High levels of cortisol among adolescent offspring of parents with bipolar disorder: a pilot study

Putative Risk Biomarkers of Bipolar Disorder in At-risk Youth

Bipolar disorder is a highly heritable and functionally impairing disease. The recognition and intervention of BD especially that characterized by early onset remains challenging. Risk biomarkers for predicting BD transition among at-risk youth may improve disease prognosis. We reviewed the more recent clinical studies to find possible pre-diagnostic biomarkers in youth at familial or (and) clinical risk of BD. Here we found that putative biomarkers for predicting conversion to BD include findings from multiple sample sources based on different hypotheses. Putative risk biomarkers shown by perspective studies are higher bipolar polygenetic risk scores, epigenetic alterations, elevated immune parameters, front-limbic system deficits, and brain circuit dysfunction associated with emotion and reward processing. Future studies need to enhance machine learning integration, make clinical detection methods more objective, and improve the quality of cohort studies.

Dim light melatonin patterns in unaffected offspring of parents with bipolar disorder: A case-control high-risk study

BACKGROUND

Circadian dysregulation has long been thought to be a key component in the pathophysiology of bipolar disorder (BD). However, it remains unclear whether this dysregulation constitutes a risk factor, manifestation, or consequence of BD. This study aimed to compare dim light melatonin secretion patterns between unaffected offspring of parents with BD (OBD) and offspring of control parents (OCP).

METHODS

This case-control study included unaffected OBD (mean age 14.0 years; male 50.0 %) and age- and sex-matched OCP (mean age 13.0 years; male: 43.5 %). Seventeen saliva samples were collected in dim light conditions. Dim light melatonin onset (DLMO), phase angles, and area under the curve (AUC) were calculated.

RESULTS

185 saliva samples from 12 OBD (n = 12) and 741 from OCP (n = 46) were collected. Unaffected OBD had a significant lower nocturnal melatonin level (14.8 ± 4.6 vs. 20.3 ± 11.7 pg/mL) and a smaller melatonin AUC within two hours after DLMO (35.5 ± 11.3 vs. 44.6 ± 18.1 pg/mL) but a significant larger phase angle between DLMO and sleep onset (2.2 ± 1.0 vs. 1.4 ± 1.2 h) than OCP. There was no significant between-group difference in DLMO. The graphic illustrations showed a considerably flattened melatonin secretion in unaffected OBD.

LIMITATIONS

The main limitations include lack of 24-h dim melatonin secretion measurement, large age range of participants, and small sample size.

CONCLUSIONS

These findings suggest that unaffected OBD already presented with circadian rhythm dysregulations. Future investigations are needed to clarify the role of abnormal melatonin secretion in the onset of BD.

Basal and reactive cortisol: A systematic literature review of offspring of parents with depressive and bipolar disorders

One of the most consistent biological findings in the study of affective disorders is that those with depression commonly show abnormal cortisol response, which suggests dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. Children of parents with mood disorders offer the opportunity to explore the biological pathways that may confer risk for psychopathology. This review explores basal and reactive cortisol in the offspring of parents who are currently depressed or have had a history of a depressive or bipolar disorder. Using PRISMA guidelines, search terms yielded 2002 manuscripts. After screening, 87 of these manuscripts were included. Results from the literature suggest that while the degree and direction of dysregulation varies, offspring of a parent with depression tend to show elevations in both basal (particularly morning and evening) and reactive (tentatively for social stressors) cortisol levels. There were few studies focused on offspring of parents with bipolar disorder. This review also discusses implications and recommendations for future research regarding the HPA axis in the intergenerational transmission of depressive disorders.

Cortisol as a Biomarker of Mental Disorder Severity

Cortisol—the most important steroid hormone with a significant effect on body metabolism—strongly affects peripheral tissues and the central nervous system. Fluctuations in cortisol secretion often accompany psychiatric disorders, and normalization of its levels correlates with improvement in the patient’s health. This indicates that cortisol may be useful as a biological marker that can help determine the likelihood of mental illness, its impending onset, and the severity of symptoms, which is especially important in the face of the increasing prevalence of mental disorders, including those associated with social isolation and anxiety during the COVID-19 pandemic. This publication reviews recent reports on cortisol levels in healthy participants and shows the current state of knowledge on changes in the levels of this hormone in people at risk for depression, bipolar disorder, and psychosis. It shows how people with psychiatric disorders react to stressful situations and how the applied therapies affect cortisol secretion. The influence of antidepressants and antipsychotics on cortisol levels in healthy people and those with mental disorders is also described. Finally, it reviews publications on the patterns of cortisol secretion in patients in remission.

Inflammatory signaling mechanisms in bipolar disorder

Bipolar disorder is a decidedly heterogeneous and multifactorial disease, with a high individual and societal burden. While not all patients display overt markers of elevated inflammation, significant evidence suggests that aberrant immune signaling contributes to all stages of the disease, and likely explains the elevated rates of comorbid inflammatory illnesses seen in this population. While individual systems have been intensely studied and targeted, a relative paucity of attention has been given to the interconnecting role of inflammatory signals therein. This review presents an updated overview of some of the most prominent pathophysiologic mechanisms in bipolar disorder, from mitochondrial, endoplasmic reticular, and calcium homeostasis, to purinergic, kynurenic, and hormonal/neurotransmitter signaling, showing inflammation to act as a powerful nexus between these systems. Several areas with a high degree of mechanistic convergence within this paradigm are highlighted to present promising future targets for therapeutic development and screening.

Intracellular Signaling Cascades in Bipolar Disorder

Bipolar spectrum disorders carry a significant public health burden. Disproportionately high rates of suicide, incarceration, and comorbid medical conditions necessitate an extraordinary focus on understanding the intricacies of this disease. Elucidating granular, intracellular details seems to be a necessary preamble to advancing promising therapeutic opportunities. In this chapter, we review a wide range of intracellular mechanisms including mitochondrial energetics, calcium signaling, neuroinflammation, the microbiome, neurotransmitter metabolism, glycogen synthase kinase 3-beta (GSK3β), protein kinase C (PKC) and diacylglycerol (DAG), and neurotrophins (especially BDNF), as well as the glutamatergic, dopaminergic, purinergic, and neurohormonal systems. Owing to the relative lack of understanding and effective therapeutic options compared to the rest of the spectrum, special attention is paid in the chapter to the latest developments in bipolar depression. Likewise, from a therapeutic standpoint, special attention should be paid to the pervasive mechanistic actions of lithium as a means of amalgamating numerous, disparate cascades into a digestible cognitive topology.

Cortisol Awakening Response, Self-Reported Affect and Exam Performance in Female Students

The purpose of the study was to find whether there were differences in cortisol awakening response (CAR) between a neutral day and an exam day in a group of female students and to explore possible relationships between CAR, self-reported affect, and exam performance. A group of 25 female students took samples of their saliva using Salivettes at the moment of waking and after 30 min. They then described their affect using the PANAS scale. Measures were taken twice: three days before an examination and on the day of the examination. The level of free cortisol in saliva samples was determined using enzyme immunoassay. The integrated volume of cortisol (CARauc) was significantly higher on the day of the exam than on the neutral day. There were also significant differences in affect, with negative higher and positive lower on the exam day, but correlations between cortisol measures and self-reported affect were low and not significant. A negative relationship between integrated volume of cortisol (CARauc) and exam performance was also found. Anticipated exam stress caused a significant increase in CAR in female study participants when compared to a neutral day, but only in the case of integrated volume of cortisol over the waking period (CARauc). The negative relationship between this measure and exam performance can be explained by attributing CARauc to negative expectations concerning the anticipated exam.

