Serotonin transporter genotype, morning cortisol and subsequent depression in adolescents

Three-variable systems: An integrative moderation and mediation framework for developmental psychopathology

In this article, we consider an often overlooked model that combines mediation and moderation to explain how a third variable can relate to a risk factor-psychopathology relationship. We refer to it as moderation and mediation in a three-variable system. We describe how this model is relevant to studying vulnerability factors and how it may advance developmental psychopathology research. To illustrate the value of this approach, we provide several examples where this model may be applicable, such as the relationships among parental externalizing pathology, harsh parenting, and offspring psychopathology as well as between neuroticism, stressful life events, and depression. We discuss possible reasons why this model has not gained traction and attempt to clarify and dispel those concerns. We provide guidance and recommendations for when to consider this model for a given data set and point toward existing resources for testing this model that have been developed by statisticians and other methodologists. Lastly, we describe important caveats, limitations, and considerations for making this approach most useful for developmental research. Overall, our goal in presenting this information to developmental psychopathology researchers is to encourage testing moderation and mediation in a three-variable system with the aim of advancing analytic strategies for studying vulnerability factors.

Prediction model and case analysis of college students' psychological depression based on multi-source online comment mining

Psychological depression is a normal emotional experience of human beings. Everyone will experience different levels of depression in life. Under the dual influence of the current socio-economic environment and the small environment of students' quality, the depressive tendency of college students cannot be ignored. In order to mine and improve the level of College Students' psychological depression, this paper proposes a prediction model of College Students' PD based on multi-source online comment mining. The data mining method is used to analyze the content and emotion of microblog comments of users with depressive tendencies. Then, pattern extraction and matching are used to find low-frequency feature words. The example analysis shows that when the comment length is set to 10 and the news length is set to 47, the classification accuracy of the test set is the highest, reaching 96.454%, higher than the original 94.898%. Learning pressure, economic pressure, employment pressure, coping style and social support are closely related to depression and anxiety. Therefore, when modeling depression and anxiety, they were selected as predictive properties. The PD prediction model of college students based on multi-source online comment mining has achieved good results in the polarity classification of online comments.

The ratio of morning cortisol to CRP prospectively predicts first-onset depression in at-risk adolescents

RATIONALE

Early-onset adolescent depression is related to poor prognosis and a range of psychiatric and medical comorbidities later in life, making the identification of a priori risk factors for depression highly important. Increasingly, dysregulated levels of immune and neuroendocrine markers, such as C-reactive protein (CRP) and cortisol, have been demonstrated as both precursors to and consequences of depression. However, longitudinal research with adolescent populations is limited and demonstrates mixed immuno-endocrine-depression links.

OBJECTIVE

This study explored the putative bidirectional relationship between salivary measures of cortisol (Cort) and CRP, including the novel Cort:CRP ratio and depression.

METHODS

Participants from the randomized control trial 'Sleep and Education: learning New Skills Early' (SENSE) Study were 122 adolescents at risk for depression (73 females) aged 12-16 years (M = 12.71 years, SD = 1.01 years) assessed at baseline (T1), post-intervention (T2), and a two-year follow-up (T3).

RESULTS

Logistic regression results demonstrated that adolescents with higher T1 Cort:CRP_morn ratio levels were two-fold more likely to develop a first-onset depressive disorder from T2 to T3 as compared to adolescents with lower Cort:CRP_morn ratio levels, β = 0.73, t (36) = 2.15, p = .04, OR = 2.08. This effect was not moderated by treatment condition (β = -1.38, t (13) = -1.33, p = .20) and did not change when controlling for known risk factors for depression, including sex, age, body-mass index, socio-economic status, T1 anxiety disorder, nor T1 sleep disturbance, anxiety, or depressive symptoms (β = 0.91, t (31) = 2.14, p = .04).

CONCLUSION

Results highlight potential immuno-endocrine dysregulation as an underlying risk factor for adolescent first-onset depression, and may inform the development of targeted, preventative biobehavioral treatment strategies for youth depression.

Identifying diurnal cortisol profiles among young adults: Physiological signatures of mental health trajectories

Previous research has used cortisol, the major hormonal byproduct of the hypothalamic pituitary adrenal (HPA) axis system, to explore how environmental stressors influence daily physiological functioning. Most of the research focused on diurnal cortisol has examined specific cortisol markers, with little consideration of how different components of the diurnal pattern may co-occur. Morning level, cortisol awakening response (CAR), bedtime level, as well as the diurnal slope and total cortisol exposure throughout the day (area under the curve; AUC), are five common parameters of diurnal HPA axis functioning that have been individually linked to physical and mental health outcomes, with mixed results. The current study introduces a novel approach to capture heterogeneity in HPA axis activity by using latent profile analysis to generate empirically-derived, theoretically supported diurnal cortisol profiles based on all five indicators. We analyzed salivary cortisol data from 278 young adults during a time of heightened sociopolitical stress - the 2016 U.S. presidential election - and examined whether profiles differentially predicted mental health trajectories across six months. Findings suggest that a specific combination of cortisol parameters (i.e., flat slope, high AUC, and high CAR) may predict worse mental health risk over time. Overall, this work suggests that diurnal cortisol profiles likely reflect distinct physiological underpinnings with unique health consequences that may not be observed by studying individual cortisol parameters.

Early life stress and HPA axis function independently predict adult depressive symptoms in metropolitan Cebu, Philippines

OBJECTIVES

Alterations in adult hypothalamic-pituitary-adrenal (HPA) axis activity have increasingly been linked with early life stress and adult depression, but a limited number of studies have used longitudinal data to explore HPA axis dysregulation as an underlying mechanism driving the long-term depressive impacts of early stressors. Here we address potential long-term impacts of early life, family-based stress on depressive symptoms among young adults in a longitudinal birth cohort study begun in 1983 in the Philippines.

MATERIALS AND METHODS

We relate a composite measure of family-based stressors experienced between birth and adolescence to circadian dynamics in adult salivary cortisol and depressive risk measured at 21-22 years of age. Multiple regression analyses were conducted to examine the relationship between early life stress levels and risk of adult depressive symptoms, as well as the role of adult diurnal cortisol activity in this relationship.

RESULTS

Greater levels of early life familial stress predicted more severe depressive symptomatology at age 21-22 in a dose-response fashion (p < .0001) independent of adult diurnal cortisol patterns. Flatter diurnal cortisol slopes are directly associated with higher adult depressive symptoms, an effect mostly driven by evening cortisol levels (p = .004). When considering the cumulative effects of early life stress measures, however, exposure to more of these stressors during development is associated with even higher depressive symptoms.

