Recent life events, cortisol, dehydroepiandrosterone and the onset of major depression in high-risk adolescents

The role of gene-environment correlations and interactions in middle childhood depressive symptoms

Depression is known to be associated with a wide array of environmental factors. Such associations are due at least in part to genetic influences on both. This issue has been little explored with preadolescent children. Measures of family chaos and parenting style at age 9 and child depressive symptoms at age 12 were completed by 3,258 twin pairs from the Twins Early Development Study and their parents. Quantitative genetic modeling was used to explore common and unique genetic and environmental influences on both family environment and later depressive symptoms. Depressive symptoms at age 12 were significantly heritable. Moderate genetic effects influenced parenting style and family chaos at the age of 9, indicating gene-environment correlation. There were significant genetic correlations between family environment and depressive symptoms. There was some evidence of a Gene × Environment interaction, with stronger genetic effects on depressive symptoms for children with more suboptimal family environment. There was an Environment × Environment interaction, with effects of nonshared environment on depressive symptoms stronger for twins with more adverse parenting experiences. There is some evidence for gene-environment correlation between aspects of family environment in middle childhood and subsequent depressive symptoms. This suggests that one of the mechanisms by which genes lead to depressive symptoms may be by themselves influencing depressogenic environments.

Analysis of baseline hypothalamic-pituitary-adrenal activity in late adolescence reveals gender specific sensitivity of the stress axis

Dysfunctional regulation of the hypothalamic-pituitary-adrenal (HPA) axis has been proposed as an important biological mechanism underlying stress-related diseases; however, a better understanding of the interlinked neuroendocrine events driving the release of cortisol by this stress axis is essential for progress in preventing or halting irreversible development of adverse HPA-function. We aimed to investigate basal HPA-activity in a normal population in late adolescence, the time of life believed to overlap with HPA-axis maturation and establishment of a lasting set point level of HPA function. A total of 1258 participants (mean age 16.6 years) recruited from the Western Australian Pregnancy (Raine) Cohort provided fasting morning blood and saliva samples for basal HPA activity assessment. Irrespective of gender, linear regression modelling identified a positive correlation between the main components of the HPA-cascade of events, ACTH, total cortisol and free cortisol in saliva. Corticosteroid binding globulin (CBG) was inversely associated with free cortisol in saliva, an effect most clearly observed in boys. ACTH levels were lower, but cortisol levels were higher in girls than in boys. Girls may also be exposed to more bioactive cortisol, based on higher average free cortisol measured in saliva at awakening. These relatively higher female free cortisol levels were significantly reduced by oral contraceptive use, eliminating the gender specific difference in salivary cortisol. Free plasma cortisol, calculated from total circulating cortisol and CBG concentrations, was also significantly reduced in girls using oral contraceptives, possibly via an enhancing effect of oral contraceptives on blood CBG content. This study highlights a clear gender difference in HPA activity under non-stressful natural conditions. This finding may be relevant for research into sex-specific stress-related diseases with a typical onset in late adolescence.

Major depression in young girls is related to altered cortisol awakening response

BACKGROUND

There is evidence that clinical depression is associated with elevated basal cortisol levels in adult patients.

OBJECTIVE

The present investigation tries to find out, whether this relationship also holds true in adolescents with major depression.

METHODS

For 131 female subjects (63 MDD, 68 controls) the cortisol awakening response (CAR) was measured at 0, 30, 45, and 60 min after awakening. All subjects provided saliva cortisol.

RESULTS

A significantly higher CAR was found in patients. The global mean difference was due to differences 60 and 45 min after awakening.

LIMITATIONS

A causal interpretation of the data is restricted, because of its cross-sectional nature. The effect size of the mean differences is rather small.

CONCLUSION

The observed HPA hyperactivity may be a cause as well as a consequence of depression in childhood.

Cortisol secretion in depressed, and at-risk adults

Distinct patterns of cortisol secretion have been associated with depression in past research, but it remains unclear whether individuals at-risk for depression may also have similar patterns of cortisol secretion. This is the first study to date of both naturalistic diurnal cortisol secretion and cortisol reactivity to a psychosocial laboratory stressor in depressed and at-risk adults. Cortisol secretion patterns were compared for 57 currently depressed, at-risk (based on trait-level positive and negative affect), and control participants over 5 days and in response to a laboratory stressor. After controlling for potentially confounding biobehavioral variables, the depressed group had a larger cortisol awakening response (CAR) and higher average diurnal cortisol compared to control participants. Individuals at-risk for depression also had significantly higher waking cortisol levels than control participants. Results for the psychosocial laboratory stressor did not show the predicted elevations in cortisol for depressed and at-risk participants compared to controls. The at-risk group recovered more quickly when compared to the depressed group both in levels of cortisol and concurrent measures of negative affect. The at-risk and depressed participants were similar on the diurnal cortisol measures, but differed on response to the laboratory social stressor, suggesting divergence in cortisol secretion patterns between currently depressed and temperamentally at-risk individuals. Further investigation of HPA functioning of individuals at-risk for depression may clarify the stress processes involved in risk for depression onset.

The cortisol awakening response predicts major depression: predictive stability over a 4-year follow-up and effect of depression history

BACKGROUND

The cortisol awakening response (CAR) has been shown to predict major depressive episodes (MDEs) over a 1-year period. It is unknown whether this effect: (a) is stable over longer periods of time; (b) is independent of prospective stressful life events; and (c) differentially predicts first onsets or recurrences of MDEs.

METHOD

A total of 270 older adolescents (mean age 17.06 years at cortisol measurement) from the larger prospective Northwestern-UCLA Youth Emotion Project completed baseline diagnostic and life stress interviews, questionnaires, and a 3-day cortisol sampling protocol measuring the CAR and diurnal rhythm, as well as up to four annual follow-up interviews of diagnoses and life stress.

RESULTS

Non-proportional person-month survival analyses revealed that higher levels of the baseline CAR significantly predict MDEs for 2.5 years following cortisol measurement. However, the strength of prediction of depressive episodes significantly decays over time, with the CAR no longer significantly predicting MDEs after 2.5 years. Elevations in the CAR did not significantly increase vulnerability to prospective major stressful life events. They did, however, predict MDE recurrences more strongly than first onsets.

CONCLUSIONS

These results suggest that a high CAR represents a time-limited risk factor for onsets of MDEs, which increases risk for depression independently of future major stressful life events. Possible explanations for the stronger effect of the CAR for predicting MDE recurrences than first onsets are discussed.

Cortisol and depression: three questions for psychiatry

BACKGROUND

Cortisol plays a multifaceted role in major depression disorder (MDD). Diurnal rhythms are disturbed, there is increased resistance to the feedback action of glucocorticoids, excess cortisol may induce MDD, basal levels may be higher and the post-awakening cortisol surge accentuated in those at risk for MDD. Does this suggest new avenues for studying MDD or its clinical management?

METHOD

The relevant literature was reviewed.

RESULTS

Cortisol contributes to genetic variants for the risk for MDD and the way that environmental events amplify risk. The corticoids' influence begins prenatally, but continues into adulthood. The impact of cortisol at each phase depends not only on its interaction with other factors, such as psychological traits and genetic variants, but also on events that have, or have not, occurred previously.