Parenting practices in middle childhood mediate the relation between growing up with a parent having bipolar disorder and offspring psychopathology from childhood into early adulthood

The offspring of parents with bipolar disorder (OBD) are at high risk for developing mental disorders. In addition to genetic factors, environmental risk is purported to be associated with these negative outcomes. However, few studies have examined this relation. Using concurrent and longitudinal data, we examined if support, structure, and control provided by parents in middle childhood mediated the relation between having a parent with or without bipolar disorder, and offspring mental health. The sample included 145 offspring (77 OBD, 68 controls) aged 4 to 14 years and their parents. Parent and teacher ratings of child behavior were collected, and diagnostic assessments were conducted in offspring 12 years later (n = 101). Bootstrapping analyses showed that low levels of structure mediated the relation between having a parent with bipolar disorder and elevated internalizing and externalizing difficulties during middle childhood. For the longitudinal outcomes, parental control emerged as the strongest mediator of the relation between parents’ bipolar disorder and offspring psychopathology. Suboptimal childrearing may have different immediate and enduring consequences on mental health outcomes in the OBD. Parental structure has robust effects on emotional and behavioral problems in middle childhood, while levels of control promote psychological adjustment in the OBD as they mature.

Integrated transcriptome and methylome analysis in youth at high risk for bipolar disorder: a preliminary analysis

First-degree relatives of patients with bipolar disorder (BD), particularly their offspring, have a higher risk of developing BD and other mental illnesses than the general population. However, the biological mechanisms underlying this increased risk are still unknown, particularly because most of the studies so far have been conducted in chronically ill adults and not in unaffected youth at high risk. In this preliminary study we analyzed genome-wide expression and methylation levels in peripheral blood mononuclear cells from children and adolescents from three matched groups: BD patients, unaffected offspring of bipolar parents (high risk) and controls (low risk). By integrating gene expression and DNA methylation and comparing the lists of differentially expressed genes and differentially methylated probes between groups, we were able to identify 43 risk genes that discriminate patients and high-risk youth from controls. Pathway analysis showed an enrichment of the glucocorticoid receptor (GR) pathway with the genes MED1, HSPA1L, GTF2A1 and TAF15, which might underlie the previously reported role of stress response in the risk for BD in vulnerable populations. Cell-based assays indicate a GR hyporesponsiveness in cells from adult BD patients compared to controls and suggest that these GR-related genes can be modulated by DNA methylation, which poses the theoretical possibility of manipulating their expression as a means to counteract the familial risk presented by those subjects. Although preliminary, our results suggest the utility of peripheral measures in the identification of biomarkers of risk in high-risk populations and further emphasize the potential role of stress and DNA methylation in the risk for BD in youth.

Sleep and circadian alterations in people at risk for bipolar disorder: A systematic review

BACKGROUND

Sleep and circadian abnormalities have been mostly demonstrated in bipolar patients. However, it is not clear whether these alterations are present in population at high risk for bipolar disorder (BD), indicating a possible risk factor for this condition.

OBJECTIVE

This systematic review aims to define current evidence about sleep and rhythm alterations in people at risk for BD and to evaluate sleep and circadian disorders as risk factor for BD.

METHODS

The systematic review included all articles about the topic until February 2016. Two researchers performed an electronic search of PubMed and Cochrane Library. Keywords used were 'sleep' or 'rhythm' or 'circadian' AND 'bipolar disorder' or 'mania' or 'bipolar depression' AND 'high-risk' or 'risk'.

RESULTS

Thirty articles were analyzed (7451 participants at risk for BD). Sleep disturbances are frequent in studies using both subjective measures and actigraphy. High-risk individuals reported irregularity of sleep/wake times, poor sleep and circadian rhythm disruption. Poor sleep quality, nighttime awakenings, and inadequate sleep are possible predictive factors for BD. A unique study suggested that irregular rhythms increase risk of conversion. People at risk for BD showed high cortisol levels in different times of day. Studies about anatomopathology, melatonin levels, inflammatory cytokines and oxidative stress were not identified. The most important limitations were differences in sleep and rhythm measures, heterogeneity of study designs, and lack of consistency in the definition of population at risk.

CONCLUSION

Sleep and circadian disturbances are common in people at risk for BD. However, the pathophysiology of these alterations and the impact on BD onset are still unclear.

Repeated salivary daytime cortisol and onset of mood episodes in offspring of bipolar parents

Background

Differences in cortisol secretion may differentiate individuals at high compared to low genetic risk for bipolar disorder (BD) and predict the onset or recurrence of mood episodes. The objectives of this study were to determine if salivary cortisol measures are: (1) different in high-risk offspring of parents with BD (HR) compared to control offspring of unaffected parents (C), (2) stable over time, (3) associated with the development of mood episode onset/recurrence, and (4) influenced by comorbid complications.

Methods

Fifty-three HR and 22 C completed salivary cortisol sampling annually for up to 4 years in conjunction with semi-structured clinical interviews. The cortisol awakening response (CAR), daytime cortisol [area under the curve (AUC)], and evening cortisol (8:00 p.m.) were calculated.

Results

There were no differences in baseline CAR, AUC and evening cortisol between HR and C (p = 0.38, p = 0.30 and p = 0.84), respectively. CAR, AUC and evening cortisol were stable over yearly assessments in HR, while in Cs, evening cortisol increased over time (p = 0.008), and CAR and AUC remained stable. In HR, AUC and evening cortisol increased the hazard of a new onset mood disorder/recurrence by 2.7 times (p = 0.01), and 3.5 times (p = 0.01), respectively, but this was no longer significant after accounting for multiple comparisons.

Conclusions

Salivary cortisol is stable over time within HR offspring. However, between individuals, basal salivary cortisol is highly variable. More research is needed, with larger samples of prospectively studied HR youth using a more reliable method of cortisol measurement, to determine the potential role of cortisol in the development of mood disorders.

Electronic supplementary material

The online version of this article (doi:10.1186/s40345-016-0053-5) contains supplementary material, which is available to authorized users.

The HPA axis in bipolar disorder: Systematic review and meta-analysis

OBJECTIVES

To provide a quantitative and qualitative synthesis of the available evidence on the role of Hypothalamic-Pituitary-Adrenal (HPA) axis in the pathophysiology of Bipolar Disorder (BD).

METHODS

Meta-analysis and meta-regression of case-control studies examining the levels of cortisol, ACTH, CRH levels. Systematic review of stress reactivity, genetic, molecular and neuroimaging studies related to HPA axis activity in BD.

RESULTS

Forty-one studies were included in the meta-analyses. BD was associated with significantly increased levels of cortisol (basal and post-dexamethasone) and ACTH, but not of CRH. In the meta-regression, case-control differences in cortisol levels were positively associated with the manic phase (p=0.005) and participants' age (p=0.08), and negatively with antipsychotics use (p=0.001). Reviewed studies suggest that BD is associated with abnormalities of stress-related molecular pathways in several brain areas. Variants of HPA axis-related genes seem not associated with a direct risk of developing BD, but with different clinical presentations. Also, studies on unaffected relatives suggest that HPA axis dysregulation is not an endophenotype of BD, but seems related to environmental risk factors, such as childhood trauma. Progressive HPA axis dysfunction is a putative mechanism that might underlie the clinical and cognitive deterioration of patients with BD.

CONCLUSIONS

BD is associated with dysfunction of HPA axis activity, with important pathophysiological implications. Targeting HPA axis dysfunctions might be a novel strategy to improve the outcomes of BD.

Infants at familial risk for depression show a distinct pattern of cortisol response to experimental challenge

BACKGROUND

The aim of the study was to examine the link between maternal depression and the infant's HPA axis functioning in relation to a sequence of emotional challenges at 12 months postpartum, while controlling for maternal anxiety disorder and general sociodemographic risk.

METHOD

Two hundred and fifty-seven infants whose mothers had been interviewed in pregnancy, as part of a prospective longitudinal study of a nationally representative sample of U.K. families, were individually tested in the laboratory and then observed during a simulated birthday party scenario. Three cortisol samples were taken over the course of 1½ h of afternoon testing.

