Psychoneuroendocrinology of children and adolescents

Inflammation and depression in young people: a systematic review and proposed inflammatory pathways

Depression onset peaks during adolescence and young adulthood. Current treatments are only moderately effective, driving the search for novel pathophysiological mechanisms underlying youth depression. Inflammatory dysregulation has been shown in adults with depression, however, less is known about inflammation in youth depression. This systematic review identified 109 studies examining the association between inflammation and youth depression and showed subtle evidence for inflammatory dysregulation in youth depression. Longitudinal studies support the bidirectional association between inflammation and depression in youth. We hypothesise multiple inflammatory pathways contributing to depression. More research is needed on anti-inflammatory treatments, potentially tailored to individual symptom profiles.

Associations Between Cardiorespiratory Fitness and Endocrine, Autonomous and Psychological Stress Reactivity in Male Adolescents

Abstract. High stress burden during adolescence can have severe long-term health consequences. While some studies reported that adults with higher fitness levels show lower stress reactivity, research on adolescents is scarce. Accordingly, the aim of the present study was to investigate the association between cardiorespiratory fitness and physiological and psychological stress reactivity in male adolescents. Forty-three healthy, male adolescents aged 16–20 years underwent the Physical Working Capacity 170 bicycle ergometer test to determine cardiorespiratory fitness. The Trier Social Stress Test (TSST) was used to trigger a stress reaction, which was measured physiologically with changes in salivary cortisol and alpha-amylase concentrations, and psychologically using self-rated changes in state-anxiety. Under consideration of potential confounders, hierarchical regression analyses were calculated for each outcome. For cortisol and psychological stress reactivity, fitness did not significantly explain variance. However, 28% of variance in alpha-amylase reactivity were explained by fitness and sleep complaints [adjusted R2 = .28, F(2, 36) = 8.36, p = .001], with 16% of variance explained by fitness alone (β = −.41, p = .006). Accordingly, higher fitness was associated with lower stress reactivity of the autonomous nervous system in male adolescents. The promotion of cardiorespiratory fitness may therefore be considered an important factor in preventing negative health consequences of stress in this age group.

Cortisol, inflammatory biomarkers and neurotrophins in children and adolescents with attention deficit hyperactivity disorder (ADHD) in Taiwan

BACKGROUND

Hypothalamus-Pituitary-Adrenal (HPA) axis dysregulation, inflammation and imbalance of neurotrophins have been suggested in attention deficit hyperactivity disorder (ADHD), but the results have not been conclusive. The aim of this study is to investigate the levels of salivary cortisol across 4-time points during the day, and of morning plasma inflammatory biomarkers and neurotrophins, in youth with ADHD and in typically developing youth (TD), with stratification by age, ADHD subtypes and oppositional defiant disorder (ODD) comorbidity in Taiwan.

METHODS

We conducted a case-control study measuring saliva cortisol levels at 4 different time points during the day (at awakening, noon, 1800 h and bedtime) and morning plasma levels of inflammatory and neurotrophins biomarkers in youth with ADHD (n = 98, age 6-18 years old with mean age 9.32 ± 3.05 years) and TD (n = 21, age 6-18 years old with mean age 9.19 ± 2.96 years) in Taiwan.

RESULTS

Our study showed that youth with ADHD had lower levels of bedtime salivary cortisol (effects size (ES) = -0.04, p = .023), with children with the combined form of the disorder (with inattention, hyperactivity and impulsivity all present) having the lowest awakening salivary cortisol levels. ADHD youth also had higher levels of plasma high-sensitivity C-reactive protein (hs-CRP) and interleukin (IL)-6 (ES = 0.85-1.20, p < .0001), and lower plasma tumor necrosis factor-alpha (ES = -0.69, p = .009) and brain-derived neurotrophic factors (BDNF) (ES = -1.13, p < .0001). Both ADHD groups regardless of ODD comorbidity had higher levels of IL-6 (p < .0001) and lower levels BDNF (p < .0001).

CONCLUSION

The lower bedtime salivary cortisol levels and higher levels of inflammatory biomarkers in youth with ADHD further support the role of abnormal HPA axis and inflammation in ADHD. Moreover, the lower levels of BDNF in ADHD also indicate that BDNF may be a potential biomarker in this disorder that is part of a broader biological dysfunction.