CONCLUSIONS

This review suggests that the time is now right for serious consideration of the role of cortisol in a clinical context. Estimates of cortisol levels and the shape of the diurnal rhythm might well guide the understanding of subtypes of MDD and yield additional indicators for optimal treatment. Patients with disturbed cortisol rhythms might benefit from restitution of those rhythms; they may be distinct from those with more generally elevated levels, who might benefit from cortisol blockade. Higher levels of cortisol are a risk for subsequent depression. Should manipulation of cortisol or its receptors be considered as a preventive measure for some of those at very high risk of future MDD, or to reduce other cortisol-related consequences such as long-term cognitive decline?

A systematic review of the prevalence and risk factors of depression among iranian adolescents

Depression is the most common mood and psychiatric disorder. The aim of this comprehensive study was to provide a complete picture of the prevalence and risk factors of depression. The study employed a systematic review methodology, searching Iranian and international databases. After screening and evaluating the articles, a synthesis of 53 articles was accumulated. A meta-analysis of the studies showed that the prevalence of children and adolescent depression was 43.55% using the BDI, 15.87 % using SCL-90, and 13.05% using CDI. Also, the prevalence of depression was higher among girls than boys based on the BDI and CDI results. The most important factors contributing to depression were: the female sex, poor inter-parental relationship, poor adolescent-parent relationship, low socio-economic status (SES), state of parenting styles, low level of parental education, and poor academic performance. The comparatively high prevalence of depression among Iranian adolescents call for further investigation and measures.

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.

Dehydroepiandrosterone treatment effects on weight, bone density, bone metabolism and mood in women suffering from anorexia nervosa-a pilot study

We investigated the effects of the administration of dehydroepiandrosterone (DHEA) on weight, bone metabolism, bone density and clinical mood symptoms in outpatient Anorexia Nervosa (AN) patients. AN patients (n=26) were double-blindly randomized to receive DHEA (100mg) or placebo for 6 months. Outcome measures were bone mineral density (BMD) and bone mineral content (BMC) measured by dual energy X-ray absorptiometry (DXA) and metabolism indexes, steroid hormones, and mood and eating disorder symptoms measured at baseline and at the 3 and 6 months follow-up visits. Mood and eating disorder symptoms were assessed monthly by the Beck Depression Inventory, Eating Disorder Inventory and Clinical Global Improvement Scales. No treatment or treatment by time interaction was observed for any bone density measures. Deoxypiridinolyne (DPD) was positively correlated with weight (P=0.02). An increase in body mass index (BMI) in the DHEA group was significantly higher at 4 months compared to the control group (P=0.05). Improvement of mood was significantly correlated with weight only in the DHEA group. Despite a significant decrease in DPD, no improvement in bone mineral density was detected. However, patients treated with DHEA benefited from a significant increase in BMI, which was positively correlated with improvement in mood.

Neuroendocrine predictors of emotional and behavioral adjustment in boys: longitudinal follow-up of a community sample

BACKGROUND

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been observed in adults and children with mood and anxiety disorders and is thought to be involved in the pathogenesis of these disorders. We recently studied a diverse community sample of boys and found associations of behavioral problems, including symptoms of depression and anxiety, with basal and stress-induced cortisol concentrations. Here we examine cortisol-emotional/behavioral associations at a two-year follow-up and test whether initial cortisol is predictive of worsening emotional/behavioral problems two years later.

METHOD

Seventy-eight 10-14-year-old boys and their mothers completed a battery of psychosocial assessments, provided morning and afternoon saliva samples, and participated in a home visit involving mildly stressful tasks and saliva collection for cortisol assay during a two-year follow-up assessment.

RESULTS

Consistent with the findings from our time 1 assessment, greater declines in cortisol across the home-visit challenge task were significantly associated with internalizing and externalizing behaviors as well as attention problems and social problems at the two-year follow-up. In addition, morning and afternoon cortisol concentrations at the initial assessment were significant positive predictors of the later development of child depressive symptoms at follow-up after controlling for initial depressive symptoms.

CONCLUSION

These findings demonstrate that children in the community with internalizing and externalizing behavior problems have altered patterns of HPA axis stress reactivity. In addition, our prospective findings suggest that elevated cortisol concentrations may influence the later development of emotional/behavioral problems in boys.

Interaction between the BDNF gene Val/66/Met polymorphism and morning cortisol levels as a predictor of depression in adult women

BACKGROUND

Common genetic variants, such as the brain-derived neurotrophic factor (BDNF) Val/66/Met polymorphism (rs6265), are known to interact with environmental factors such as early adversity to increase the risk of subsequent major depression. Much less is known about how they interact with individual differences in cortisol, although these also represent a risk for major depression.

AIMS

To determine whether this BDNF variant moderated the risk represented by higher levels of morning salivary cortisol in adult women.

METHOD

We recruited 279 premenopausal women who were at high risk of major depressive disorder because of either negative self-evaluation, unsupportive core relationship or chronic subclinical symptoms of depression or anxiety. Morning salivary cortisol was measured daily for up to 10 days at entry. Participants were followed up for about 12 months by telephone calls at 3-4 monthly intervals. Major depression and severe life events were assessed through interviews at baseline and follow-up; DNA was obtained from the saliva.

RESULTS

There were 53 onsets (19%) of depressive episodes during follow-up. There was a significant U-shaped relationship between adjusted morning cortisol levels at baseline and the probability of depression onset during follow-up. In total, 51% experienced at least one severe life event/difficulty, and this strongly predicted subsequent onsets of depressive episodes. The BDNF Val/66/Met genotype was not directly associated with onsets of depression or with cortisol levels, but there was significant interaction between Val/66/Met and cortisol: the association between baseline cortisol and depression was limited to those with the Val/66/Val variant. There was no interaction between life events and either this BDNF polymorphism or cortisol levels.

CONCLUSIONS

Morning salivary cortisol interacts with the BDNF Val/66/Met polymorphism in predicting new depressive episodes. This paper adds to the evidence that single gene polymorphisms interact with endogenous factors to predict depression.

5-HTTLPR-environment interplay and its effects on neural reactivity in adolescents

It is not known how 5-HTTLPR genotype × childhood adversity (CA) interactions that are associated with an increased risk for affective disorders in population studies operate at the neural systems level. We hypothesized that healthy adolescents at increased genetic and environmental risk for developing mood disorders (depression and anxiety) would demonstrate increased amygdala reactivity to emotional stimuli compared to those with only one such risk factor or those with none. Participants (n = 67) were classified into one of 4 groups dependent on being homozygous for the long or short alleles within the serotonin-transporter-linked polymorphic region (5-HTTLPR) of the SLC6A4 gene and exposure to CA in the first 11 years of life (present or absent). A functional magnetic resonance imaging investigation was undertaken which involved viewing emotionally-salient face stimuli. In addition, we assessed the role of other variables hypothesized to influence amygdala reactivity, namely recent negative life-events (RNLE) assessed at ages 14 and 17, current anxiety symptoms and psychiatric history. We replicated prior findings demonstrating moderation by gene variants in 5-HTTLPR, but found no support for an effect of CA on amygdala reactivity. We also found a significant effect of RNLE aged 17 with amygdala reactivity demonstrating additive, but not interactive effects with 5-HTTLPR. A whole-brain analysis found a 5-HTTLPR × CA interaction in the lingual gyrus whereby CA appears to differentially modify neural reactivity depending on genotype. These results demonstrate that two different forms of environmental adversities interplay with 5-HTTLPR and thereby differentially impact amygdala and cortical reactivity.