DISCUSSION

The long-term depressive effects of early life familial stress extend to this large sample of Cebuano young adults, and early life stress and HPA axis function may shape adult depressive symptoms through independent pathways in this sample. Our findings provide further evidence that HPA axis activity is shaped by early life conditions and is associated with depressive symptoms.

Attachment impacts cortisol awakening response in chronically depressed individuals

BACKGROUND

Early life experiences shape individual attachment, creating a template for regulating emotions in interpersonal situations, likely to persist across the lifespan. Research has shown that individual attachment creates vulnerability for depression, and also impacts the Hypothalamic-Pituitary-Adrenal (HPA) axis. Still, the relationship between attachment and the HPA axis in depressed individuals is unclear. Cortisol awakening response (CAR) has been recently investigated as a possibly useful physiological marker related to attachment insecurity and depression risk. However, research exploring the relationship between the CAR and attachment in individuals with chronic depression in either the presence or the absence of comorbid anxiety is lacking. The purpose of the current study was to fill this gap, by comparing the CAR in individuals with chronic depression with/without comorbid anxieties and controls. In addition, we also wanted to explore the relationship between attachment and the CAR in this group and to explore their predictive role for later depression severity.

METHODS

Individuals experiencing a current depressive episode at least six months in length (cMDD; n = 63) and healthy controls (HC; n = 57) were enrolled in the study (total n = 120). Participants completed a structured clinical diagnostic interview (SCID-I) as well as measures of depression severity (Beck Depression Inventory-II (BDI-II) and Hamilton Rating Scale for Depression) and attachment dimensions (Experiences in Close Relationships scale; ECR) at baseline. In addition, participants provided salivary samples at four time points (i.e. 0 (S1), 30, 45 and 60 min) following awakening on two consecutive days. S1 cortisol, the area under the curve with respect to ground (AUCg) and increase (AUCi) were calculated based on the average values across both days. The HC and cMDD groups were compared on all measures. The CAR for individuals with cMDD alone (n = 14) and individuals with cMDD with two or more comorbid anxiety disorders (cMDD ≥ 2Anx; n = 30) were also compared. A subset of participants (n = 59) agreed to return for follow up one year later. Participants returning for follow up repeated the BDI-II and ECR. No salivary samples were collected at follow-up.

RESULTS

The cMDD group had significantly lower S1 cortisol and AUCg compared to the HC group (both p ≤ 0.02). cMDD and cMDD ≥ 2Anx groups did not differ in their CAR. Regression analyses revealed that depression severity and the attachment interaction term was associated with lower S1 and AUCg cortisol (p < 0.01). Greater attachment avoidance was positively associated with S1 cortisol (p = 0.02), while mean awakening time on sample days was negatively associated with S1 cortisol. We also found a significant interaction between the attachment dimensions such that at low levels of attachment anxiety, attachment avoidance had a positive relationship with S1 cortisol and AUCg. The opposite relationship existed when attachment anxiety was high. Higher baseline BDI-II score and higher baseline attachment anxiety were predictive of higher scores on the BDI-II one-year later (both p < 0.05).

CONCLUSIONS

The current findings bring evidence that depression severity is associated with blunting of the CAR irrespective of the comorbid status with anxiety disorders. In addition, attachment avoidance may protect against the CAR blunting in individuals with low attachment anxiety. However, individuals with high attachment anxiety and avoidance might have additional CAR blunting. Attachment anxiety might be a good predictor of future depression severity.

Prospective biomarkers of major depressive disorder: a systematic review and meta-analysis

Leading biological hypotheses propose that biological changes may underlie major depressive disorder onset and relapse/recurrence. Here, we investigate if there is prospective evidence for biomarkers derived from leading theories. We focus on neuroimaging, gastrointestinal factors, immunology, neurotrophic factors, neurotransmitters, hormones, and oxidative stress. Searches were performed in Pubmed, Embase and PsychInfo for articles published up to 06/2019. References and citations of included articles were screened to identify additional articles. Inclusion criteria were having an MDD diagnosis as outcome, a biomarker as predictor, and prospective design search terms were formulated accordingly. PRISMA guidelines were applied. Meta-analyses were performed using a random effect model when three or more comparable studies were identified, using a random effect model. Our search resulted in 67,464 articles, of which 75 prospective articles were identified on: Neuroimaging (N = 24), Gastrointestinal factors (N = 1), Immunology (N = 8), Neurotrophic (N = 2), Neurotransmitters (N = 1), Hormones (N = 39), Oxidative stress (N = 1). Meta-analyses on brain volumes and immunology markers were not significant. Only cortisol (N = 19, OR = 1.294, p = 0.024) showed a predictive effect on onset/relapse/recurrence of MDD, but not on time until MDD onset/relapse/recurrence. However, this effect disappeared when studies including participants with a baseline clinical diagnosis were removed from the analyses. Other studies were too heterogeneous to compare. Thus, there is a lack of evidence for leading biological theories for onset and maintenance of depression. Only cortisol was identified as potential predictor for MDD, but results are influenced by the disease state. High-quality (prospective) studies on MDD are needed to disentangle the etiology and maintenance of MDD.

Pharmacological manipulations of judgement bias: A systematic review and meta-analysis

Validated measures of animal affect are crucial to research spanning numerous disciplines. Judgement bias, which assesses decision-making under ambiguity, is a promising measure of animal affect. One way of validating this measure is to administer drugs with affect-altering properties in humans to non-human animals and determine whether the predicted judgement biases are observed. We conducted a systematic review and meta-analysis using data from 20 published research articles that use this approach, from which 557 effect sizes were extracted. Pharmacological manipulations overall altered judgement bias at the probe cues as predicted. However, there were several moderating factors including the neurobiological target of the drug, whether the drug induced a relatively positive or negative affective state in humans, dosage, and the presented cue. This may partially reflect interference from adverse effects of the drug which should be considered when interpreting results. Thus, the overall pattern of change in animal judgement bias appears to reflect the affect-altering properties of drugs in humans, and hence may be a valuable measure of animal affective valence.

Cortisol awakening response and additive serotonergic genetic risk interactively predict depression in two samples: The 2019 Donald F. Klein Early Career Investigator Award Paper

BACKGROUND

The serotonin system and hypothalamic pituitary-adrenal (HPA)-axis are each implicated in the pathway to depression; human and animal research support these systems' cross-talk. Our work implicates a 5-variant additive serotoninergic multilocus genetic profile score (MGPS) and separately the cortisol awakening response (CAR) in the prospective prediction of depression; other work has shown that the serotonin transporter polymorphism 5HTTLPR predicts CAR and interacts with the CAR to predict depression.