RESULTS

The cortisol levels of infants whose mothers had no history of depression decreased significantly after individual testing, and rose again significantly in response to the birthday party challenge. In contrast, infants whose mothers had been diagnosed with depression before conception, during pregnancy or in the first 6 months postpartum showed no decrease from the initially elevated levels at entry to the laboratory and a less marked increase in response to the party.

LIMITATIONS

The study does not employ a traditional stress paradigm; instead it introduces a novel design to assess HPA axis functioning in relation to everyday emotional challenges.

CONCLUSIONS

The findings suggest that altered responses to mildly challenging events in infancy may be a marker for infants' familial risk for depressive illness.

Mood and metabolic consequences of sleep deprivation as a potential endophenotype' in bipolar disorder

It has been commonly recognized that circadian rhythm and sleep/wake cycle are causally involved in bipolar disorder. There has been a paucity of systematic research considering the relations between sleep and mood states in bipolar disorder. The current study examines the possible influences of sleep deprivation on mood states and endocrine functions among first-degree relatives of patients with bipolar disorder and healthy controls. Blood samples were taken at two time points in the consecutive mornings at predeprivation and postdeprivation periods. Participants simultaneously completed the Profiles of Mood States at two time points after giving blood samples. Plasma T3 and TSH levels increased after total sleep deprivation in both groups. Sleep deprivation induced TSH levels were reversely associated with depression-dejection among healthy controls. A paradoxical effect was detected for only the first-degree relatives of the patients that changes in plasma cortisol levels negatively linked to depression-dejection and anger-hostility scores after total sleep deprivation. Plasma DHEA levels became correlated with vigor-activity scores after sleep deprivation among first-degree relatives of bipolar patients. On the contrary, significant associations of depression-dejection, anger-hostility, and confusion-bewilderment with the baseline plasma DHEA levels became statistically trivial in the postdeprivation period. Findings suggested that first-degree relatives of patients with bipolar disorder had completely distinct characteristics with respect to sleep deprivation induced responses in terms of associations between endocrine functions and mood states as compared to individuals whose relatives had no psychiatric problems. Considering the relationships between endocrine functions and mood states among relatives of the patients, it appears like sleep deprivation changes the receptor sensitivity which probably plays a pivotal role on mood outcomes among the first-degree relatives of patients with bipolar disorder.

Long-term cortisol in bipolar disorder: associations with age of onset and psychiatric co-morbidity

INTRODUCTION

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is hypothesized to play a role in the pathogenesis of bipolar disorder (BD). Conflicting results have been reported when saliva or serum was used to measure cortisol levels. A recently developed method is to measure cortisol in scalp hair, with 1cm of scalp hair representing 1 month. We studied whether there are differences in long-term hair cortisol levels between BD patients and healthy individuals and whether there are associations between hair cortisol and disease characteristics.

METHODS

Hair samples were collected in 100 BD patients and 195 healthy controls. Long-term cortisol levels were determined in 3 cm hair segments. Saliva samples were collected on two consecutive evenings. Documented disease characteristics were disease state, age of onset and psychiatric co-morbidity.

RESULTS

Hair cortisol levels were not statistically different in BD patients compared to healthy controls (p=0.233) and were not associated with the disease state at the moment of sample collection (p=0.978). In the subgroup of patients with age of onset ≥ 30 years, hair cortisol levels were significantly elevated compared to the subgroup with age of onset <30 years and to healthy controls (p=0.004). Psychiatric co-morbidity was associated with elevated cortisol levels (44.87 versus 31.41 pg/mg hair; p=0.021), with the exclusion of panic disorder, which was associated with decreased cortisol levels (22.13 versus 34.67 pg/mg hair; p=0.019).

CONCLUSIONS

Elevated long-term cortisol levels might play a role in a subgroup of patients with BD. There may be differences in pathogenesis of younger and older onset BD suggesting two different disease entities.

Glucocorticoid receptor BclI polymorphism associates with immunomodulatory response to stress hormone in human peripheral blood mononuclear cells

Glucocorticoid receptor (GR) variants have been found to be associated with stress-related disorders. Our previous in vivo study revealed that the CC allele of GR BclI single-nucleotide polymorphism (SNP) was more common in the high-stress group, which had lower levels of both regulatory T cells (Treg) and Th1 cytokine. The current study was to investigate the associations between GR BclI polymorphism and immunomodulatory response to stress hormone in vitro in human peripheral blood mononuclear cells (PBMC). Blood samples were collected from 18 normal volunteers including 9 subjects with BclI polymorphism GG allele and 9 with wild-type (WT) CC allele. PBMC were cultured with 10(-8) m dexamethasone (DEX), which mimics the plasma cortisol level observed during periods of psychological stress for 24 h and 11 days. Gene expressions of transcription factors, stress hormone and cytokine receptors were analysed by real-time RT-PCR. FoxP3 mRNA was significantly altered in the BclI WT (decreased at 24 h and increased at 11 days) but not in the GG allele. GR mRNA was up-regulated at 24 h and down-regulated at 11 days in CC alleles (P < 0.01 and P < 0.05), rather than in GG alleles. The expression of β-2 adrenergic receptor (β2AR) was increased at 24 h in both CC and GG alleles (P < 0.01 and P < 0.001), but decreased significantly at 11 days in only GG alleles. Expression of T-bet and GATA-3 was altered simultaneously in 24-h culture with DEX from both groups. The BclI polymorphism of GR identifies different immunomodulatory responses to corticosteroids, which may explain, at least in part, the variability in individual sensitivity to stressors.

Biological indicators of illness risk in offspring of bipolar parents: targeting the hypothalamic-pituitary-adrenal axis and immune system

AIM

The study aims to provide a selective review of the literature pertaining to the hypothalamic-pituitary-adrenal (HPA) axis and immune abnormalities as informative biological indicators of vulnerability in bipolar disorder (BD).

METHOD

We summarize key findings relating to HPA axis and immunological abnormalities in bipolar patients and their high-risk offspring. Findings derive from a review of selected original papers published in the literature, and supplemented by papers identified through bibliography review. Neurobiological findings are discussed in the context of emergent BD in those at genetic risk and synthesized into a neurodevelopmental model of illness onset and progression.

RESULTS

BD is associated with a number of genetic and possibly epigenetic abnormalities associated with neurotransmitter, hormonal and immunologically mediated neurobiological pathways. Data from clinical and high-risk studies implicate HPA axis and immune system abnormalities, which may represent inherited vulnerabilities important for the transition to illness onset. Post-mortem and clinical studies implicate intracellular signal transduction processes and disturbance in energy metabolism associated with established BD. Specifically, long-standing maladaptive alterations such as changes in neuronal systems may be mediated through changes in intracellular signalling pathways, oxidative stress, cellular energy metabolism and apoptosis associated with substantial burden of illness.

CONCLUSIONS

Prospective longitudinal studies of endophenotypes and biomarkers such as HPA axis and immune abnormalities in high-risk offspring will be helpful to understand genetically mediated biological pathways associated with illness onset and progression. A clinical staging model describing emergent illness in those at genetic risk should facilitate this line of investigation.

Salivary cortisol in ambulatory assessment--some dos, some don'ts, and some open questions

The impact of stress on health and disease is an important research topic in psychosomatic medicine. Because research on hypothalamic-pituitary-adrenal (HPA) axis regulation under controlled laboratory studies lacks ecological validity, it needs to be complemented by a research program that includes momentary ambulatory assessment. The measurement of salivary cortisol offers the possibility to trace the free steroid hormone concentrations in ambulant settings. Therefore, in this article, we first discuss the role of salivary cortisol in ambulatory monitoring. We start with a brief description of HPA axis regulation, and we then consider cortisol assessments in other organic materials, followed by a presentation of common salivary markers of HPA axis regulation suitable for ambulatory assessment. We further provide an overview on assessment designs and sources of variability within and between subjects (intervening variables), acknowledge the issue of (non)compliance, and address statistical aspects. We further give an overview of associations with psychosocial and health-related variables relevant for ambulatory assessment. Finally, we deal with preanalytical aspects of laboratory salivary cortisol analysis. The relative simplicity of salivary cortisol assessment protocols may lead to an overoptimistic view of the robustness of this method. We thus discuss several important issues related to the collection and storage of saliva samples and present empirical data on the stability of salivary cortisol measurements over time.