Adolescent personality: associations with Basal, awakening, and stress-induced cortisol responses

The purpose of the present study was to investigate the associations between personality facets and hypothalamic-pituitary-adrenal (HPA) axis functioning. Previous studies have mainly focussed on stress-induced HPA-axis activation. We hypothesized that other characteristics of HPA-axis functioning would have a stronger association with personality based on the neuroendocrine literature. Data (n = 343) were used from the TRacking Adolescents' Individual Lives Survey (TRAILS), a large prospective cohort study of Dutch adolescents. We studied the association between facets of Neuroticism, Extraversion, and Conscientiousness and basal cortisol, the cortisol awakening response (CAR), and four measures of stress-induced HPA-axis activity. Basal cortisol levels were related to facets of all three personality traits. The CAR and stress-induced cortisol were not related to personality. Possibly due to its more trait-like nature, basal cortisol seems more informative than stress-induced cortisol when investigating trait-like characteristics such as personality facets.

Psychosocial issues in pediatric inflammatory bowel disease: report of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition

Pediatric inflammatory bowel disease (IBD) can affect many areas of psychosocial functioning, and comprehensive medical care includes consideration of psychosocial issues as well as disease factors. The purpose of this clinical report is to review research on psychosocial functioning in pediatric IBD and to provide recommendations for care providers in the areas of psychopathology, health-related quality of life, and social, family, and school functioning. Youth with IBD are at increased risk for difficulty in all areas reviewed, and many psychosocial factors are associated with disease activity, which highlights the importance of monitoring psychosocial functioning as part of clinical care. Several interventions have empirical support or show promise for addressing psychosocial difficulty, and recommendations for monitoring and treating these issues are provided.

Pituitary volume prospectively predicts internalizing symptoms in adolescence

BACKGROUND

Early adolescence is a critical time for the development of both internalizing and externalizing disorders. We aimed to investigate whether pituitary volume, an index of hypothalamic-pituitary-adrenal (HPA) axis function, represents a vulnerability factor for the emergence of internalizing and externalizing symptoms during adolescence using a prospective, longitudinal design.

METHODS

One hundred and fifty-five adolescents completed 3T structural magnetic resonance imaging (MRI), symptom rating scales and a diagnostic interview during early adolescence (M age 12.6 years, SD .5 years); symptom rating scales were re-administered approximately three years later (M age 15.2 years). The volume of the pituitary gland was estimated by manually delineating its structure on MR images. The degree to which pituitary volumes prospectively predicted change in internalizing and externalizing symptoms across the two time-points was assessed using hierarchal linear regression, after controlling for the influence of gender, age, pubertal stage and intracranial volume.

RESULTS

Larger pituitary volumes prospectively predicted an increase in internalizing, but not externalizing, symptoms from early adolescence to mid-adolescence.

CONCLUSIONS

This study provides the first evidence that increased pituitary volume might represent a specific vulnerability marker for the development of internalizing symptoms during early to mid-adolescence.

Differences in hypothalamic-pituitary-adrenal axis functioning among children with ADHD predominantly inattentive and combined types

Some evidence suggests that the HPA axis may be dysfunctional in children with attention-deficit/hyperactivity disorder (ADHD). The aim of this study was to investigate whether a different pattern of HPA axis activity is found between the inattentive (I) and combined (C) subtypes of ADHD, in comparison with healthy control children. A total of 100 prepubertal subjects [52 children with ADHD combined type (ADHD-C), 23 children with ADHD predominantly inattentive type (ADHD-I), and 25 healthy control subjects] were studied. The effects of stress were studied by comparing cortisol responses to a psychosocial stressor, consisting of a public speaking task. Children with ADHD-I showed an elevated cortisol response to the psychosocial stressor, in contrast to children with ADHD-C who showed a blunted cortisol response to the psychosocial stressor. When a distinction was made between responders and non-responders (a subject was classified as a responder when there was an increase in cortisol reactivity), hyperactivity symptoms were clearly related to a lower cortisol reactivity to stress. The results indicate that a low-cortisol responsivity to stress may be a neurobiological marker for children with ADHD-C, but not for those with ADHD-I. Directions for future research and clinical implications are discussed.