METHODS

We tested the hypothesis that a 6-variant MGPS (original plus 5HTTLPR) would interact with CAR to predict prospective depressive episode onsets in 201 emerging adults using four annual follow-up interviews. We also tested whether MGPS predicted CAR. We attempted replication of significant findings in a sample of 77 early adolescents predicting depression symptoms.

RESULTS

In sample 1, MGPS did not significantly predict CAR. MGPS interacted with CAR to predict depressive episodes; CAR slopes for depression steepened as MGPS increased, for risk or protection. No single variant accounted for results, though CAR's interactions with 5HTTLPR and the original MGPS were both significant. In sample 2, the 6-variant MGPS significantly interacted with CAR to predict depression symptoms.

CONCLUSIONS

Higher serotonergic MGPS appears to sensitize individuals to CAR level-for better and worse-in predicting depression.

At-risk studies and clinical antecedents of psychosis, bipolar disorder and depression: a scoping review in the context of clinical staging

Identifying young people at risk of developing serious mental illness and identifying predictors of onset of illness has been a focus of psychiatric prediction research, particularly in the field of psychosis. Work in this area has facilitated the adoption of the clinical staging model of early clinical phenotypes, ranging from at-risk mental states to chronic and severe mental illness. It has been a topic of debate if these staging models should be conceptualised as disorder-specific or transdiagnostic. In order to inform this debate and facilitate cross-diagnostic discourse, the present scoping review provides a broad overview of the body of literature of (a) longitudinal at-risk approaches and (b) identified antecedents of (homotypic) illness progression across three major mental disorders [psychosis, bipolar disorder (BD) and depression], and places these in the context of clinical staging. Stage 0 at-risk conceptualisations (i.e. familial high-risk approaches) were identified in all three disorders. However, formalised stage 1b conceptualisations (i.e. ultra-high-risk approaches) were only present in psychosis and marginally in BD. The presence of non-specific and overlapping antecedents in the three disorders may support a general staging model, at least in the early stages of severe psychotic or mood disorders.

Kinds of individuals defined by patterns of variables

This paper argues that investigators should consider replacing the popular practice of comparing individuals varying in gender, social class, and/or ethnicity on one or more continuous measures with a search for kinds of individuals defined by patterns of properties that include not only their values on outcome measures but also their gender, social class, and ethnicity. Investigators who believe that a particular predictor contributes to an outcome independent of the gender, class, or ethnicity of the participants often implement statistical procedures that promise to remove the contributions of the above categories. These analyses lead to misleading conclusions when the controlled category is correlated with the dependent measures. The final sections summarize the properties of genders, classes, and ethnic groups that make distinctive contributions to many psychological outcomes. The paper ends by noting that a society's ethical beliefs constitute a defensible basis for ignoring the biological properties associated with these categories in order to allow members of these groups access to whatever educational or occupational goals they desire.

Childhood adversity moderates the influence of proximal episodic stress on the cortisol awakening response and depressive symptoms in adolescents

Childhood adversity (CA) is known to predict sensitization to proximal stressors. Researchers have suggested that disruptions in hypothalamus-pituitary-adrenal axis functioning may be a biological mechanism. If so, CA may predict altered associations between proximal life stress and markers of cortisol secretion. We examined whether CA moderates associations between recent episodic stress and (a) the cortisol awakening response (CAR), and (b) depressive symptoms, in 241 adolescents aged 14-17 years (cortisol n = 196). Salivary cortisol was sampled at 0, 30, and 60 min postawakening for 2 days. The CAR was calculated as the area under the curve with respect to increase and waking cortisol. CA and episodic stress were assessed using contextual-threat-method-coded objective interviews. CA significantly interacted with episodic stress to predict both the CAR and depression. Among those with low CA, episodic stress predicted increased CAR but did not predict depression. For adolescents with high CA, episodic stress predicted lower CAR and higher depression. These interactions were found only for independent (uncontrollable, fateful) events, and not for dependent (self-generated) stress. Increased allostatic load resulting from CA exposure may interfere with adolescents' ability to optimally regulate their CAR in relation to recent stress, contributing to increased depression risk.

Sex differences in the association between internalizing symptoms and hair cortisol level among 10-12 year-old adolescents in China

Although numerous studies have described the relationship between HPA axis dysregulation and internalizing symptoms among adolescents, research using hair cortisol concentrations in pre- and young adolescent samples has not been reported. We investigated the association of self-reported internalizing symptoms with cortisol concertration in hair among pre- and young adolescents aged 10–12 years. Forty-six boys and 39 girls supplied a hair sample of at least 3 cm in length for an analysis of this period (3 months) cortisol excretion. Saliva cortisol reactivity to the Trier Social Stress Test for Children (TSST-C) also was assessed. The study found a positive association between ratings of depressive symptoms and cumulative levels of hair cortisol only in boys. Furthermore, higher ratings of anxiety symptoms were associated with lower hair cortisol concertration and lower saliva cortisol reactivity among girls. This study provides the first evidence for the notion that depressive symptoms in boys are associated with long-term cortisol concertration in hair, whereas anxiety symptoms in girls are associated with HPA-axis hypoactivity, when hair cortisol concentrations and saliva cortisol reactivity to acute stress are assessed concurrently.

Antidepressant Outcomes Predicted by Genetic Variation in Corticotropin-Releasing Hormone Binding Protein

OBJECTIVE

Genetic variation within the hypothalamic-pituitary-adrenal (HPA) axis has been linked to risk for depression and antidepressant response. However, these associations have yet to produce clinical gains that inform treatment decisions. The authors investigated whether variation within HPA axis genes predicts antidepressant outcomes within two large clinical trials.

METHOD

The test sample comprised 636 patients from the International Study to Predict Optimized Treatment in Depression (iSPOT-D) who completed baseline and 8-week follow-up visits and for whom complete genotyping data were available. The authors tested the relationship between genotype at 16 candidate HPA axis single-nucleotide polymorphisms (SNPs) and treatment outcomes for three commonly used antidepressants (escitalopram, sertraline, and extended-release venlafaxine), using multivariable linear and logistic regression with Bonferroni correction. Response and remission were defined using the Hamilton Depression Rating Scale. Findings were then validated using the Predictors of Remission in Depression to Individual and Combined Treatments (PReDICT) study of outcome predictors in treatment-naive patients with major depression.