Depressive symptoms during adolescence: comparison between epidemiological and high risk sampling

PURPOSE

Both epidemiological (unselected) and high risk (screening on known risk criteria) samplings have been used to investigate the course of affective disorders. Selecting individuals on multiple risk criteria may create a sample not comparable to individuals with similar risk criteria within the general population. This study compared depressive symptoms across the two sampling methods to test this possibility.

METHODS

The high risk Cambridge Hormones and Moods Project (CHAMP) screened and recruited adolescents aged 12 to 16. A total of 905 (710 high risk) individuals participated and were reassessed at three follow-ups. The ROOTS epidemiological sample consisted of 1,208 14-year-olds reassessed at 15.5 and 17 years. The risk profile for CHAMP was recreated in the ROOTS study. Both samples completed the Moods and Feelings Questionnaire, a self-report measure of current depressive symptoms.

RESULTS

Comparing individuals with the same high risk profiles across the CHAMP and ROOTS studies revealed no significant differences in mean depression scores. Combining the samples revealed that for females, mean depression scores were maintained from 12 to 15 years then declined by 17 years. For males, scores declined from 12 throughout adolescence. High risk status led to consistently higher levels of depressive symptoms in female adolescents but result in little change within male adolescents.

CONCLUSIONS

The high risk design recruited adolescents with a depression symptoms profile comparable to the general population for both sexes. High risk status may alter the trajectory of depressive symptoms in female adolescents only. Males may be less sensitive to recent adversity.

Stress and puberty-related hormone reactivity, negative emotionality, and parent--adolescent relationships

Hormone reactivity to stressors and hormones that rapidly change at puberty are hypothesized to influence moods, which may in turn affect parent-child relationship quality. The present study investigated whether reactivity of testosterone, DHEA, and cortisol in a clinic setting (venipuncture paradigm) predicted negative emotionality and family problems at Time 1 (0 months), Time 2 (6 months), and Time 3 (12 months) in a sample of 56 boys (M = 12.72, SD = 1.32 years) and 52 girls (M = 11.99, SD = 1.55 years). Reactivity of each hormone, negative emotionality, and family problems were measured at each of three laboratory visits. Testosterone reactivity at the first assessment predicted family problems one year later. DHEA stress reactivity was related to concurrent negative emotionality at six and 12 months. Cortisol reactivity did not predict negative emotionality or family problems. Reactivity of different hormones that change at puberty may play an important role in adolescent moods and family processes during puberty.

Longitudinal hypothalamic-pituitary-adrenal axis trait and state effects in recurrent depression

BACKGROUND

Hypothalamic-pituitary-adrenal (HPA)-axis hyperactivity has been observed in (recurrent) major depressive disorder (MDD), although inconsistently and mainly cross-sectional. Longitudinal studies clarifying state-trait issues are lacking. We aimed to determine whether HPA-axis (hyper)activity in recurrent MDD is: (I) reflecting a persistent trait; (II) influenced by depressive state; (III) associated with stress or previous episodes; (IV) associated with recurrence; and (V) influenced by cognitive therapy.

METHODS

We included 187 remitted highly recurrent MDD-patients (mean number of previous episodes: 6.3), participating in a randomized-controlled-trial investigating the preventive effect of additional cognitive therapy on recurrence. In an add-on two-staged patient-control and prospective-cohort design, we first cross-sectionally compared patients' salivary morning and evening cortisol concentrations with 72 age- and sex-matched controls, and subsequently longitudinally followed-up the patients with repeated measures after three months and two years.

RESULTS

Patients had higher cortisol concentrations than controls (p<.001), which did not change by MDD-episodes during follow-up. HPA-axis activity had no relation with daily hassles or childhood life events. Cortisol concentrations were lower in patients with more previous episodes (p=.047), but not associated with recurrence(s) during follow-up. Finally, randomly assigned cognitive therapy at study-entry enhanced cortisol declines over the day throughout the two-year follow-up (p=.052).

CONCLUSIONS

Our results indicate that remitted recurrent MDD-patients have a persistent trait of increased cortisol concentrations, irrespective of stress. In combination with our finding that patients' cortisol concentrations do not change during new MDD-episodes (and thus not represent epiphenomenal or state-effects), our results support that hypercortisolemia fulfills the state-independence criterion for an endophenotype for recurrent depression.

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.

Depression in adolescence

Unipolar depressive disorder in adolescence is common worldwide but often unrecognised. The incidence, notably in girls, rises sharply after puberty and, by the end of adolescence, the 1 year prevalence rate exceeds 4%. The burden is highest in low-income and middle-income countries. Depression is associated with substantial present and future morbidity, and heightens suicide risk. The strongest risk factors for depression in adolescents are a family history of depression and exposure to psychosocial stress. Inherited risks, developmental factors, sex hormones, and psychosocial adversity interact to increase risk through hormonal factors and associated perturbed neural pathways. Although many similarities between depression in adolescence and depression in adulthood exist, in adolescents the use of antidepressants is of concern and opinions about clinical management are divided. Effective treatments are available, but choices are dependent on depression severity and available resources. Prevention strategies targeted at high-risk groups are promising.

The interaction of social risk factors and HPA axis dysregulation in predicting emotional symptoms of five- and six-year-old children

OBJECTIVE

We examined the links of social relational (family environment and peer victimization) and neuroendocrinological (HPA axis dysregulation) risk factors to children's emotional symptoms. We placed special emphasis on the joint effects of these risk factors with respect to the emergence and course of the emotional symptoms.

METHODS

One hundred and sixty-six children were interviewed (Berkeley Puppet Interview) at age 5 and 6. Teachers and parents completed the Strengths and Difficulties Questionnaire. Parents completed the Family Environment Scales. Peer victimization was assessed by teacher and child reports. Children's saliva cortisol was measured before and after a highly structured story completion task which targeted their cognitive emotional representations of family conflicts.

RESULTS

In the cross-sectional analyses, negative family environment, peer victimization, and cortisol increase during the story completion task independently contributed to the variance of emotional symptoms. There was a significant interaction effect between family environment and cortisol increase: those six-year-olds who had experienced an unfavorable family environment only showed high levels of emotional symptoms if they exhibited a cortisol increase during the story completion task. In the longitudinal analysis, peer victimization at age 5 predicted an increase of emotional symptoms at age 6, but only for those children who exhibited a blunted cortisol response a year earlier.

CONCLUSIONS

Negative family environment and peer victimization proved to be independently associated with emotional symptoms. HPA axis reactivity differentially moderated these associations. Therapeutic strategies should take the interaction between negative relational experiences and biological susceptibility to stress into account.

Childhood adversity and allostatic overload of the hypothalamic-pituitary-adrenal axis: a vulnerability model for depressive disorders

Childhood adversity is associated with increased risk for onset of depressive episodes. This review will present evidence that allostatic overload of the hypothalamic-pituitary-adrenal axis (HPAA) partially mediates this association. The HPAA is the physiological system that regulates levels of the stress hormone cortisol. First, data from animals and humans has shown that early environmental adversity is associated with long-term dysregulation of the HPAA. This may occur due to permanent epigenetic modification of the glucocorticoid receptor. Second, data from humans has demonstrated that HPAA dysregulation is associated with increased risk of future depression onset in healthy individuals, and pharmacological correction of HPAA dysregulation reduces depressive symptoms. HPAA dysregulation may result in corticoid-mediated abnormalities in neurogenesis in early life and/or neurotoxicity on neural systems that subserve emotion and cognition.