Plasma cortisol in first episode drug-naïve mania: differential levels in euphoric versus irritable mood

BACKGROUND

Dysregulation of HPA axis has been widely described in subjects with bipolar disorder (BD), including changes in cortisol levels during mood episodes and euthymia. However, most of the studies were done with medicated BD patients with variable length of illness, which was shown to interfere on peripheral cortisol levels. Therefore, the present study aims to evaluate plasma cortisol levels in drug-naïve BD subjects during the first manic episode, as well as investigate the relationship between plasma cortisol levels and manic symptomatology.

METHODS

Twenty-six drug-naïve patients were enrolled meeting criteria for a first manic episode in bipolar I disorder. Severity of mania was assessed using the Young Mania Rating Scale (YMRS). The control group included 27 healthy subjects matched by age and gender. Cortisol was quantified using a direct radioimmunoassay.

RESULTS

Plasma cortisol levels were decreased during first manic episode compared to healthy controls. Higher cortisol levels were positively associated with the presence of irritability (dysphoria), while elated mania showed lower cortisol levels compared to controls.

LIMITATION

Data including larger samples are lacking.

CONCLUSION

Higher cortisol in dysphoric mania compared to predominantly elated/euphoric mania may indicate a clinical and neurobiological polymorphic phenomenon, potentially involving a higher biological sensitivity to stress in the presence of irritable mood. The present findings highlight the importance to add a dimensional approach to the traditional categorical diagnosis for future neurobiological studies in BD.

Associations between suicide attempts and elevated bedtime salivary cortisol levels in bipolar disorder

BACKGROUND

Hypothalamic-pituitary-adrenal (HPA) axis abnormalities have been reported in bipolar disorder and also in suicidal behavior, but few studies have examined the relationship between suicidal behaviors and the HPA axis function in bipolar disorder, attending to and minimizing confounding factors. We compare HPA axis activity in bipolar individuals with and without suicidal behavior and unaffected healthy controls through measurement of salivary cortisol.

METHOD

Salivary cortisol was collected for three consecutive days in 29 controls, 80 bipolar individuals without a history of suicide and 56 bipolar individuals with a past history of suicide. Clinical factors that affect salivary cortisol were also examined.

RESULTS

A past history of suicide was associated with a 7.4% higher bedtime salivary cortisol level in bipolar individuals. There was no statistical difference between non-suicidal bipolar individuals and controls in bedtime salivary cortisol and awakening salivary cortisol was not different between the three groups.

LIMITATIONS

The measure of salivary cortisol was a home based collection by the study subjects and the retrospective clinical data was primarily based on their historical account.

CONCLUSIONS

Bipolar individuals with a past history of suicidal behavior exhibit hyperactivity in the HPA axis. This biological marker remains significant regardless of demographic factors, mood state, severity and course of illness. This finding in bipolar disorder is consistent with the evidence for altered HPA axis functioning in suicide and mood disorders and is associated with a clinical subgroup of bipolar patients at elevated risk for suicide based on their history, and in need of further attention and study.

Co-occurring manic symptomatology influences HPA axis alterations in depression

Although dysfunctioning of the HPA axis is considered to be a core pathophysiological process in mood disorders, the evidence with regard to depression remains conflicting. This could partly be due to the large heterogeneity within mood disorders, since HPA axis abnormalities may also be associated with the extent of co-occurring manic symptomatology as is seen in bipolar disorder. In this study, patients with depressive disorder and bipolar spectrum disorders were studied with regard to their HPA axis functioning. In 304 healthy controls, 1,134 patients with pure unipolar depressive disorder (UP), and 133 bipolar spectrum disorder patients (BD spectrum), cortisol was measured in 7 saliva samples to determine the 1 h cortisol awakening response (CAR), evening cortisol levels and cortisol suppression after a 0.5 mg dexamethasone suppression test. Both patient groups had overall higher CAR levels compared to controls, but only UP patients showed a higher increase over time in the CAR. A linear association was found between increasing bipolarity and cortisol diurnal slope: BD spectrum patients had a significantly higher diurnal slope than UP patients. Dexamethasone suppression did not differ between mood disorder diagnoses. The heterogeneity in HPA axis functioning in patients with depression can partially be explained by co-existing manic symptomatology, since an increase in the CAR appears to be more specific for pure depression whereas the presence of bipolarity is associated with an increase in the diurnal slope of cortisol.

Elevated daytime cortisol levels: a biomarker of subsequent major affective disorder?

BACKGROUND

Several studies have reported that the offspring of parents with affective disorders secrete high levels of daytime cortisol. A few studies have shown that high cortisol levels preceded the onset of affective symptoms. Only one study to date has found that an elevation in cortisol preceded the onset of an affective disorder, but this was observed only in those youth carrying the short allele of the serotonin transporter gene promoter polymorphism (Goodyer et al., 2009).

METHODS

We followed 28 offspring of parents with bipolar disorder and 31 offspring of parents with no affective disorder from an average age of 17.5years to an average age of 20.0years to determine if cortisol levels at baseline predicted the subsequent development of an affective disorder. At baseline and at follow-up participants completed a diagnostic assessment, and at baseline they provided saliva samples. Daytime cortisol levels were computed as the mean of eight to 24 samples measured across two to six days.

RESULTS

Among the 59 participants, cortisol levels at the mean age of 17.5years predicted the development of an affective disorder during the subsequent 2.5year (odds ratio: 2.1, 95% confidence interval=1.0-4.1, p<0.05) after controlling for offspring mental disorders at the first assessment and having a parent with bipolar disorder.

LIMITATIONS

The findings should be interpreted with caution, as the sample size was small.

CONCLUSION

Elevated daytime cortisol levels in late adolescence may be a biomarker of vulnerability for affective disorders.

Pituitary volume in patients with bipolar disorder and their first-degree relatives

BACKGROUND

Hypothalamic-pituitary-adrenal (HPA) axis dysregulation has been reported in bipolar disorder (BD), but previous magnetic resonance imaging (MRI) studies of pituitary gland volume in BD have yielded inconsistent findings. In addition, the contribution of genetic factors to the pituitary changes in BD remains largely unknown.

METHOD

We used MRI to investigate the pituitary volume in 29 remitted patients with BD, 49 of their first-degree relatives (of whom 15 had a diagnosis of Major Depressive Disorder), and 52 age- and gender-matched healthy controls.

RESULTS

BD patients had a significantly larger pituitary volume compared with their relatives and healthy controls. Pituitary volume did not differ between controls and healthy relatives or relatives diagnosed with major depression.

LIMITATIONS

Direct measures of HPA function (i.e., hormonal levels) were not available.

CONCLUSIONS

These findings suggest that enlarged pituitary volume is associated with disease expression but not genetic susceptibility to BD.

Pediatric bipolar disorder: evidence for prodromal states and early markers

BACKGROUND

Childhood bipolar disorder remains a controversial but increasingly diagnosed disorder that is associated with significant impairment, chronic course and treatment resistance. Therefore, the search for prodromes or early markers of risk for later childhood bipolar disorder may be of great importance for prevention and/or early identification.

METHODS

Literature searches were conducted to identify reviews, case reports and empirical papers addressing the issue of prodromes of childhood bipolar disorder.