RESULTS

The authors found that the rs28365143 variant within the corticotropin-releasing hormone binding protein (CRHBP) gene predicted antidepressant outcomes for remission, response, and symptom change. Patients homozygous for the G allele of rs28365143 had greater remission rates, response rates, and symptom reductions. These effects were specific to drug class. Patients homozygous for the G allele responded significantly better to the selective serotonin reuptake inhibitors escitalopram and sertraline than did A allele carriers. In contrast, rs28365143 genotype was not associated with treatment outcomes for the serotonin norepinephrine reuptake inhibitor venlafaxine. When patients were stratified by race, the overall effect of genotype on treatment response remained. In the validation sample, the GG genotype was again associated with favorable antidepressant outcomes, with comparable effect sizes.

CONCLUSIONS

These findings suggest that a specific CRHBP SNP, rs28365143, may have a role in predicting which patients will improve with antidepressants and which type of antidepressant may be most effective. The results add to the foundational knowledge needed to advance a precision approach to personalized antidepressant choices.

The effect of an adverse psychological environment on salivary cortisol levels in the elderly differs by 5-HTTLPR genotype

BACKGROUND

An adverse psychological environment (e.g. stressful events or depression) has been shown to influence basal cortisol levels and cortisol response to stress. This differs depending on the adverse stimuli, but also varies across individuals and may be influenced by genetic predisposition. An insertion/deletion polymorphism in the serotonin transporter gene (5-HTTLPR) is a strong candidate in this regard.

OBJECTIVE

To investigate how stressful life events and depression are associated with diurnal cortisol levels in community-dwelling elderly and determine whether this varies according to genetic variability in the 5-HTTLPR.

METHODS

This population-based study included 334 subjects aged 65 and older (mean (SD) = 76.5 (6.3)). Diurnal cortisol was measured on two separate days, under quiet (basal) and stressful conditions. The number of recent major stressful events experienced during the past year was assessed from a 12-item validated questionnaire as an index of cumulative recent stressful events. Lifetime trauma was evaluated using the validated Watson's PTSD inventory, which evaluates the most severe traumatic or frightening experience according to DSM criteria. Depression was defined as having a Mini-International Neuropsychiatric Interview (MINI) diagnosis of current major depressive disorder or high levels of depressive symptoms (Center for Epidemiologic Studies-Depression Scale ≥16). 5-HTTLPR genotyping was performed on blood samples.

RESULTS

Exposure to stressful life events was associated with lower basal evening cortisol levels overall, and in the participants with the 5-HTTLPR L allele but not the SS genotype. The greatest effects (over 50% decrease, p < 0.001) were observed for the LL participants having experienced multiple recent stressful events or severe lifetime traumas. Participants with the L allele also had higher evening cortisol stress response. Conversely, depression tended to be associated with a 42% higher basal morning cortisol in the SS participants specifically, but did not modify the association between stressful events and cortisol levels.

CONCLUSION

An adverse psychological environment is associated with basal cortisol levels and cortisol stress response, but this differs according to 5-HTTLPR genotype.

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.

The exercise-glucocorticoid paradox: How exercise is beneficial to cognition, mood, and the brain while increasing glucocorticoid levels

Exercise is known to have beneficial effects on cognition, mood, and the brain. However, exercise also activates the hypothalamic-pituitary-adrenal axis and increases levels of the glucocorticoid cortisol (CORT). CORT, also known as the "stress hormone," is considered a mediator between chronic stress and depression and to link various cognitive deficits. Here, we review the evidence that shows that while both chronic stress and exercise elevate basal CORT levels leading to increased secretion of CORT, the former is detrimental to cognition/memory, mood/stress coping, and brain plasticity, while the latter is beneficial. We propose three preliminary answers to the exercise-CORT paradox. Importantly, the elevated CORT, through glucocorticoid receptors, functions to elevate dopamine in the medial prefrontal cortex under chronic exercise but not chronic stress, and the medial prefrontal dopamine is essential for active coping. Future inquiries may provide further insights to promote our understanding of this paradox.

Sex differences in morning cortisol in youth at ultra-high-risk for psychosis

Research suggests abnormalities in hypothalamic-pituitary-adrenal (HPA) axis function play an important role in the pathophysiology of psychosis. However, there is limited research on the biological stress system in young people at ultra high risk (UHR) for psychosis. Morning cortisol levels are particularly relevant to study in this context, as these markers reflect HPA regulation. This is the first examination of sex differences in morning cortisol levels in UHR individuals. Twenty-eight UHR and 22 matched healthy control participants were assessed in respect to symptoms and had home-based collection of salivary cortisol over three time points in the morning. It was predicted that the UHR participants would exhibit lower morning cortisol levels and lower cortisol would be associated with greater symptomatology (i.e. higher positive, negative, and depressive symptoms). Additionally, sex differences in morning cortisol levels were explored based on recent evidence suggesting that sex differences may play an important role in the exacerbation of psychosis. While there were no group differences in morning salivary cortisol secretion, there was a sex by time interaction among UHR individuals, such that only UHR males exhibited flat cortisol levels across two hours after awakening, whereas UHR females had a pattern of cortisol secretion similar to healthy controls, even among medication-free individuals (F=6.34, p=0.004). Cortisol AUC (area under the curve) across the three time points had a trend association (medium effect size; r=0.34, p=0.08) with depressive, but not positive or negative, symptom severity. These results stress the importance of considering sex differences in the psychosis-risk period, as they improve understanding of pathogenic processes.

The Involvement of Genes in Adolescent Depression: A Systematic Review

Numerous studies have reported on the roles of genetic factors in the development of depression in adolescents and young adults. However, there are few systematic reviews that update our understanding of adolescent depression with the biological findings identifying the roles of gene expression and/or polymorphism(s). This review systematically summarized the findings that clearly identified the contribution of a gene to the risk of depression in adolescents between the ages of 10 and 19 years old and young adults between the ages of 20 and 25 years old. Data were obtained through searching PubMed, Embase, and Web of Science. A total of 47 studies on early adolescence and three studies on young adults were included in the current review. Most articles studied genes in the serotonergic system (n = 26), dopaminergic system (n = 3), and the Brain-derived neurotropic factor (BDNF) gene (n = 12). 92.3% of studies (24/26) identified positive associations of 5-HTTLPR polymorphism with depressive illness or depressive symptoms. 83.3% of studies (10/12) found positive association between BDNF Val66Met genotype and adolescent depressive symptoms. More studies should be conducted on the 18 genes reported in a few studies to clarify their roles in the risk for adolescent depression.