Diurnal patterns of salivary cortisol across the adolescent period in healthy females

When examining the diurnal profile of the hormone cortisol in children and adolescents developmental issues are particularly relevant. Previous findings regarding relationships between cortisol secretory activity and reproductive (pubertal) maturation lack clarity and may reflect methodological inconsistencies between studies. This study examined the diurnal cortisol profile across female adolescence, with a particular focus on an obvious and unique marker of development: menarche. In a cross-sectional design, 61 healthy female adolescents aged 9-18 years (mean age 13.89 years, S.D.+/-2.72) collected eight saliva samples per day on two consecutive weekdays. Samples were collected at awakening, 15, 30 and 45min and 3, 6, 9 and 12h post-awakening in order to capture both the cortisol awakening response (CAR) and the subsequent period of decline. Demographic information was recorded and participants also completed the Spielberger State-Trait Anxiety Inventory. Patterns of cortisol secretion exhibited good intra-individual stability across the two sampling days. Participants evidenced a robust diurnal pattern, with cortisol levels peaking approximately 30-45min post-awakening (the CAR) and steadily declining concentrations over the remainder of the day. Differences according to developmental status (in terms of whether or not participants had experienced first menses: menarche) were observed in the time of peak secretion of the CAR, and these distinct patterns could not be accounted for by group differences in demographic, situational or psychological characteristics measured in this study. This effect for the CAR was associated with the onset of menarche alone, unlike cortisol levels over the remainder of the day. For those who had undergone menarche, were older and of greater BMI, cortisol levels remained higher over the day. There was a significant difference in cortisol concentrations at 6h post-awakening between pre- and post-menarche groups. Again, these differences in daytime cortisol secretory activity could not be attributed to situational or psychological factors. Establishing patterns of cortisol secretion in healthy female adolescents provides an important baseline from which to investigate hypothalamic-pituitary-adrenal (HPA) physiology, measured via salivary cortisol, in adolescent populations with known or suspected psychopathology.

Infusing neuroscience into the study and prevention of drug misuse and co-occurring aggressive behavior

The etiology of behavioral precursors to substance misuse and aggression is viewed from the perspective of a developmental, multifactorial model of complex disorders. Beginning at conception, genetic and environmental interactions have potential to produce a sequence of behavioral phenotypes during development that bias the trajectory toward high-risk outcomes. One pathway is theorized to emanate from a deviation in neurological development that predisposes children to affective and cognitive delays or impairments that, in turn, generate dysregulatory behaviors. The plasticity of these neurobiological systems is highly relevant to the prevention sciences; their functions are reliant upon environmental inputs and can be altered, for better or for worse, contingent upon the nature of the inputs. Thus, social contextual factors confer significant influence on the development of this neural network and behavioral outcomes by increasing risk for, or protecting (1) against, dysregulatory outcomes. A well-designed intervention can exploit the brain's plasticity by targeting biological and social factors at sensitive time points to positively influence emergent neurobiological functions and related behaviors. Accordingly, prevention research is beginning to focus on perturbations in developmental neural plasticity during childhood that increase the likelihood of risky behaviors and may also moderate intervention effects on behavior. Given that the more complex features of neurobiological functions underlying drug misuse and aggression (e.g., executive cognitive function, coping skills, affect regulation) do not coalesce until early adulthood when prefrontal-limbic brain networks consolidate, it is critical that mechanisms underlying developmental risk factors are identified. An empirically driven prevention approach, thus, may benefit from consideration of (i) the type, effect, and developmental timing of the environmental impact on the brain, and (ii) the type and effect on brain function, and developmental timing of the intervention. This translational approach promises to eventually offer some direction for the design of effective interventions to prevent drug misuse and concomitant aggression.

HPA-axis activity and externalizing behavior problems in early adolescents from the general population: the role of comorbidity and gender The TRAILS study

Contradictory findings on the relationship between hypothalamus-pituitary-adrenal (HPA)-axis activity and externalizing behavior problems could be due to studies not accounting for issues of comorbidity and gender. In a population-based cohort of 1768 (10- to 12-year-old) early adolescents, we used a person-oriented approach and a variable-oriented approach to investigate whether comorbidity with internalizing behavior problems and gender moderate the relationship between HPA-axis activity (cortisol awakening response and evening cortisol levels) and externalizing behavior problems. We found that: (1) in early adolescents with pure externalizing behavior problems, there was a particularly strong effect of gender, in that girls showed significantly higher total cortisol levels after awakening (AUC(G) levels) and a significantly higher cortisol awakening response (AUC(I) levels) than boys. (2) Girls with pure externalizing behavior problems showed a significantly higher cortisol awakening response (AUC(I) levels) than girls without behavior problems or girls with comorbid internalizing behavior problems. This effect was absent in boys. (3) Externalizing behavior problems, in contrast to internalizing behavior problems, were associated with higher evening cortisol levels. This effect might, however, result from girls with externalizing behavior problems showing the highest evening cortisol levels. Overall, we were unable to find the expected relationships between comorbidity and HPA-axis activity, and found girls with pure externalizing behavior problems to form a distinct group with regard to their HPA-axis activity. There is need for prospective longitudinal studies of externalizing behavior problems in boys and girls in relation to their HPA-axis activity. It would be useful to consider how other risk factors such as life events and family and parenting factors as well as genetic risks affect the complex relationship between externalizing behavior problems and HPA-axis activity.

