral nervous system

After five editions, the congress on "Steroids and Nervous System" held in Torino, Italy, represents an important international event for researchers involved in this field aimed to recapitulate mechanisms, physiological and pharmacological effects of neuroactive steroids. The present review introduces manuscripts collected in this supplement issue which are based on new interesting findings such as the influence of sex steroids on cannabinoid-regulated biology, the role of steroids in pain, the importance of co-regulators in steroidal mechanisms and the understanding of new non classical mechanism, the emerging role of vitamin D as a neuroactive steroid and the pathogenetic mechanisms mediated by glucocorticoid receptors. Finally, we have integrated these aspects with an update on some of the several and important observations recently published on this hot topic.