Predicting first onset of depression in young girls: Interaction of diurnal cortisol and negative life events

Interactions between biological vulnerability and environmental adversity are central to the pathophysiology of depression. Given evidence that the hypothalamic-pituitary-adrenal (HPA) axis influences biological responses to environmental events, in the current longitudinal study the authors examined HPA-axis functioning, negative life events, and their interaction as predictors of the first onset of depression. At baseline, girls ages 9 to 14 years provided saliva samples to assess levels of diurnal cortisol production, quantified by total cortisol production (area under the curve with respect to ground; AUCg) and the cortisol awakening response (CAR). The authors then followed these participants until they reached age 18 in order to assess their subsequent experience of negative life events and the onset of a depressive episode. They found that the influence of negative life events on the subsequent onset of depression depended on HPA-axis functioning at baseline. Specifically, negative life events predicted the onset of depression in girls with higher levels of AUCg, but not in girls with lower levels of AUCg. In contrast, CAR did not predict the onset of depression either alone or in interaction with negative life events. These findings suggest that elevated total cortisol production in daily life potentiates susceptibility to environmental adversity and signals the need for early intervention.

Genes, environments and depressions in young people

Among the common mental illnesses in childhood and adolescence, the unipolar depressions are the most concerning. These mental illnesses are aetiologically and clinically heterogeneous and little is known about their pathophysiology. This selected review considers the contribution of genetic and environmental factors in the emergence of these illnesses in the second decade of life.

Predicting mental disorders from hypothalamic-pituitary-adrenal axis functioning: a 3-year follow-up in the TRAILS study

BACKGROUND

Hypothalamic-pituitary-adrenal axis functioning, with cortisol as its major output hormone, has been presumed to play a key role in the development of psychopathology. Predicting affective disorders from diurnal cortisol levels has been inconclusive, whereas the predictive value of stress-induced cortisol concentrations has not been studied before. The aim of this study was to predict mental disorders over a 3-year follow-up from awakening and stress-induced cortisol concentrations.

METHOD

Data were used from 561 TRAILS (TRacking Adolescents' Individual Lives Survey) participants, a prospective cohort study of Dutch adolescents. Saliva samples were collected at awakening and half an hour later and during a social stress test at age 16. Mental disorders were assessed 3 years later with the Composite International Diagnostic Interview (CIDI).

RESULTS

A lower cortisol awakening response (CAR) marginally significantly predicted new disorders [odds ratio (OR) 0.77, p = 0.06]. A flat recovery slope predicted disorders with a first onset after the experimental session (OR 1.27, p = 0.04). Recovery revealed smaller, non-significant ORs when predicting new onset affective or anxiety disorders, major depressive disorder, or dependence disorders in three separate models, corrected for all other new onsets.

CONCLUSIONS

Our results suggest that delayed recovery and possibly reduced CAR are indicators of a more general risk status and may be part of a common pathway to psychopathology. Delayed recovery suggests that individuals at risk for mental disorders perceived the social stress test as less controllable and less predictable.

Prospective associations between sedentary time, sleep duration and adiposity in adolescents

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We examined sedentary time and sleep length relative to changes in youth adiposity.

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Sedentary time was not associated with change in adiposity in either gender.

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Sleep duration was significantly inversely associated with adiposity gain in boys.

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The association for sleep in boys was attenuated by physical activity and depression.

Objective

The objective of this study was to investigate whether objectively measured sedentary time and sleep duration are associated with changes in adiposity from mid- to late adolescence.

Methods

Students (n = 504, 42% boys) were recruited from schools in Cambridgeshire, UK. At baseline (mean age 15.0 ± 0.3 years), sedentary time was objectively measured by ≥3 days of combined heart rate and movement sensing. Concurrently, sleep duration was measured by combined sensing in conjunction with self-reported bed times. Fat mass index (FMI; kg/m²) was estimated at baseline and follow-up (17.5 ± 0.3 years) by anthropometry and bioelectrical impedance. FMI change (ΔFMI) was calculated by subtracting the baseline from follow-up values. Linear regression models adjusted for basic demographics, moderate-to-vigorous physical activity (MVPA), and depressive symptoms were used to investigate associations of sedentary time and sleep duration (mutually adjusted for one another) with ΔFMI.

Results

FMI increased by 0.5 and 0.6 kg/m² in boys and girls, respectively, but there was no association between sedentary time and ΔFMI in either gender (p ≥ 0.087), and no association between sleep duration and ΔFMI in girls (p ≥ 0.61). In boys, each additional hour of baseline sleep significantly reduced the ΔFMI by 0.13 kg/m² (p = 0.049), but there was little evidence for this association after adjusting for MVPA and depressive symptoms (p = 0.15).

Conclusions

Sedentary time may not determine changes in adiposity from mid- to late adolescence, nor may sleep duration in girls. However, sleep length may be inversely associated with adiposity gain in boys, depending on whether the relationship is confounded or mediated by MVPA and depression.

Glucagon-like peptide 1 receptor (GLP1R) haplotypes correlate with altered response to multiple antipsychotics in the CATIE trial

Glucagon-like peptide 1 receptor (GLP1R) signaling has been shown to have antipsychotic properties in animal models and to impact glucose-dependent insulin release, satiety, memory, and learning in man. Previous work has shown that two coding mutations (rs6923761 and rs1042044) are associated with altered insulin release and cortisol levels. We identified four frequently occurring haplotypes in Caucasians, haplotype 1 through haplotype 4, spanning exons 4-7 and containing the two coding variants. We analyzed response to antipsychotics, defined as predicted change in PANSS-Total (dPANSS) at 18 months, in Caucasian subjects from the Clinical Antipsychotic Trial of Intervention Effectiveness treated with olanzapine (n=139), perphenazine (n=78), quetiapine (n=14), risperidone (n=143), and ziprasidone (n=90). Haplotype trend regression analysis revealed significant associations with dPANSS for olanzapine (best p=0.002), perphenazine (best p=0.01), quetiapine (best p=0.008), risperidone (best p=0.02), and ziprasidone (best p=0.007). We also evaluated genetic models for the two most common haplotypes. Haplotype 1 (uniquely including the rs1042044 [Leu(260)] allele) was associated with better response to olanzapine (p=0.002), and risperidone (p=0.006), and worse response to perphenazine (p=.03), and ziprasidone (p=0.003), with a recessive genetic model providing the best fit. Haplotype 2 (uniquely including the rs6923761 [Ser(168)] allele) was associated with better response to perphenazine (p=0.001) and worse response to olanzapine (p=.02), with a dominant genetic model providing the best fit. However, GLP1R haplotypes were not associated with antipsychotic-induced weight gain. These results link functional genetic variants in GLP1R to antipsychotic response.