RESULTS

A total of 54 articles were found that related to bipolar prodromes, risk factors for later childhood bipolar disorder, childhood risk for adult bipolar disorder, mania manifestations in early childhood, and neuropsychological and biological markers of childhood bipolar disorder. A review of articles suggest (a) childhood bipolar prodromes may be detectable prior to the onset of the disorder, (b) prodromal symptoms may display episodicity during childhood, (c) there is evidence of possible endophenotypic markers such as deficits in executive function, sustained attention, and emotion labeling, (d) there is a potential association with functional, structural, and biochemical alterations evident in brain structures involved in mood regulation, (e) a link between childhood bipolar disorder with early tempermental markers, such as emotional regulation and behavioral disinhibition and (f) there is some early but promising evidence of effective psychotherapeutic preventions.

CONCLUSIONS

There has been very limited investigation of early prodromes of childhood bipolar disorder. Based on the promising findings of prodromes as well as high-risk states and possible endophenotypic markers, more controlled and targeted investigations into the early markers of bipolar disorder appear warranted and potentially fruitful. Until such longitudinal studies with appropriate controls are conducted, specific markers for bipolar prodromes will remain elusive, although evidence suggests they are manifest in at least some subgroups. The finding of promising psychotherapeutic prevention programs underscores the need to find specific and sensitive markers of bipolar prodromes in childhood.

The early stages of bipolar disorder and recent developments in the understanding of its neurobiology

Bipolar disorder is a severe recurrent psychiatric illness that often manifests in adolescence, a time of marked neurobiological change. The current model is one of multiple susceptibility genes interacting with other risk factors leading to alterations in the normal maturational trajectory of the CNS. Longitudinal studies of children of affected parents has enabled mapping of the early natural history of bipolar disorder. Convergent evidence from longitudinal high-risk studies suggest that bipolar disorder evolves in a series of clinical stages from nonspecific childhood disorders to depressive disorders in early adolescence and bipolar spectrum disorders in later adolescence and adulthood. At present, genetic studies and research into specific biological markers in bipolar patients and their family members are underway. Advances in understanding the neurobiological underpinnings of bipolar disorder will require addressing etiological heterogeneity of bipolar disorder and refining the phenotypic definition. In the latter case, the staging model may be a helpful organizing framework.

High cortisol levels in the offspring of parents with bipolar disorder during two weeks of daily sampling

OBJECTIVES

The hypothalamic-pituitary-adrenal (HPA) axis is compromised in major depression, bipolar disorder (BD), and in the offspring of parents with major depression. Less is known about the offspring of parents with BD (FH+). The present project provides follow-up to a previous study showing that the adolescent (mean age 16.7 years) FH+ offspring had higher salivary cortisol levels than the offspring of parents with no mental disorder (FH-) throughout the day in their natural environment, and that girls had higher cortisol levels than boys (Ellenbogen MA, Hodgins S, Walker C-D, Adam S, Couture S. Daytime cortisol and stress reactivity in the offspring of parents with bipolar disorder. Psychoneuroendocrinology 2006; 31: 1164-1180). The goal of the present study was to determine whether FH+ offspring, approximately two years later, continued to exhibit elevated cortisol levels relative to FH- offspring during two weeks of daily sampling.

METHODS

The present study examined salivary cortisol levels in 24 (18.3 +/- 2.6 years) FH+ and 22 (18.0 +/- 2.3 years) FH- offspring who are part of the same longitudinal cohort as the previous study. Saliva was collected at 1300 h and 1500 h in the natural environment of the offspring during 14 consecutive days.

RESULTS

Multilevel modelling analyses indicated that FH+ offspring had higher afternoon levels of cortisol in their natural environment than FH- offspring, but group differences in slope and gender differences were not found.

CONCLUSIONS

The FH+ offspring exhibited increased daytime secretion of cortisol that, at the level of the group, persisted into late adolescence and young adulthood. Perhaps this change in HPA functioning is associated with an increased vulnerability for the development of an affective disorder.

Human models in acute and chronic stress: assessing determinants of individual hypothalamus-pituitary-adrenal axis activity and reactivity

Stress is one of the most significant health problems in modern societies and the 21st century. This explains a pressing need for investigations into the biological pathways linking stress and health. Besides the locus coeruleus-noradrenaline/autonomic (sympathetic) nervous system ( Chrousos and Gold 1992 ), the hypothalamus-pituitary-adrenal (HPA) axis is the major physiological stress response system in the body. Since alterations in HPA axis regulation under basal conditions and in response to acute stress appear to be a close correlate or even a determining factor of the onset of different diseases or disease progression ( Holsboer 1989 ; Chrousos and Gold 1992 ; Tsigos and Chrousos 1994, 2002 ; Stratakis and Chrousos 1995 ; McEwen 1998 ; Heim et al. 2000a ; Raison and Miller 2003 ), the characterization of an individual's HPA axis activity as well as reactivity pattern to psychosocial stress appears to be of major interest. It is obvious that such a research agenda substantially depends on the availability of appropriate measures. However, since the HPA axis is a highly adaptive system which is characterized by marked inter- and intraindividual variability ( Mason 1968 ; Hellhammer et al. 2009 ), the development of such markers of HPA axis regulation in humans was-and still is-a rather challenging task. In this brief review, we focus on findings on two HPA axis measures, namely the cortisol-awakening response (CAR) to assess HPA axis basal activity and the Trier social stress test (TSST) to investigate HPA axis stress reactivity.

Increased pituitary volume in patients with established bipolar affective disorder

Hypothalamic-pituitary-adrenal (HPA) axis dysfunction has been demonstrated in bipolar disorder (BD), but previous magnetic resonance imaging (MRI) studies of pituitary gland volume in BD have reported variable findings. In this MRI study we investigated pituitary volume in 26 patients with established bipolar I disorder (8 males and 18 females, mean age=38.4 years) and 24 matched controls (7 males and 17 females, mean age=38.7 years). The BD patients had a significantly larger pituitary volume as compared with controls, but there was no association between pituitary volume and illness duration, number of manic/depressive episodes, daily medication dosage, family history, or clinical subtype (i.e., psychotic and nonpsychotic). Pituitary volume was larger in females than in males for both groups. These results support previous neuroendocrine findings that implicate HPA axis dysfunction in the core pathophysiological process of BD.

Structure provided by parents in middle childhood predicts cortisol reactivity in adolescence among the offspring of parents with bipolar disorder and controls

Recent studies suggest that childhood exposure to adversity influences later functioning of the hypothalamic-pituitary-adrenal (HPA) axis. Parenting style in childhood, a putative moderator of adversity, may be important in determining HPA reactivity in adolescence. As part of a prospective, longitudinal study, saliva was collected at awakening and 30 and 60 min later over 2 days among 27 offspring of parents with bipolar disorder (high risk; 16.7+/-1.5 years) and 26 offspring of parents with no mental disorders (low risk; 16.2+/-1.7 years). In addition, 24 of the high risk and 22 of the low risk adolescents completed the "Trier Social Stress Test" (TSST). Parents had rated their parenting style when their offspring were 6-13 years of age. Low levels of structure (i.e. organization and consistency) provided by parents in middle childhood were predictive of an elevated cortisol response following awakening (beta=-0.36; p<0.05) and during the TSST (beta=-0.33; p<0.05), even while controlling for risk group. These associations were independent of other indices of environmental risk, and of adolescents' mood and behavior. The level of structure provided by parents in childhood predicted independent measures of cortisol reactivity in adolescence, suggesting that parenting style may regulate different aspects of HPA reactivity.

Functional polymorphism of the glucocorticoid receptor gene associates with mania and hypomania in bipolar disorder

OBJECTIVES

In affective disorders, dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis is a frequently observed phenomenon. Subtle changes in glucocorticoid receptor (GR) functioning caused by polymorphisms of the GR gene (NR3C1) may be at the base of the altered reaction of the HPA axis to stress and subsequently related to the development and course of affective disorders. The aim of our study is to evaluate associations between GR gene polymorphisms and bipolar disorder (BD).