Overlapping neurobiology of learned helplessness and conditioned defeat: implications for PTSD and mood disorders

Exposure to traumatic events can increase the risk for major depressive disorder (MDD) as well as posttraumatic stress disorder (PTSD), and pharmacological treatments for these disorders often involve the modulation of serotonergic (5-HT) systems. Several behavioral paradigms in rodents produce changes in behavior that resemble symptoms of MDD and these behavioral changes are sensitive to antidepressant treatments. Here we review two animal models in which MDD-like behavioral changes are elicited by exposure to an acute traumatic event during adulthood, learned helplessness (LH) and conditioned defeat. In LH, exposure of rats to inescapable, but not escapable, tailshock produces a constellation of behavioral changes that include deficits in fight/flight responding and enhanced anxiety-like behavior. In conditioned defeat, exposure of Syrian hamsters to a social defeat by a more aggressive animal leads to a loss of territorial aggression and an increase in submissive and defensive behaviors in subsequent encounters with non-aggressive conspecifics. Investigations into the neural substrates that control LH and conditioned defeat revealed that increased 5-HT activity in the dorsal raphe nucleus (DRN) is critical for both models. Other key brain regions that regulate the acquisition and/or expression of behavior in these two paradigms include the basolateral amygdala (BLA), central nucleus of the amygdala (CeA) and bed nucleus of the stria terminalis (BNST). In this review, we compare and contrast the role of each of these neural structures in mediating LH and conditioned defeat, and discuss the relevance of these data in developing a better understanding of the mechanisms underlying trauma-related depression. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.

Frontal EEG asymmetry moderates the effects of stressful life events on internalizing symptoms in children at familial risk for depression

This study examined whether frontal alpha electroencephalographic (EEG) asymmetry moderates the association between stressful life events and depressive symptoms in children at familial risk for depression. Participants included 135 children ages 6 to 13, whose mothers had either a history of depression or no history of major psychiatric conditions. Frontal EEG was recorded while participants watched emotion-eliciting films. Symptoms and stressful life events were obtained via the Child Behavior Check List and a clinical interview, respectively. High-risk children displayed greater relative right lateral frontal activation (F7/F8) than their low-risk peers during the films. For high-risk children, greater relative left lateral frontal activation moderated the association between stressful life events and internalizing symptoms. Specifically, greater relative left lateral frontal activation mitigated the effects of stress in at-risk children.

Psychological and educational interventions for preventing depression in children and adolescents

BACKGROUND

Depression is common in young people, has a marked negative impact and is associated with self-harm and suicide. Preventing its onset would be an important advance in public health.  

OBJECTIVES

To determine whether psychological or educational interventions, or both, are effective in preventing the onset of depressive disorder in children and adolescents.

SEARCH METHODS

The Cochrane Depression, Anxiety and Neurosis Review Group's trials registers (CCDANCTR) were searched at the editorial base in July 2010. Update searches of MEDLINE, EMBASE, PsycINFO and ERIC were conducted by the authors in September 2009. Conference abstracts, reference lists of included studies and reviews were searched and experts in the field contacted.

SELECTION CRITERIA

Randomised controlled trials of psychological or educational prevention programmes, or both, compared with placebo, any comparison intervention, or no intervention for young people aged 5 to 19 years-old, who did not currently meet diagnostic criteria for depression or who were below the clinical range on standardised, validated, and reliable rating scales of depression, or both, were included.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion and rated their quality. Sample sizes were adjusted to take account of cluster designs and multiple comparisons. We contacted study authors for additional information where needed. 

MAIN RESULTS

Fifty-three studies including 14,406 participants were included in the analysis. There were only six studies with clear allocation concealment, participants and assessors were mostly not blind to the intervention or blinding was unclear so that the overall risk of bias was moderately high. Sixteen studies including 3240 participants reported outcomes on depressive diagnosis. The risk of having a depressive disorder post-intervention was reduced immediately compared with no intervention (15 studies; 3115 participants risk difference (RD) -0.09; 95% confidence interval (CI) -0.14 to -0.05; P<0.0003), at three to nine months (14 studies; 1842 participants; RD -0.11; 95% CI -0.16 to -0.06) and at 12 months (10 studies; 1750 participants; RD -0.06; 95% CI -0.11 to -0.01). There was no evidence for continued efficacy at 24 months (eight studies; 2084 participant; RD -0.01; 95% CI -0.04 to 0.03) but limited evidence of efficacy at 36 months (two studies; 464 participants; RD -0.10; 95% CI -0.19 to -0.02). There was significant heterogeneity in all these findings. There was no evidence of efficacy in the few studies that compared intervention with placebo or attention controls.

AUTHORS' CONCLUSIONS

There is some evidence from this review that targeted and universal depression prevention programmes may prevent the onset of depressive disorders compared with no intervention. However, allocation concealment is unclear in most studies, and there is heterogeneity in the findings. The persistence of findings suggests that this is real and not a placebo effect. 

Sensitivity to stress among the offspring of parents with bipolar disorder: a study of daytime cortisol levels

BACKGROUND

It is well known that the hypothalamic-pituitary-adrenal (HPA) axis is compromised in major depression and bipolar disorder. There is increasing evidence that subtle HPA abnormalities, such as elevated cortisol levels, precede the development of an affective disorder. Interpersonal stress is also associated with the development of affective disorders. The present study sought to determine whether interpersonal chronic and episodic stress moderated the relationship between cortisol levels in the natural environment and risk status, defined as having a parent with bipolar disorder.

METHOD

Sixty-two offspring of parents with bipolar disorder (OBD) and 60 offspring with no family history of affective disorders (OFH-), aged 19.48 years (s.d.=3.38, range 14-28), completed interviews assessing mental disorders and chronic and episodic stress, and provided saliva samples over 3 days.

RESULTS

Regression analyses revealed that the OBD who experienced high interpersonal chronic stress displayed a larger cortisol rise following awakening than the OBD reporting low interpersonal chronic stress. The same relationship was also found for levels of non-interpersonal chronic stress. The OBD who reported experiencing severe interpersonal episodic stress exhibited higher levels of daytime cortisol than the OBD reporting interpersonal episodic stress of mild severity. Importantly, none of the above relationships were detected in the OFH-. Each of the interactions between family history of affective disorders and stress remained after controlling for age, gender and offspring lifetime affective disorders and current non-affective disorders.

CONCLUSIONS

A biological sensitivity to stress may underlie the susceptibility to affective disorders among the OBD.

Adolescents' cortisol reactivity and subjective distress in response to family conflict: the moderating role of internalizing symptoms

PURPOSE

Internalizing symptoms have been associated with both higher and blunted cortisol responses in adolescents. Little attention has been paid to subjective experiences of distress in conjunction with internalizing symptoms in hypothalamic-pituitary-adrenal axis responses to laboratory stressors. The present study examines whether adolescents' internalizing symptoms moderate the association between cortisol responses and distress in response to a common stressor in adolescence: family conflict. Differences are also examined between adolescents with current, past only, and no history of internalizing symptoms.