Early life adversity and serotonin transporter gene variation interact at the level of the adrenal gland to affect the adult hypothalamo-pituitary-adrenal axis

The short allelic variant of the serotonin transporter (5-HTT) promoter-linked polymorphic region (5-HTTLPR) has been associated with the etiology of major depression by interaction with early life stress (ELS). Furthermore, 5-HTTLPR has been associated with abnormal functioning of the stress-responsive hypothalamo-pituitary-adrenal (HPA) axis. Here, we examined if, and at what level, the HPA-axis is affected in an animal model for ELS × 5-HTTLPR interactions. Heterozygous and homozygous 5-HTT knockout rats and their wild-type littermates were exposed daily at postnatal days 2-14 to 3 h of maternal separation. When grown to adulthood, plasma levels of adrenocorticotropic hormone (ACTH), and the major rat glucocorticoid, corticosterone (CORT), were measured. Furthermore, the gene expression of key HPA-axis players at the level of the hypothalamus, pituitary and adrenal glands was assessed. No 5-HTT genotype × ELS interaction effects on gene expression were observed at the level of the hypothalamus or pituitary. However, we found significant 5-HTT genotype × ELS interaction effects for plasma CORT levels and adrenal mRNA levels of the ACTH receptor, such that 5-HTT deficiency was associated under control conditions with increased, but after ELS with decreased basal HPA-axis activity. With the use of an in vitro adrenal assay, naïve 5-HTT knockout rats were furthermore shown to display increased adrenal ACTH sensitivity. Therefore, we conclude that basal HPA-axis activity is affected by the interaction of 5-HTT genotype and ELS, and is programmed, within the axis itself, predominantly at the level of the adrenal gland. This study therefore emphasizes the importance of the adrenal gland for HPA-related psychiatric disorders.

Epigenetic and epistatic interactions between serotonin transporter and brain-derived neurotrophic factor genetic polymorphism: insights in depression

Epidemiological studies have shown significant results in the interaction between the functions of brain-derived neurotrophic factor (BDNF) and 5-HT in mood disorders, such as major depressive disorder (MDD). The latest research has provided convincing evidence that gene transcription of these molecules is a target for epigenetic changes, triggered by stressful stimuli that starts in early childhood and continues throughout life, which are subsequently translated into structural and functional phenotypes culminating in depressive disorders. The short variants of 5-HTTLPR and BDNF-Met are seen as forms which are predisposed to epigenetic aberrations, which leads individuals to a susceptibility to environmental adversities, especially when subjected to stress in early life. Moreover, the polymorphic variants also feature epistatic interactions in directing the functional mechanisms elicited by stress and underlying the onset of depressive disorders. Also emphasized are works which show some mediators between stress and epigenetic changes of the 5-HTT and BDNF genes, such as the hypothalamic-pituitary-adrenal (HPA) axis and the cAMP response element-binding protein (CREB), which is a cellular transcription factor. Both the HPA axis and CREB are also involved in epistatic interactions between polymorphic variants of 5-HTTLPR and Val66Met. This review highlights some research studying changes in the epigenetic patterns intrinsic to genes of 5-HTT and BDNF, which are related to lifelong environmental adversities, which in turn increases the risks of developing MDD.

Diurnal cortisol rhythms in youth from risky families: effects of cumulative risk exposure and variation in the serotonin transporter gene-linked polymorphic region (5-HTTLPR) [corrected]

Building on research on cumulative risk and psychopathology, this study examines how cumulative risk exposure is associated with altered diurnal cortisol rhythms in an ethnically diverse, low-income sample of youth. In addition, consistent with a diathesis-stress perspective, this study explores whether the effect of environmental risk is moderated by allelic variation in the promoter region of the serotonin transporter gene-linked polymorphic region (5-HTTLPR). Results show that youth with greater cumulative risk exposure had flatter diurnal cortisol slopes, regardless of 5-HTTLPR genotype. However, the association of cumulative risk with average cortisol output (area under the curve [AUC]) was moderated by the 5-HTTLPR genotype. Among youth homozygous for the long allele, greater cumulative risk exposure was associated with lower cortisol AUC, driven by significant reductions in cortisol levels at waking. In contrast, there was a trend-level association between greater cumulative risk and higher cortisol AUC among youth carrying the short allele, driven by a trend-level increase in bedtime cortisol levels. Findings are discussed with regard to the relevance of dysregulated diurnal cortisol rhythms for the development of psychopathology and the implications of genetically mediated differences in psychophysiological adaptations to stress.

Are flatter diurnal cortisol rhythms associated with major depression and anxiety disorders in late adolescence? The role of life stress and daily negative emotion

Alterations in hypothalamic-pituitary-adrenal (HPA) axis functioning have been associated with major depression disorder (MDD) and some anxiety disorders. Few researchers have tested the possibility that high levels of recent life stress or elevations in negative emotion may partially account for the HPA axis alterations observed in these disorders. In a sample of 300 adolescents from the Youth Emotion Project, we examined associations between MDD and anxiety disorders, dimensional measures of internalizing symptomatology, life stress, mood on the days of cortisol testing, and HPA axis functioning. Adolescents with a past MDD episode and those with a recent MDD episode comorbid with an anxiety disorder had flatter diurnal cortisol slopes than adolescents without a history of internalizing disorders. Higher reports of general distress, a dimension of internalizing symptomatology, were also associated with flatter slopes. Negative emotion, specifically sadness and loneliness, was associated with flatter slopes and partially accounted for the associations between comorbid MDD and anxiety disorders and cortisol. The associations between past MDD and cortisol slopes were not accounted for by negative emotion, dimensional variation in internalizing symptomatology, or levels of life stress, indicating that flatter cortisol slopes may also be a "scar" marker of past experiences of MDD.

Elevated morning cortisol is a stratified population-level biomarker for major depression in boys only with high depressive symptoms

Major depressive disorder (MD) is a debilitating public mental health problem with severe societal and personal costs attached. Around one in six people will suffer from this complex disorder at some point in their lives, which has shown considerable etiological and clinical heterogeneity. Overall there remain no validated biomarkers in the youth population at large that can aid the detection of at-risk groups for depression in general and for boys and young men in particular. Using repeated measurements of two well-known correlates of MD (self-reported current depressive symptoms and early-morning cortisol), we undertook a population-based investigation to ascertain subtypes of adolescents that represent separate longitudinal phenotypes. Subsequently, we tested for differential risks for MD and other mental illnesses and cognitive differences between subtypes. Through the use of latent class analysis, we revealed a high-risk subtype (17% of the sample) demarcated by both high depressive symptoms and elevated cortisol levels. Membership of this class of individuals was associated with increased levels of impaired autobiographical memory recall in both sexes and the greatest likelihood of experiencing MD in boys only. These previously unidentified findings demonstrate at the population level a class of adolescents with a common physiological biomarker specifically for MD in boys and for a mnemonic vulnerability in both sexes. We suggest that the biobehavioral combination of high depressive symptoms and elevated morning cortisol is particularly hazardous for adolescent boys.