METHODS

In this study, 245 patients with BD were interviewed to confirm diagnosis and BD subtype. Data on medication use and sociodemographic details were also collected. The control group consisted of 532 healthy blood donors, from which data on sex and age were collected. To perform genotyping, blood was collected from all patients and healthy controls.

RESULTS

A trend was found for a protective effect of the exon 9beta polymorphism (p = 0.14) and the TthIIII polymorphism (p < 0.05) on the manifestation of the disease. These effects were significantly influenced by male gender for both polymorphisms. Patients with BD and the A/G variant in exon 9beta had significantly fewer manic and hypomanic episodes than noncarriers (p < 0.05). No further associations were found with the other investigated GR gene polymorphisms and BD. These findings were not corrected for multiple comparisons.

CONCLUSIONS

We conclude that the exon 9beta polymorphism and the TthIIII polymorphism of the GR gene may be associated with a protective effect on the clinical manifestation and course in patients with BD. Furthermore, no associations were found between the other studied GR gene polymorphisms and this disease.

Salivary cortisol in unaffected twins discordant for affective disorder

Dysfunction in the hypothalamic-pituitary-adrenal (HPA) axis has been proposed as a biological endophenotype for affective disorders. In the present study the hypothesis that a high genetic liability to affective disorder is associated with higher cortisol levels was tested in a cross-sectional high-risk study. Healthy monozygotic (MZ) and dizygotic (DZ) twins with (High-Risk twins) and without (Low-Risk twins) a co-twin history of affective disorder were identified through nationwide registers. Awakening and evening salivary cortisol levels were compared between the 190 High- and Low-Risk twins. The 109 High-Risk twins had significantly higher evening cortisol levels than the 81 Low-Risk MZ twins, also after adjustment for age, sex, and the level of subclinical depressive symptoms. No significant difference was found in awakening cortisol levels between High-Risk and Low-Risk twins. In conclusion, a high genetic liability to affective disorder was associated with a higher evening cortisol level, but not with awakening cortisol level. Future prospective family, high-risk and twin studies are needed to decide whether abnormalities in the HPA axis can be identified as an endophenotype of affective disorder.

Neurodevelopmental basis of bipolar disorder: a critical appraisal

Neurodevelopmental factors have been implicated in the pathophysiology of mental disorders. However, the evidence regarding their role in bipolar disorder is controversial. We reviewed the pertinent literature searching for evidence regarding a neurodevelopmental origin of bipolar disorder. Findings from clinical, epidemiological, neuroimaging, and post-mortem studies are discussed, as well as the implications of the available data for a better understanding of the mechanisms involved in the genesis of bipolar disorder. While some evidence exists for developmental risk factors in bipolar disorder, further research is needed to determine the precise extent of their contribution to pathogenesis. The timing and course of such developmentally mediated neurobiological alterations also need to be determined. Of particular importance for further study is the possibility that bipolar disorder may be mediated by an abnormal maturation of brain structures involved in affect regulation.

Corticosteroid receptor-gene variants: modulators of the stress-response and implications for mental health

The stress-response, including autonomic and hypothalamic-pituitary-adrenal (HPA) axis reactivity, is essential for maintaining homeostasis during a challenge. Brain mineralocorticoid receptors and glucocorticoid receptors operate in balance to coordinate the stress-response. Genetic variants in both the human mineralocorticoid and glucocorticoid receptor-genes have been functionally characterized. In vitro effects of these genetic variants on transactivation and mRNA stability have been described. In vivo, two mineralocorticoid receptor-gene SNPs (-2 G/C (allele frequency: 50%), MR I180V (11%)) and four glucocorticoid receptor-gene SNPs (ER22/23EK (3%), N363S (4%), BclI (37%), A3669G (15%)) are associated with changes in hypothalamic-pituitary-adrenal (HPA) axis reactivity. Importantly, the two mineralocorticoid receptor-gene variants (but none of the glucocorticoid receptor-gene variants) also associate with changes in autonomic output as measured as increased heart beat following a psychosocial stress (TSST). Moreover, several of these mineralocorticorticoid receptor- and glucocorticoid receptor variants have been found associated with stress-related disorders, including depression. These data indicate that dysregulation of mineralocorticoid- and glucocorticoid receptor are causative in the pathogenesis of depression. Moreover, these mineralocorticoid- and glucocorticoid receptor-gene variants constitute part of the genetic make up that determines individual stress-responsiveness inducing vulnerability to disease. Furthermore, mineralocorticoid- and glucocorticoid receptors are drug targets, thereby aiming at the underlying mechanisms of stress-related disorders.

Pituitary gland volume in adolescent and young adult bipolar and unipolar depression

OBJECTIVES

Few studies have examined pituitary gland size in mood disorders, particularly in adolescents. We hypothesized increase in the pituitary gland size in early-onset mood disorders.

METHODS

Thirty subjects between the ages of 13 and 20 years participated in the study. Three groups (control, bipolar I depression and unipolar depression) of 10 subjects each (4 male, 6 female) underwent volumetric magnetic resonance imaging at 1.5 T.

RESULTS

Analysis of covariance (covarying for age, sex and intracranial volume) revealed a significant difference in pituitary gland volume amongst the groups [F(2,24) = 7.092, p = 0.014]. Post hoc analysis revealed that controls had a significantly smaller pituitary gland volume than both bipolar patients (p = 0.019) and depressed patients (p = 0.049). Bipolar and depressed subjects did not differ significantly from each other with regard to pituitary gland volume (p = 0.653). Control females had larger pituitary glands than control males [F(1,8) = 10.523, p = 0.012], but no sex differences were noted in the mood disorder groups.

CONCLUSIONS

Pituitary glands are enlarged in adolescents with mood disorders compared to controls. Healthy young females have larger pituitary glands than males, but such a difference is not evident in individuals with unipolar depression or bipolar disorder. These findings provide new evidence of abnormalities of the pituitary in early onset mood disorders, and are consistent with neuroendocrine dysfunction in early stages of such illnesses.

Corticosteroid receptor polymorphisms: determinants of vulnerability and resilience

Why some individuals thrive and others break down under similar adverse conditions, is a central question in the neuroendocrinology of stress related psychopathology. The brain mineralocorticoid (MR) and glucocorticoid receptors (GR) operate in balance to coordinate behavioural, autonomic and neuroendocrine response patterns involved in homeostasis and health. Genetic variants of both the MR and GR have been functionally characterized. The four GR-gene single nucleotide polymorphisms (SNPs) (ER22/23EK (allele frequency: 3%), N363S (4%), BclI (37%), A3669G (15%)) and the two MR-gene SNPs (-2 G/C (50%), MR-I180V (11%)) showed in vitro changes in transactivational capacity, or affect stability of the mRNA (GR exon 9beta A3669G). All of these MR-and GR-SNPs change the regulation of the hypothalamus-pituitary-adrenal (HPA) axis at different levels including basal level (-2 G/C), dexamethasone induced negative feedback (ER22/23EK, N363S, BclI, 9beta A3669G) or following a psychosocial stress test (Trier Social Stress Test (TSST); all of the MR-and GR-SNPs). Importantly, the MR-I180V increased autonomic output and enhanced cortisol secretion during the TSST. Recently, several of these MR-and GR-variants have been found associated with psychopathology (depression, bipolar disorder). These data provide evidence that dysregulation of MR and GR are causative in the pathogenesis of depression and that these MR-and GR-gene variants are part of the genetic make up that determines individual stress-responsivity and coping style, affecting vulnerability to disease.