METHODS

Adolescents (N = 70) discussed areas of conflict with their parents and subsequently reported on distress experienced during the discussion. Baseline and five poststressor saliva samples were collected. Adolescents' internalizing symptoms were assessed concurrently with the discussion and at three previous time-points.

RESULTS

Internalizing symptoms moderated the association between distress reported by the adolescents and cortisol reactivity in response to family conflict. Adolescents with current and past internalizing symptoms had a blunted cortisol response, whereas adolescents with no history of internalizing symptoms showed greater cortisol reactivity when reporting greater distress.

CONCLUSIONS

This study expands the understanding of how current and remitted internalizing symptoms are related to adolescents' responses to everyday family conflicts. Adolescents with current and past internalizing symptoms demonstrated a lack of correspondence between psychological and physiological stress, whereas adolescents with no history of internalizing symptoms showed the anticipated correspondence. This study has important implications for understanding the link between internalizing symptoms and adolescents' hypothalamic-pituitary-adrenal functioning in response to common social stressors.

Treatment-resistant depression in adolescents: is the addition of cognitive behavioral therapy of benefit?

Background

Many young people with major depression fail first-line treatments. Treatment-resistant depression has various definitions in the literature but typically assumes nonresponse to medication. In young people, cognitive behavioral therapy (CBT) is the recommended first-line intervention, thus the definition of treatment resistance should be expanded. Therefore, our aim was to synthesize the existing evidence of any interventions for treatment-resistant depression, broadly defined, in children and adolescents and to investigate the effectiveness of CBT in this context.

Methods

We used Cochrane Collaboration methodology, with electronic searches of Medline, PsycINFO, Embase, and the Cochrane Depression Anxiety and Neurosis Group trials registers. Only randomized controlled trials were included, and were assessed for risk of bias. Meta- analysis was undertaken where possible and appropriate.

Results

Of 953 articles retrieved, four trials were eligible for inclusion. For one study, only the trial registration document was available, because the study was never completed. All other studies were well conducted with a low risk of bias, although one study had a high dropout rate. Two studies assessed the effect of adding CBT to medication. While an assertive trial of antidepressants does appear to lead to benefit, when compared with placebo, there was no significant advantage, in either study, or in a meta-analysis of data from these trials, that clearly demonstrated an additional benefit of CBT. The third trial showed little advantage of a tricyclic antidepressant over placebo in the context of an inpatient admission.

Conclusion

Few randomized controlled trials have investigated interventions for treatment-resistant depression in young people, and results from these show modest benefit from antidepressants with no additional benefit over medication from CBT. Overall, there is a lack of evidence about effective interventions to treat young people who have failed to respond to evidence-based interventions for depression. Research in this area is urgently required.

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.

Age-related changes in plasma dehydroepiandrosterone levels in adults with Down's syndrome and the risk of dementia

People with Down's syndrome (DS) are at high risk of developing early onset dementia. Recent studies suggest a link between age-related decreases in dehydroepiandrosterone (DHEA) concentrations and dementia in the general population. The present study investigates the relationship between DHEA serum levels and age and the risk of dementia in adults with DS. The DHEA plasma concentrations of 67 adults with DS and 65 age-matched controls were determined. Participants with DS were assessed for the presence of dementia using the CAMDEX informant interview. The DHEA plasma concentrations decreased with age in subjects with DS as well as in controls. Age significantly predicted DHEA levels in both groups (B = -0.06, t = -4.536, P < 0.001 in the DS group and B = -0.04, t = -2.928, P < 0.005 in control participants). The mean ± SD DHEA level was 3.47 ± 1.41 μmol/l in controls and 2.79 ± 1.24 μmol/l in participants with DS. This difference was significant (t = -2.981, P < 0.01). Within the DS population, ancova revealed a significant relationship between DHEA concentrations and dementia (F(1,65) = 4.348, P < 0.05). We found that DHEA levels declined significantly with age in people with DS and controls and were lower, in comparison to age-matched controls, in people with DS across all ages studied. Those with DS and evidence of dementia have lower DHEA concentrations than those with DS (controlling for age) but without dementia.

Children suffering from separation anxiety disorder (SAD) show increased HPA axis activity compared to healthy controls

RESEARCH QUESTIONS

Separation anxiety disorder (SAD) is one of the most common mental disorders in childhood, and one of the earliest emerging. Little is known about the association between SAD and the hypothalamic-pituitary-adrenocortical (HPA) axis activity. Therefore, the present study aimed at investigating this association in children suffering from separation anxiety compared to healthy controls.

METHODS

A total of 31 children with diagnosed SAD (mean age: 8.45; 17 females, 14 males) and 25 healthy controls (HC; mean age: 9.74; 12 females, 13 males) took part in the study. All participants underwent psycho-physiological testing for HPA axis challenge. Testing consisted of a separation and a social exposure paradigm. Saliva samples to assess HPA axis-related cortisol secretion were gathered in parallel.

RESULTS

Compared to healthy controls, children with SAD showed greatly increased HPA axis activity, as reflected by an increased cortisol secretion throughout the entire period of investigation. The rise of cortisol was already observed in anticipation of, but not following the separation paradigm. No gender-related differences of cortisol secretion were observed.

CONCLUSIONS

Separation anxiety disorder (SAD) in children is reflected in greatly increased HPA axis activity. Compared to healthy controls, children with SAD showed increased cortisol values from the beginning of, and throughout, the entire investigation. This pattern of results suggests that both the anticipation of a separation and a persistent hyperactivity of the HPA axis system leads to an increased cortisol secretion.

Association of childhood adversities with the first onset of mental disorders in Japan: results from the World Mental Health Japan, 2002-2004

It is well known that childhood adversities (CAs) are a significant risk factor for mental disorders in later life. However, it is uncertain whether a similar association between CAs and mental disorders can be found in Japan. Few studies have employed an appropriate statistical model that takes into account the high comorbidity of CAs. The purpose of this study is to elucidate the association between CAs and the onset of mental disorders in Japan. We used the data from the World Mental Health Japan, 2002-2004 (n=1722). Respondents completed diagnostic interviews (the World Health Organization Composite International Diagnostic Interview) that assessed lifetime prevalence of 15 Diagnostic and Statistical Manual of Mental Disorders--Fourth Edition (DSM-IV) disorders. Associations of 12 retrospectively reported CAs with the lifetime prevalence of mental disorders were estimated using discrete-time survival analysis. Of the study sample, 32% reported as having experienced at least 1 CA during childhood. The studied CAs were highly comorbid. Parental mental illness showed significant sub-additive effects. The presence of 3 CAs showed a significant interactive effect on any mental health disorder. The number of CAs had a strong interactive effect on the onset of anxiety disorders. Predictive effects of CAs were found only among childhood onset mental disorders. It was confirmed that CAs are one of predictors of the onset of DSM-IV mental disorders, especially during childhood, in Japan.

The death(s) of close friends and family moderate genetic influences on symptoms of major depressive disorder in adolescents

BACKGROUND

Prior work has suggested that genetic influences on major depressive disorder (MDD) may be activated by the experience of negative life events. However, it is unclear whether these results persist when controlling for the possibility of confounding active gene-environment correlations (rGE).