Cortisol awakening response and subsequent depression: prospective longitudinal study

BACKGROUND

Some studies have found an association between elevated cortisol and subsequent depression, but findings are inconsistent. The cortisol awakening response may be a more stable measure of hypothalamic-pituitary-adrenal function and potentially of stress reactivity.

AIMS

To investigate whether salivary cortisol, particularly the cortisol awakening response, is associated with subsequent depression in a large population cohort.

METHOD

Young people (aged 15 years, n = 841) from the Avon Longitudinal Study of Parents and Children (ALSPAC) collected salivary cortisol at four time points for 3 school days. Logistic regression was used to calculate odds ratios for developing depression meeting ICD-10 criteria at 18 years.

RESULTS

We found no evidence for an association between salivary cortisol and subsequent depression. Odds ratios for the cortisol awakening response were 1.24 per standard deviation (95% CI 0.93-1.66, P = 0.14) before and 1.12 (95% CI 0.73-1.72, P = 0.61) after adjustment for confounding factors. There was no evidence that the other cortisol measures, including cortisol at each time point, diurnal drop and area under the curve, were associated with subsequent depression.

CONCLUSIONS

Our findings do not support the hypothesis that elevated salivary cortisol increases the short-term risk of subsequent depressive illness. The results suggest that if an association does exist, it is small and unlikely to be of clinical significance.

Serotonin transporter genotype, salivary cortisol, neuroticism and life events: impact on subsequent psychopathology in healthy twins at high and low risk for affective disorder

OBJECTIVE

To investigate if cortisol alone or in interaction with other risk factors (familial risk, the serotonin transporter genotype, neuroticism and life events (LEs)) predicts onset of psychiatric disorder in healthy individuals at heritable risk.

MATRIAL AND METHODS

In a high-risk study, 234 healthy monozygotic and dizygotic twins with or without a co-twin history of affective disorder (high and low risk twins) were baseline assessed. Participants were followed up for seven years and then reassessed with a personal interview revealing whether they had developed psychiatric illness.

RESULTS

36 participants (15.4%) developed psychiatric disorder. Using Cox proportional hazards ratio (HR) estimates neither morning nor evening salivary cortisol at baseline did predict illness onset. In multivariate Cox models, the two-way interaction between morning cortisol and LEs lifetime before baseline was significantly associated with onset. Further, the HR of onset was higher concerning individuals carrying the short allele of the 5-HTTPLR and having experienced more LEs lifetime. Familial risk for affective disorder predicted illness and the risk of onset was further increased in individuals at familial risk carrying the short allele of the 5-HTTPLR.

CONCLUSIONS

Cortisol levels alone do not increase the risk of onset of psychiatric illness but the interaction of a lower cortisol level and the experience of more LEs do. The 5-HTTLPR genotype seems to interact and contribute to increased stress vulnerability in combination with other stress indicators of illness thereby adding to the risk of subsequent psychopathology.

Understanding Familial Risk for Depression: A 25-Year Perspective

Major depressive disorder (MDD) is among the most prevalent, debilitating, and costly of all illnesses worldwide. Investigators have made considerable progress in elucidating psychological and biological correlates of MDD; however, far less is known about factors that are implicated in risk for depression. Given the high risk for MDD associated with a family history of depression, investigators have worked to understand both the effects of parental depression on offspring and the mechanisms that might underlie familial risk for MDD. In this article, we describe the evolution of investigators' understanding of the psychobiological functioning of children of depressed parents, and we present recent findings concerning cognitive and neural aspects of risk for MDD using our high-risk sample as a context and foundation for this discussion. We integrate these data in a conceptualization of mechanisms underlying risk for depression, focusing on the constructs of emotion dysregulation and stress reactivity. Recognizing the 25-year anniversary of the Association for Psychological Science, we place this presentation in the context of the past 25 years of research on depression. We conclude by discussing the significance of emotion dysregulation and stress reactivity for studying risk for depression, for developing approaches to prevent MDD, and for moving theory and research in this field forward.

Prospective association of morning salivary cortisol with depressive symptoms in mid-life: a life-course study

OBJECTIVE

Associations of cortisol and depression vary at different life-stages, yet population-based, prospective studies are scarce. We aimed to assess associations of morning cortisol with depressive symptoms in mid-life taking account of lifetime psychological health.

METHODS

Participants were 5,403 men and women from the 1958 British Birth Cohort whose salivary cortisol was assessed at 45y (45min after waking (T1) and 3h later (T2)) and who completed the 5-item Mental-Health Index (MHI-5) about depressive symptoms at age 50y. Lifetime psychological health was identified from child and adult measures.

RESULTS

For women, higher T2 cortisol at 45y predicted depression (MHI-5 scores ≤52) at 50y (odds ratio [OR]=1.17; 95% confidence intervals [CI] 1.05,1.30 per standard deviation increase in T2 cortisol), attenuating when adjusted for current (45y) and previous (7-42y) psychological health (OR=1.11; 95% CI 0.98, 1.24). Similarly, an association in women of flatter cortisol delta (T2-T1) with depressive symptoms at 50y weakened after adjustment for current (45y) and previous (7-42y) psychological health. For men, lower T2 cortisol at 45y predicted greater depressive symptoms at 50y and the association strengthened when adjusted for lifetime psychological health. Likewise, lower cortisol AUC predicted higher risk of depression for men after adjusting for prior psychological health (OR=0.85; CI 0.72, 1.00). Associations were largely unaltered by control for covariates.

CONCLUSIONS

In women, higher cortisol in late morning at 45y is prospectively associated with depressive symptoms at 50y through a link with lifetime psychological health. In men, lower cortisol predicts subsequent symptoms, independent of depressive history.

Rumination, anxiety, depressive symptoms and subsequent depression in adolescents at risk for psychopathology: a longitudinal cohort study

BACKGROUND

A ruminative style of responding to low mood is associated with subsequent high depressive symptoms and depressive disorder in children, adolescents and adults. Scores on self-report rumination scales correlate strongly with scores on anxiety and depression symptom scales. This may confound any associations between rumination and subsequent depression.