Daytime cortisol and stress reactivity in the offspring of parents with bipolar disorder

The hypothalamic-pituitary-adrenal (HPA) axis is compromised in major depression and bipolar disorder (BD). It is not known however whether HPA abnormalities predate the onset of these disorders. Preliminary data indicated that the adolescent offspring of parents with BD (high-risk), as compared to adolescents of parents with no mental disorder (low-risk), had higher levels of daytime salivary cortisol. The present study re-examined the cortisol increase after awakening and basal cortisol levels in a larger sample, and tested the hypothesis that high-risk offspring are more reactive to psychosocial stress than low-risk offspring. Saliva samples were collected from 58 adolescents, 29 high-risk (14 male/15 female, 16.8 years) and 29 (14 male/15 female, 16.6 years) low-risk, in their natural environment during at least two days. Twenty-five high-risk (13 male/12 female) and 25 low-risk (13 male/12 female) youth completed a child adaptation (15 years) or the standard version of the "Trier Social Stress Test". Consistent with our previous finding, high-risk offspring had higher daytime levels of cortisol in their natural environment than low-risk offspring, and the difference was unrelated to clinical symptoms or other known confounds. Irrespective of risk status, female participants had higher daytime levels of cortisol than male participants. In contrast, there were no group differences in the cortisol response to the laboratory psychosocial stressor. The offspring of parents with BD show evidence of increased daytime basal HPA functioning with normal reactivity to psychosocial stress.

Environmental influences on family similarity in afternoon cortisol levels: twin and parent-offspring designs

Modest genetic effects on morning, but not late-day, cortisol levels have been established. Environmental demands may influence basal cortisol levels later in the day. Thus, we anticipated that individuals in the same family would have similar afternoon cortisol levels to the extent that they share aspects of their environment. We examined afternoon basal cortisol levels measured across 3 consecutive days in mothers and fathers and in multiple offspring in two separate large and longitudinal studies. Study I involved 321 families with singletons while study II involved 233 families with twins. Modest family similarity was apparent for afternoon basal cortisol levels in both studies. Spouses' cortisol levels were also correlated. Data from study II demonstrated that family resemblance in afternoon cortisol was accounted for by underlying shared environmental factors, but not underlying genetic factors. Shared environment accounted for 62% of the variation in twin afternoon basal cortisol levels and 14% of the variation in parent afternoon basal cortisol levels. We used pooled data from the two studies to examine whether parental depression, socioeconomic status (SES), and offspring sex and age impacted cortisol levels. Female offspring had higher cortisol levels than males, and cortisol decreased with age until about 9 years of age, after which cortisol increased with age. Family similarity persisted after accounting for parental depression, SES, time of day, and offspring sex and age, which suggests that the shared family environment influences parent and offspring stress hormone levels throughout the childhood years.

Rational approaches to the neurobiologic study of youth at risk for bipolar disorder and suicide

OBJECTIVES

The aims of this paper are to provide an overview of neuroimaging findings specific to bipolar disorder and suicide, and to consider rational approaches to the design of future in vivo studies in youth at risk.

METHODS

Neuroimaging and related neurobiological literature pertaining to bipolar disorder and suicide in adult and pediatric samples was reviewed in a non-quantitative manner.

RESULTS

Specific structural and functional brain findings in bipolar disorder are described, where possible in the context of relevant current neurobiological theories of etiology. Diagnostic and prognostic implications are discussed.

CONCLUSIONS

The simultaneous use of complementary neurobiological approaches may be a powerful way of identifying and validating factors reliably associated with bipolar disorder and suicide. A profile of neurobiological markers with which to screen for bipolar disorder and suicide risk may provide for earlier and more accurate diagnosis, perhaps even in the pre- or subsyndromal stages in high-risk youth.

Salivary cortisol secretion in remitted bipolar patients and offspring of bipolar parents

OBJECTIVES

It is generally believed that cortisol secretion normalizes during clinical remission in mood disorders. However, this assumption has been challenged by preliminary reports of enhanced cortisol secretion in remitted bipolar patients and in the offspring of bipolar parents. The purpose of this study is to replicate findings of increased cortisol secretion during clinical remission in bipolar patients and in the offspring of bipolar parents, rigorously controlling for known confounders.

METHODS

We conducted intensive cortisol sampling (six samples per day for three test days, on three consecutive weekends) on 15 bipolar type I and type II patients and 28 unrelated offspring of bipolar parents. Offspring had a history of unipolar depression. Participation was restricted to cases in complete sustained remission. Controls were matched as closely as possible for age, sex, and education. Mood and sleep measures were recorded on each sampling day.

RESULTS

In total, 743 samples were collected from the patient group and 576 from controls. Correcting for repeat measures, there was no statistically significant difference in cortisol secretion at any sampling time between remitted bipolar patients, remitted offspring of bipolar parents, and normal controls. The cortisol waking response did not differ between patients and controls. Covariates, including sex, age, Beck depression score and hours of sleep, were not statistically significant.

CONCLUSIONS

Our observations are consistent with the view that complete sustained clinical remission is associated with normal salivary cortisol levels throughout the day. A personal or family history of bipolar disorder per se does not appear to confer added risk for increased salivary cortisol secretion during sustained clinical remission.

Post-awakening cortisol secretion during basic military training

Salivary free cortisol concentrations in the first 30 min after awakening were assessed in 12 healthy army recruits at the beginning, middle and end of an 11-week intensive physical training course. To ensure strict adherence to protocol saliva collection was supervised and collected on each sampling day immediately on waking and again 15 and 30 min later. Self-rated psychological assessments of state levels of stress, arousal and fatigue were performed in the evening of each sampling day. A within-subjects repeated-measures analysis of participants who completed the course (12 of the original 20) showed a significant main effect of cortisol concentration across all three sampling points after awakening (F((2,22))=54.516, p<0.0001) and a significant main effect of weeks into the training course (F((3,33))=4.390, p=0.010). Further analysis of this effect of measurement-week revealed that at weeks 3 and 6 total cortisol secretion estimated by area under the curve was lower (F((3,33))=4.602, p=0.008) compared to the beginning and end of the course. Surprisingly self-reported stress, arousal and fatigue did not differ significantly across weeks, despite the large dropout rate (40%) and self-evident pressures of the course. We conclude that when controlling for many confounding variables, including participant adherence, post-awakening cortisol levels are sensitive to stressful challenge over a period of weeks.

Maternal and environmental factors influence the hypothalamic–pituitary–adrenal axis response to corticotropin-releasing hormone infusion in offspring of mothers with or without mood disorders

Individuals with melancholic major depression exhibit basal hypercortisolism and an attenuated ACTH response to exogenous corticotropin-releasing hormone (CRH) infusion. Given the greater incidence of depression in children of depressed parents, we examined the ACTH and cortisol responses to ovine CRH (oCRH) infusion in 63 adolescent offspring of mothers with major depression, bipolar illness, or no psychiatric illness. Psychiatric and observational assessments of these families had been conducted over the course of 10 years preceding this study. We examined the children's responses to CRH in relation to maternal characteristics and family environment and found the following: (a) cortisol responses were negatively related to chronic family stress and (b) offspring of depressed mothers with an avoidant personality disorder showed an exaggerated ACTH response. In addition, adolescents in late puberty (Tanner 4 and 5) had lower ACTH and cortisol responses to oCRH infusion than those in early puberty. Further, offspring with early histories of mood problems, and those who developed major depressive disorder as young adults, did not exhibit basal hypercortisolism but did show an attenuated ACTH response to CRH. Our results add to the growing body of literature showing the influence of maternal characteristics and environmental factors on hypothalamic-pituitary-adrenal axis patterns in children.

Corticosteroid receptor genetic polymorphisms and stress responsivity

A fundamental question in the neuroendocrinology of stress-related psychopathology is why some individuals flourish and others perish under similar adverse conditions. In this contribution we focus on the variants of mineralocorticorticoid (MR) and glucocorticoid receptors (GR) that operate in balance and coordinate behavioral, autonomic, and neuroendocrine response patterns involved in homeostasis and health. In the GR-gene, three single nucleotide polymorphism (SNPs) have been associated with changes in metabolic profile and cardiovascular parameters: the ER22/23EK with a favorable and the N363S and the Bcl1 with a more adverse profile. Importantly, the N363S and the Bcl1 are found to increase cortisol responses to a psychosocial stressor. As a result, the whole body will suffer from overexposure with possible adverse effects on metabolism, cardiovascular control, immune function, and behavior. Also in the MR gene, variants are being identified that are associated with dysregulated autonomic, behavioral, and neuroendocrine responses. The data suggest that these MR and GR variants contribute to individual differences in resilience and vulnerability to stressors, and that these receptors therefore are potential drug targets for recovery of homeostasis and health.