METHOD

We examined a sample of 1230 adopted and biological siblings between the ages of 10 and 20 years from the Sibling Interaction and Behavior Study. MDD was measured via a lifetime DSM-IV symptom count. Number of deaths experienced served as our environmental risk experience. Because this variable is largely independent of the individual's choices/behaviors, we were able to examine gene-environment interactions while circumventing possible rGE confounds.

RESULTS

Biometric analyses revealed pronounced linear increases in the magnitude of genetic influences on symptoms of MDD with the number of deaths experienced, such that genetic influences were estimated to be near-zero for those who had experienced no deaths but were quite large in those who had experienced two or more deaths (i.e. accounting for roughly two-thirds of the phenotypic variance). By contrast, shared and non-shared environmental influences on symptoms of MDD were not meaningfully moderated by the number of deaths experienced.

CONCLUSIONS

Such results constructively replicate prior findings of genetic moderation of depressive symptoms by negative life events, thereby suggesting that this effect is not a function of active rGE confounds. Our findings are thus consistent with the notion that exposure to specific negative life events may serve to activate genetic risk for depression during adolescence.

Longitudinal study of stressful life events and daily stressors among adolescents at high risk for psychotic disorders

Psychosocial stress preceding the onset or recurrence of psychotic symptoms has been identified in patients with schizophrenia; yet there is limited understanding of the effects of stress in typically developing adolescents or those who show behavioral signs of risk for schizophrenia spectrum disorders. This study examined the developmental course of symptom progression as a function of stressful life events and daily hassles in adolescents with schizotypal personality disorder (SPD), other personality disorders, or no Axis II disorder. In this prospective longitudinal study, life events and daily stressors were assessed in adolescents aged 12 to 18 years. Results revealed that adolescents with SPD and other personality disorders reported significantly greater total, independent, and undesirable life events than individuals with no Axis II disorders. Youth with SPD report daily hassles to cause more distress compared to peers. Correlational analyses and hierarchal linear regression was used to evaluate the relationship of life events and daily stressors with psychiatric symptoms measured concurrently and 1 year later. Across diagnostic groups, the incidence of independent and undesirable life events were associated with current prodromal symptoms, while the frequency of daily stressors predicted a significant increment in positive, but not negative, prodromal symptoms over time. Therefore, adolescents who report greater daily stressors exhibit an increase in prodromal symptoms over a 1 year period. Psychosocial stress has been implicated in the etiology of schizophrenia, and these findings suggest the importance of life events and daily hassles as potential risk factors in the onset of psychotic symptoms during adolescence.

Individual differences in biological stress responses moderate the contribution of early peer victimization to subsequent depressive symptoms

RATIONALE

Some children who are exposed to early peer victimization become depressed, whereas others are resilient. Understanding individual differences in responses to early adversity, such as victimization, is critical for developing both comprehensive theoretical models and effective interventions.

OBJECTIVES

This study examined whether individual differences in biological stress responses (i.e., activation of the hypothalamic-pituitary-adrenal axis and autonomic nervous system) moderated the contribution of peer victimization to depressive symptoms across a 1-year period.

METHODS

Children (N = 132; M age = 9.46 years, SD = 0.33) completed measures of peer victimization and depressive symptoms, and rated their ruminative responses (i.e., persistent thoughts about negative task-related emotion and experiences) to a laboratory-based social challenge task involving two conflict-of-interests situations with an unfamiliar peer. Children's saliva was collected prior to, and following, participation in the task, and was later assayed for cortisol and alpha amylase [sAA].

RESULTS

Victimization interacted with levels of cortisol measured in anticipation of the task to predict task-related rumination and depressive symptoms 1 year later, adjusting for initial symptoms. Specifically, victimization served as a risk factor for rumination and depressive symptoms in children with heightened but not dampened anticipatory cortisol; yet, heightened anticipatory cortisol was protective against rumination and depressive symptoms in low-victimized children. Victimization also predicted subsequent depressive symptoms in girls with high sAA reactivity across the task.

CONCLUSIONS

This study advances contemporary theory and research by implicating individual variation in biological stress responses as one determinant of sensitivity to the mental health effects of early adversity.

Emotional memory in early steroid abnormalities: an FMRI study of adolescents with congenital adrenal hyperplasia

Hormonal imbalances during development may have long-lasting effects. Using functional magnetic resonance imaging (fMRI), we compared 14 youths with Congenital Adrenal Hyperplasia (CAH), a genetic disorder of hormonal dysfunction, with 22 healthy controls on memory encoding of emotional faces. Patients remembered fewer faces than controls, particularly fearful faces. FMRI data to successfully encoded fearful faces revealed that males with CAH showed significant activations in amygdala, hippocampus, and anterior cingulate relative to unaffected males, while females with CAH demonstrated deactivations relative to unaffected females in these regions. Findings indicate that steroid abnormalities during development can have important effects on neural correlates of emotional memory.

Psychological health throughout life and adult cortisol patterns at age 45 y

Population-based studies of cortisol and psychological health over long periods are rare. This study aims to establish whether cortisol levels in mid-adulthood are associated with chronicity and life-stage of psychological ill-health onset. We used data from the 1958 British birth cohort (3209 males; 3315 females) with cortisol measures 45 min post-waking (t1) and 3h later (t2) on the same day at 45y. Lifetime psychological health was identified from child and adult measures (ages 7, 11, 16, 23, 33, 42, 45y). t1 cortisol was lower by 3-4% in those with lifetime (child and adult) ill-health than those with no ill-health, after adjustment for socio-economic position and smoking. t1 cortisol was similarly lowered in those with adult onset of ill-health, but not among the group whose ill-health was of recent onset. t2 cortisol was elevated among all lifetime ill-health groups, by 6-9%, except for those whose ill-health did not extend beyond childhood. Simple analyses across the separate ages of follow-up suggest that elevations in t2 cortisol reflect associations for adult ill-health. Our study suggests that psychological ill-health over years and decades "blunts" post-awakening cortisol secretion, possibly reflecting HPA dysregulation due to social stressors.

Disentangling psychobiological mechanisms underlying internalizing and externalizing behaviors in youth: longitudinal and concurrent associations with cortisol

Research examining cortisol dysregulation is seemingly contradictory with studies showing that both internalizing and externalizing behaviors are related to high and low cortisol. One extant theory to explain divergent findings in the stress literature is that both hypo- and hyper-arousal of the hypothalamic-pituitary-adrenal (HPA) axis may be present depending on time since onset of the stressor. This theory may extend to the onset of internalizing and externalizing behaviors. Data from 96 youth participating in a longitudinal project were used to examine this possibility. Composite measures of internalizing and externalizing behaviors at both childhood and early adolescence were formed using mother and teacher reports. Multiple salivary cortisol samples were also collected over two consecutive days during early adolescence. Problematic behaviors were associated with cortisol and the direction of the association was dependent on amount of time passed since onset of the behaviors. When examined concurrently in adolescence, youth with more internalizing behaviors had higher morning cortisol; however, when examined longitudinally, youth with more internalizing behaviors in childhood had lower morning cortisol levels as adolescents. Youth with more externalizing behaviors in childhood had flattened diurnal cortisol rhythms as adolescents, and this finding persisted when examined in adolescence. Cortisol dysregulation was greatest in children with the most severe behavior problems. Findings support the theoretical model of blunting of the HPA axis over time. While the HPA axis may show hyper-arousal when youth first display behaviors, long-term exposure may lead to a hypo-arousal of the HPA axis which culminates in a dysregulated diurnal rhythm.