METHODS

Our sample comprised 658 healthy adolescents at elevated risk for psychopathology. This study applied ordinal item (non-linear) factor analysis to pooled items from three self-report questionnaires to explore whether there were separate, but correlated, constructs of rumination, depression and anxiety. It then tested whether rumination independently predicted depressive disorder and depressive symptoms over the subsequent 12 months, after adjusting for confounding variables.

RESULTS

We identified a single rumination factor, which was correlated with factors representing cognitive symptoms of depression, somatic symptoms of depression and anxiety symptoms; and one factor representing adaptive responses to low mood. Elevated rumination scores predicted onset of depressive disorders over the subsequent year (p = 0.035), and levels of depressive symptoms 12 months later (p < 0.0005), after adjustment for prior levels of depressive and anxiety symptoms.

CONCLUSION

High rumination predicts onset of depressive disorder in healthy adolescents. Therapy that reduces rumination and increases distraction/problem-solving may reduce onset and relapse rates of depression.

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.

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.

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.

No interaction between serotonin transporter gene (5-HTTLPR) polymorphism and adversity on depression among Japanese children and adolescents

BACKGROUND

Identification of gene × environment interactions (G × E) for depression is a crucial step in ascertaining the mechanisms underpinning the disorder. Earlier studies have indicated strong genetic influences and numerous environmental risk factors. In relation to childhood and adolescent depression, evidence is accumulating that the quality of the parental environment is associated with serotonin biology in children. We hypothesized that maternal depression is a crucial environmental risk factor associated with serotonin-regulating genes.

METHODS

This study was designed to ascertain the G × E interaction for diagnosis of depression in a Japanese pediatric sample. DNA samples from 55 pediatric patients with depression and 58 healthy schoolchildren were genotyped for the 5-HTT (2 short (S) alleles at the 5-HTT locus) promoter serotonin-transporter-linked polymorphic region (5-HTTLPR) polymorphism. We examined whether an adverse parental environment, operationalized as the mother's history of recurrent major depressive disorder, interacts with 5-HTTLPR polymorphism to predict patients' depression symptoms.

RESULTS

Binary logistic regression analyses revealed that maternal depression (adversity), gender, and FSIQ significantly affect the diagnosis of depression among children and adolescents. However, no main effect was found for adversity or genotype. Results of multivariable logistic regression analyses using stepwise procedure have elicited some models with a good fit index, which also suggests no interaction between 5-HTTLPR and adversity on depression.

CONCLUSIONS

To assess G × E interaction, data obtained from children and adolescents who had been carefully diagnosed categorically and data from age-matched controls were analyzed using logistic regression. Despite an equivocal interaction effect, adversity and gender showed significant main effects.

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?

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.

Genetic load is associated with hypothalamic-pituitary-adrenal axis dysregulation in macaques

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis pathway is associated with several neuropsychiatric disorders, including post-traumatic stress disorder (PTSD), major depressive disorder (MDD), schizophrenia and alcohol abuse. Studies have demonstrated an association between HPA axis dysfunction and gene variants within the cortisol, serotonin and opioid signaling pathways. We characterized polymorphisms in genes linked to these three neurotransmitter pathways and tested their potential interactions with HPA axis activity, as measured by dexamethasone (DEX) suppression response. We determined the percent DEX suppression of adrenocorticotropic hormone (ACTH) and cortisol in 62 unrelated, male rhesus macaques. While DEX suppression of cortisol was robust amongst 87% of the subjects, ACTH suppression levels were broadly distributed from -21% to 66%. Thirty-seven monkeys from the high and low ends of the ACTH suppression distribution (18 'high' and 19 'low' animals) were genotyped at selected polymorphisms in five unlinked genes (rhCRH, rhTPH2, rhMAOA, rhSLC6A4 and rhOPRM). Associations were identified between three variants (rhCRH-2610C>T, rhTPH2 2051A>C and rh5-HTTLPR) and level of DEX suppression of ACTH. In addition, a significant additive effect of the 'risk' genotypes from these three loci was detected, with an increasing number of 'risk' genotypes associated with a blunted ACTH response (P = 0.0009). These findings suggest that assessment of multiple risk alleles in serotonin and cortisol signaling pathway genes may better predict risk for HPA axis dysregulation and associated psychiatric disorders than the evaluation of single gene variants alone.

Association between the dexamethasone suppression test and serotonin transporter availability in healthy volunteer: a SPECT with [(123)I] ADAM study

Most common psychiatric diseases have been found to be associated with disturbance of both the hypothalamic-pituitary-adrenal (HPA) axis and the brain serotonergic system. The aim of this study was to explore the neuroendocrine relationships between the dexamethasone suppression test (DST) and serotonin transporter (SERT) availability in healthy volunteers. Sixty-six participants (30 males and 36 females) were recruited from the community. The DST suppression rate (D%) is the reduction in cortisol level from Day 1 (D1) to Day 2 (D2) in proportion to the Day 1 cortisol level (D%=(D1-D2)/D1×100%). SPECT with [(123)I] ADAM was used to measure SERT availability. A significant correlation between D% and SERT availability was noted in all subjects (Spearman's ρ=0.26, p=0.03) and in the male subjects (Spearman's ρ=0.41, p=0.02). SERT availability may be sensitive to changes in DST, especially in males.

Future directions in vulnerability to depression among youth: integrating risk factors and processes across multiple levels of analysis

Depression is a developmental phenomenon. Considerable progress has been made in describing the syndrome, establishing its prevalence and features, providing clues as to its etiology, and developing evidence-based treatment and prevention options. Despite considerable headway in distinct lines of vulnerability research, there is an explanatory gap in the field's ability to more comprehensively explain and predict who is likely to become depressed, when, and why. Still, despite clear success in predicting moderate variance for future depression, especially with empirically rigorous methods and designs, the heterogeneous and multi-determined nature of depression suggests that additional etiologies need to be included to advance knowledge on developmental pathways to depression. This paper advocates for a multiple levels of analysis approach to investigating vulnerability to depression across the lifespan and providing a more comprehensive understanding of its etiology. One example of a multiple levels of analysis model of vulnerabilities to depression is provided that integrates the most accessible, observable factors (e.g., cognitive and temperament risks), intermediate processes and endophenotypes (e.g., information-processing biases, biological stress physiology, and neural activation and connectivity), and genetic influences (e.g., candidate genes and epigenetics). Evidence for each of these factors as well as their cross-level integration is provided. Methodological and conceptual considerations important for conducting integrative, multiple levels of depression vulnerability research are discussed. Finally, translational implications for how a multiple levels of analysis perspective may confer additional leverage to reduce the global burden of depression and improve care are considered.