Prenatal anxiety predicts individual differences in cortisol in pre-adolescent children

BACKGROUND

Animal studies suggest that prenatal stress is associated with long-term disturbance in hypothalamic-pituitary-adrenal (HPA) axis function, but evidence in humans is lacking. This study examined the long-term association between prenatal anxiety and measures of diurnal cortisol at age 10 years.

METHODS

Measures of cortisol were collected at awakening, 30 min after awakening, and at 4 pm and 9 pm on 3 consecutive days in a sample of 10-year-olds (n = 74) from the Avon Longitudinal Study of Parents and Children, a prospective longitudinal cohort study of mothers and children on whom measures of anxiety and depression were collected in pregnancy and the postpartum period. Analyses examined the links between symptoms of prenatal anxiety and multiple indicators of cortisol, an index of HPA axis functioning.

RESULTS

Prenatal anxiety was significantly associated with individual differences in awakening and afternoon cortisol after accounting for obstetric and sociodemographic risk (partial correlations were .32 and .25, p < .05). The effect for awakening cortisol remained significant after controlling for multiple postnatal assessments of maternal anxiety and depression.

CONCLUSIONS

This study provides the first human evidence that prenatal anxiety might have lasting effects on HPA axis functioning in the child and that prenatal anxiety might constitute a mechanism for an increased vulnerability to psychopathology in children and adolescents.

Hypothalamic-pituitary-adrenal axis and bipolar disorder

There is robust evidence demonstrating abnormalities of the HPA axis in bipolar disorder. Hypercortisolism may be central to the pathogenesis of depressive symptoms and cognitive deficits, which may in turn result from neurocytotoxic effects of raised cortisol levels. Manic episodes may be preceded by increased ACTH and cortisol levels, leading to cognitive problems and functional impairments. Identification and effective treatment of mood and cognitive symptoms of mood disorders are clinical goals, but currently available treatments may fall short of this ideal. Manipulation of the HPA axis has been shown to have therapeutic effects in preclinical and clinical studies, and recent data suggest that direct antagonism of GRs maybe a future therapeutic strategy in the treatment of mood disorders.

Determinants of salivary cortisol levels in 10-12 year old children; a population-based study of individual differences

The hypothalamic-pituitary-adrenal (HPA)-axis is a central component of the body's neuroendocrine response to stress. Its major end-product cortisol has profound effects on mood and behavior. Although it has often been suggested, it remains unknown whether differences in HPA-axis physiology are part of an individual's vulnerability to psychopathology, and constitute a causal factor in its development. In order to study the contribution of HPA-axis physiology to the development of psychopathology, we measured HPA-axis physiology in a community-cohort of 1768 10-12 year-old children. The aims of the here presented study were twofold: (1) to obtain data on HPA-axis function in a large cohort of pre- and early-adolescent children, both in terms of total hormonal output and in terms of the dynamics of cortisol secretion (by means of the cortisol awakening response); and (2) to study potential confounders of the cortisol-psychopathology relationship in this age group, such as season of sampling, age, gender, pubertal development, perinatal variables and BMI. We found a wide interindividual variability in HPA-axis function. An increase in cortisol in the first 30 min after awakening was present in 70.7% of children, but the increase appears lower in children than in adults. In addition, this study suggests that season of sampling and gender may act as potential confounders in the cortisol-psychopathology relationship. We will follow these children longitudinally for the development of psychopathology in the period from childhood into adulthood. This period covers adolescence, which is a critical time for the appearance and development of psychiatric disorders.

Signaling pathways in brain involved in predisposition and pathogenesis of stress-related disease: genetic and kinetic factors affecting the MR/GR balance

Optimal regulation of the stress response is a prerequisite for adaptation, homeostasis, and health. There are two modes of operation in the stress response. First, an immediate response mode mediated by corticotrophin-releasing hormone-1 (CRH-1) receptors that organizes the behavioral, sympathetic, and hypothalamic-pituitary-adrenal (HPA) response to a stressor. Second, a slower mode, which facilitates behavioral adaptation, promotes recovery, and reestablishes homeostasis. Corticosteroid hormones are implicated in both stress system modes. On the one hand, cortisol and corticosterone determine the threshold or sensitivity of the fast responding mode, whereas the very same hormones in high concentrations facilitate termination of the stress response. In the brain, these actions exerted by the corticosteroid hormones are mediated by two distinct nuclear receptor types, that is, mineralocorticoid receptors (MRs) and glucocorticoid receptors (GRs). Whereas MRs maintain neuronal homeostasis and limit the disturbance by stress, GRs help to recover after the challenge and to store the experience for coping with future encounters. Imbalance in MR/GR-mediated actions compromises homeostatic processes in these neurons, which is thought to underlie maladaptive behavior and HPA dysregulation that may lead to aberrant metabolism, impaired immune function, and altered cardiovascular control. The balance in MR/GR-mediated actions depends on bioavailability of corticosteroids, access to the receptors, the stoichiometry of co-regulators, and other proteins as well as genetic factors, among which single nucleotide polymorphisms (SNPs) of the GRs are extensively documented. Stress can bias the receptor signaling pathways, changing "good" corticosteroid actions into "bad" ones.

Prepubertal bipolar disorder: proper diagnosis should lead to better treatment response

Treatment research in prepubertal bipolar disorder remains in a rudimentary stage. Phenomenological evidence suggests it is a heterogeneous disorder with varying degrees of rapid cycling, aggression, and psychosis often accompanied by comorbid diagnoses of attention deficit hyperactivity disorder, conduct disorder, oppositional defiant disorder, and anxiety disorders including obsessive compulsive disorder. Longitudinal and family history studies suggest prepubertal bipolar disorder may be more treatment-resistant than later-onset bipolar disorder. Neurobiological studies to guide treatment, though promising, remain in their infancy. Clinical trials to date (mostly open studies) often have lumped together subjects with manic, hypomanic, and mixed presentations with different and/or undiagnosed comorbidities, making meaningful comparisons of treatment response difficult. Randomized, double-blind, placebo-controlled trials are needed to clarify best treatment options for bipolar subtypes with and without comorbid disorders. More homogeneous diagnostic groupings based on episode and duration criteria and a more patient-centered, symptom-based approach should be considered in treatment designs.

The impact of high neuroticism in parents on children's psychosocial functioning in a population at high risk for major affective disorder: a family-environmental pathway of intergenerational risk

Behavioral genetic studies indicate that nongenetic factors play a role in the development of bipolar and major depressive disorders. The trait of neuroticism is common among individuals with major affective disorders. We hypothesized that high neuroticism among parents affects the family environment and parenting practices and thereby increases the risk of psychosocial problems among offspring. This hypothesis is tested in a sample of participants at high and low risk for major affective disorders, which contained parents with bipolar disorder (55), major depression (21), or no mental disorder (148) and their 146 children between 4 and 14 years of age. Parents with high neuroticism scores were characterized by low psychosocial functioning, poor parenting, more dependent stressful life events, and the use of more emotion-focused and less task-oriented coping skills. High neuroticism in parents was associated with internalizing and externalizing problems among the children, as assessed by parent and teacher ratings on the Child Behavior Checklist and clinician ratings. The results suggest that high neuroticism in parents with major affective disorders is associated with inadequate parenting practices and the creation of a stressful family environment, which are subsequently related to psychosocial problems among the offspring.