The hypothalamic-pituitary-adrenal axis and serotonin abnormalities: a selective overview for the implications of suicide prevention

Suicidal behavior and mood disorders are one of the world's largest public health problems. The biological vulnerability for these problems includes genetic factors involved in the regulation of the serotonergic system and stress system. The hypothalamic-pituitary-adrenal (HPA) axis is a neuroendocrine system that regulates the body's response to stress and has complex interactions with brain serotonergic, noradrenergic and dopaminergic systems. Corticotropin-releasing hormone and vasopressin act synergistically to stimulate the secretion of ACTH that stimulates the biosynthesis of corticosteroids such as cortisol from cholesterol. Cortisol is a major stress hormone and has effects on many tissues, including on mineralocorticoid receptors and glucocorticoid receptors in the brain. Glucocorticoids produce behavioral changes, and one important target of glucocorticoids is the hypothalamus, which is a major controlling center of the HPA axis. Stress plays a major role in the various pathophysiological processes associated with mood disorders and suicidal behavior. Serotonergic dysfunction is a well-established substrate for mood disorders and suicidal behavior. Corticosteroids may play an important role in the relationship between stress, mood changes and perhaps suicidal behavior by interacting with 5-HT1A receptors. Abnormalities in the HPA axis in response to increased levels of stress are found to be associated with a dysregulation in the serotonergic system, both in subjects with mood disorders and those who engage in suicidal behavior. HPA over-activity may be a good predictor of mood disorders and perhaps suicidal behavior via abnormalities in the serotonergic system.

Polymorphisms in BDNF (Val66Met) and 5-HTTLPR, morning cortisol and subsequent depression in at-risk adolescents

BACKGROUND

There is increasing evidence for genetic effects on the hypothalamic-pituitary axis system. More than one gene is likely to moderate corticoid-mediated activity.

AIMS

To investigate whether the brain-derived neurotrophic factor (BDNF) polymorphism (rs6265, Val66Met) is associated with morning waking salivary cortisol and moderates the corticoid-mediated risk for subsequent depressive episode onset independently of the known effects of 5-HTTLPR (the serotonin transporter gene promoter).

METHOD

High-risk adolescents (n = 401) were genotyped for Val66Met BDNF and 5-HTTLPR. Salivary samples were obtained on four consecutive school days within 1 h of waking. There were 365 (91%) remaining participants reassessed at 12 months for episodes of psychiatric disorder in the follow-up period. Of these, 357 (89%) had complete data for multivariate modelling.

RESULTS

There were 41 (11.2%) individuals who reported a new episode of clinical depression over the follow-up period. Increased risk for subsequent depression was found in carriers of the Val66Val genotype in BDNF with higher morning waking cortisol. This remained present when the known interaction between carriers of a short allele of 5-HTTLPR with higher morning salivary cortisol was taken into account.

CONCLUSIONS

Both BDNF and 5-HTTLPR genes show evidence of modifying the risk of a subsequent new depressive episode associated with elevated morning salivary cortisol. In adolescents morning salivary cortisol levels may constitute a biomarker for some forms of unipolar depression.

Sensitivity to the depressogenic effect of stress and HPA-axis reactivity in adolescence: a review of gender differences

Adolescence is characterized by major biological, psychological, and social challenges, as well as by an increase in depression rates. This review focuses on the association between stressful experiences and depression in adolescence, and the possible role of the hypothalamus-pituitary-adrenal cortex (HPA-)axis in this link. Adolescent girls have a higher probability to develop depressive symptoms than adolescent boys and preadolescents. Increasing evidence indicates that girls' higher risk of depression is partly brought about by an increased sensitivity for stressful life events, particularly interpersonal stressors, which are highly prevalent in adolescent girls. Genetic risk factors for depression, as well as those for stress sensitivity, are often expressed differently in girls and boys. Also environmental adversity tends to affect girls' stress responses more than those of boys. These gender-specific association patterns have been reported for both sensitivity to stressful life events and HPA-axis responses to social stress. Together, the findings suggest that girls are more malleable than boys in response to internal and external influences. This postulated greater malleability may be adaptive in many circumstances, but also brings along risk, such as an increased probability of depression.

Behavioral adjustment in a community sample of boys: links with basal and stress-induced salivary cortisol concentrations

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been observed in association with internalizing symptoms and is thought to be involved in the pathogenesis of depression and some anxiety disorders. This study examined basal and stress-induced cortisol concentrations in relation to internalizing and externalizing symptoms in a racially mixed community sample of 102 8-11-year-old boys. Afternoon basal cortisol concentrations were positively correlated with measures of internalizing behavior problems, social problems, and emotionality. Greater change in cortisol across a home-visit challenge task was also significantly associated with internalizing behaviors and social problems, as well as attention and thought problems. The implications of these findings and how they may relate to the pathogenesis of emotional and behavioral problems are discussed.

Early and late life events and salivary cortisol in older persons

BACKGROUND

It has been hypothesized that stressful life events are associated with changes in hypothalamic-pituitary-adrenal (HPA) axis regulation, which increases susceptibility to psychiatric disorders. We investigated the association of early and late life events with HPA axis regulation in older persons.

METHOD

Within the Longitudinal Aging Study Amsterdam (LASA) 1055 participants (47% male), aged 63-93 years, collected saliva within 30 min after waking and late in the evening. Early and late life events were assessed during a home interview. The associations between life events and cortisol levels were examined using linear regression and analysis of covariance with adjustments for demographics, cardiovascular risk factors and depressive symptoms.

RESULTS

Within our sample, the median morning and evening cortisol levels were 15.0 nmol/l [interdecile range (10-90%): 7.4-27.0 nmol/l] and 2.8 nmol/l (10-90%: 1.5-6.3 nmol/l), respectively. Persons who reported early life events showed lower levels of natural log-transformed morning cortisol [B=-0.10, 95% confidence interval (CI) -0.17 to -0.04] and flattened diurnal variability of cortisol (B=-1.06, 95% CI -2.05 to -0.08). Those reporting two or more late life events showed higher levels of natural log-transformed morning cortisol (B=0.10, 95% CI 0.02-0.18) and higher diurnal variability (B=1.19, 95% CI 0.05-2.33). No associations were found with evening cortisol.

CONCLUSIONS

The results of this large population-based study of older persons suggest a differential association of early and late life events with HPA axis regulation; early life events were associated with a relative hypo-secretion of morning cortisol and flattened diurnal variability, while late life events were associated with elevated secretion of morning cortisol and high diurnal variability of cortisol.

Glucagon-like peptide-1 receptor gene polymorphism (Leu260Phe) is associated with morning cortisol in preschoolers

Glucagon-like peptide-1 (GLP-1) has been shown to be a potent stress-regulating neuropeptide in animal models, but little is known about whether genetic polymorphisms that influence this peptide influence stress responses in humans. We therefore explored whether a missense mutation (rs1042044) in the GLP-1 receptor was associated with morning and evening salivary cortisol levels in preschool aged children. Morning and evening saliva samples and individual buccal swabs for DNA extraction were collected from seventy-seven preschool aged children. Salivary cortisol was assayed using a time-resolved fluorescence immunoassay with fluorometric end-point detection (DELFIA), and the rs1042044 single nucleotide polymorphism (SNP) was genotyped using allele specific TaqMan probes. Children homozygous for the phenylalanine (C) substitution in the GLP-1R gene had significantly higher morning salivary cortisol levels than children with other GLP-1R genotypes (p=0.029). Additionally, children with one or two copies of the phenylalanine (C) allele had significantly higher morning cortisol levels compared to children homozygous for the leucine (A) allele (p=0.008). Our results identify associations between a novel genetic variant of GLP-1R and hypothalamus-pituitary-adrenal (HPA) axis regulation. This polymorphism may have functional significance in stress-related psychiatric disorders.

Prospective prediction of major depressive disorder from cortisol awakening responses in adolescence

Levels of the stress-sensitive hormone cortisol increase dramatically in the first 30-40min after waking, an effect known as the cortisol awakening response (CAR). There is considerable cross-sectional evidence that psychosocial stress is associated with an increased CAR, and the CAR has been found to be altered in the presence of stress-related diseases, including major depressive disorder (MDD). To date, no prospective longitudinal studies have examined whether individual differences in the CAR serve as a premorbid risk factor for MDD. In a sample of 230 late adolescents, clinical diagnoses of MDD were predicted from the CAR as well as other indicators of basal cortisol functioning gathered 1 year earlier, including: waking cortisol levels, bedtime cortisol levels, the size of the CAR, average cortisol, and the slope of the diurnal cortisol rhythm across the waking day. Age and gender, health and health behaviors, baseline neuroticism, exposure to stressful life events and past episodes of mood and anxiety disorders were included as covariates, to help ensure effects are attributable to the CAR rather than related variables. A higher baseline CAR was associated with a significantly increased risk of developing MDD by follow-up, even when excluding individuals with baseline MDD. No other baseline cortisol measures were significant prospective predictors of MDD. In summary, the CAR is a significant prospective risk factor for the development of MDD in young adults, providing some support for the possibility that a heightened CAR may play a role in the etiology of major depressive disorder.

High susceptibility to chronic social stress is associated with a depression-like phenotype

Chronic stress is a key risk factor for a variety of diseases, including depression. There is a large degree of individual variation in the ability to recover successfully from a chronic stress exposure, but the determinants of this individual stress susceptibility are still poorly understood. We recently developed a novel mouse paradigm for chronic social stress during adolescence, which closely mimics the human condition of chronic social stress in respect to construct, face and predictive validity. By applying this chronic stress model to a large number of animals we aimed at identifying individuals that are either resilient or vulnerable to the persistent effects of chronic social stress exposure. Animals showing markedly elevated basal corticosterone levels 5 weeks following the end of the stress paradigm were considered "vulnerable", whereas individuals recovering quickly and being indistinguishable from controls were classified as "resilient". Stress vulnerability was associated with an increased level of corticotropin-releasing hormone in the paraventricular nucleus, decreased hippocampal mineralocorticoid receptor expression as well as increased anxiety- and depression-like behavior compared to resilient and control animals. In summary, we show that by using a large cohort of animals it is possible to select individuals that are vulnerable or resilient to the lasting effects of chronic social stress. The vulnerable phenotype mimics many aspects of stress-related human affective disorders and this may be used as a novel approach to study depression in an animal model, ultimately contributing to a better understanding and treatment of stress-related disorders.

Disturbances in early parenting of depressed mothers and cortisol secretion in offspring: a preliminary study

BACKGROUND

Disturbances in cortisol secretion are associated with risk for psychiatric disorder, including depression. Animal research indicates that early care experiences influence hypothalamic-pituitary-adrenal (HPA) axis functioning in offspring. Similar effects are suggested in human development, but evidence of longitudinal associations between observed early parenting and offspring cortisol secretion is extremely limited. We studied associations between parenting disturbances occurring in the context of maternal postnatal depression (PND), and elevations in morning cortisol secretion in the adolescent offspring of PND mothers.

METHODS

We observed maternal parenting behaviour on four occasions through the first year and at five-year follow-up in postnatally depressed (n=29) and well (n=20) mothers. Observations were coded for maternal sensitivity and withdrawn behaviour. Basal offspring salivary cortisol secretion was measured at 13-years, using collections over 10-days.

RESULTS

Postnatal, but not five-year, maternal withdrawal predicted elevated mean and maximum morning cortisol secretion in 13-year-old offspring. There were no significant associations between maternal sensitivity and offspring cortisol secretion.

LIMITATIONS

The sample size was relatively small, and effects tended to be reduced to trend level when covariates were considered. The correlational nature of the study (albeit longitudinal) limits conclusions regarding causality.

CONCLUSIONS

Individual differences in early maternal parenting behaviour may influence offspring cortisol secretion, and thereby risk for depression. Parenting interventions that facilitate active maternal engagement with the infant may be indicated for high-risk populations.

Prodromal symptoms and atypical affectivity as predictors of major depression in juveniles: implications for prevention

BACKGROUND

Given the long-term morbidity of juvenile-onset major depressive disorder (MDD), it is timely to consider whether more effort should be dedicated to its primary and secondary prevention.

METHODS

We reviewed studies of prodromal symptoms that may herald a first episode pediatric MDD and considered whether that literature has made an impact on secondary prevention (efforts to prevent progression from symptoms to full disorder). We also reviewed studies of children at familial risk for MDD that addressed atypical affectivity and the regulation of sad, dysphoric affect (mood repair) and related physiological systems, and considered whether research in those areas has made an impact on primary prevention of pediatric MDD (efforts to prevent the disorder).

RESULTS

A compelling body of literature indicates that depressive symptoms in youngsters predict subsequent MDD across the juvenile (and early adult) years and that any combination of several symptoms for at least one week is informative in that regard. These findings are echoed in the case selection criteria used by many secondary prevention programs. Convergent findings also indicate that (compared to typical peers) young offspring at familial risk for depression manifest low positive affectivity and compromised mood repair, along with signs of dysfunction in three intertwined physiological systems that contribute to affectivity and mood repair (the hypothalamic-pituitary-adrenal (HPA) axis, cerebral hemispheric asymmetry, and cardiac vagal control). While all these affect-related parameters are suitable for case selection and as intervention targets, they have not yet made an impact on primary prevention programs.

CONCLUSIONS

According to recent meta-analyses, attempts to prevent pediatric depression have not lived up to expectations. Based on our review, possible reasons for this include: (a) the use of case selection criteria that yield samples heterogeneous with regard to whether the symptoms are truly prodromal to an episode of MDD or are trait-like (which could affect response to the intervention), (b) failure to fully capitalize on the broad-ranging literature on vulnerability to pediatric MDD, as evidenced by the infrequent use of family history of depression (a robust index of vulnerability) or combined indices of vulnerability for case selection, and (c) lack of synchrony between dimensions of vulnerability and the content of the prevention program, as indicated by the overwhelming use of cognitive-behavioral interventions, irrespective of subjects' age, developmental readiness, and whether or not they evidenced the relevant cognitive vulnerability. Prevention trials of pediatric MDD could benefit from new approaches to case selection that combine various indices of vulnerability, more effective use of existing findings, and new or modified interventions that are developmentally sensitive.

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.