Physiological and psychological stress responses in adults with attention-deficit/hyperactivity disorder (ADHD)

According to self-report and unsystematic observational data adult patients with attention-deficit/hyperactivity disorder suffer from increased vulnerability to daily life stressors. The present study examined psychological and physiological stress responses in adult ADHD subjects in comparison to healthy controls under laboratory conditions. Thirty-six subjects (18 patients with DSM-IV ADHD diagnosis, 18 sex- and age-matched healthy controls) underwent the Trier Social Stress Test (TSST; Kirschbaum, C., Pirke, K.-M., Hellhammer, D.H., 1993. The "Trier Social Stress Test"--a tool for investigating psychobiological stress responses in a laboratory setting. Neuropsychobiology 28, 76-81), a standardized psychosocial stress protocol which contains a stress anticipation phase and a stress phase with a free speech assignment and subsequent performance of a mental arithmetic. Physiological stress measures were salivary cortisol as an indicator of the HPA axis, heart rate (HR), and time- and frequency-domain heart rate variability (HRV) parameters. Subjective stress experience was measured via self-report repeatedly throughout the experimental session. In line with previous theoretical and empirical work in the field of childhood ADHD, it was hypothesized that the ADHD and control group would exhibit comparable baseline levels in all dependent variables. For ADHD subjects, we expected attenuated responses of the physiological parameters during anticipation and presence of the standardized stressor, but elevated subjective stress ratings. Hypotheses were confirmed for the baseline condition. Consistent with our assumptions in regard to the psychological stress response, the ADHD group experienced significantly greater subjective stress. The results for the physiological variables were mixed. While ADHD subjects revealed an attenuated HR during the stress phase, no significant group differences were found for the other parameters, although a trend was observed for both the low frequency/high frequency (LF/HF) ratio of the HRV power spectral analysis and salivary cortisol (the latter possibly indicating generally lower cortisol levels in ADHD subjects). In summary, the present findings are the first to demonstrate a significant alteration of a specific physiological stress measure (HR) and, more clearly, of psychological aspects of the stress response in adults suffering from ADHD. In regard to the physiological stress response, it is recommended that future studies employ larger sample sizes and a more comprehensive range of physiological stress parameters. Additionally, the issue of transferability of laboratory results to real life stressors needs to be addressed.

Cortisol is inversely correlated with aggression for those boys with attention deficit hyperactivity disorder who retain their reactivity to stress

We examined the relationship between the cortisol response to stress and aggression in patients with attention deficit hyperactivity disorder (ADHD). Based on a report stating that only some of the patients with ADHD retain their hypothalamic-pituitary-adrenal axis reactivity to stress, we separately analyzed the relationship between aggression and the cortisol response to stress in two groups according to their reactivity to stress. Using psychological testing as an indicator of stress, we measured the cortisol level in the saliva before and after administering a psychological test. Behavioral problems, including aggression, were assessed using the Korean version of the Child Behavior Checklist (K-CBCL). The increase of the cortisol level was inversely correlated with aggression in patients who retained their reactivity to stress. The absolute value of the decrease was negatively correlated with the attention score of the CBCL for the patients who showed decreases in cortisol after stress. For the patients who showed increases in their concentration of cortisol in reaction to stress, cortisol may play a protective role against aggression.

Adolescent depression: description, causes, and interventions

Depression is one of the most prevalent of the psychiatric disorders and is common among individuals with epilepsy. Depression often begins in adolescence. The present review focuses on adolescent depression. In particular, this review first summarizes the definition, description, and classification of adolescent depression. Next, potential causes of adolescent depression are reviewed from a vulnerability-stress perspective. This part of the review focuses on the role of stressors and how stressors interact with genetic, biological, cognitive, personality, and interpersonal vulnerabilities to predict adolescent depression. Last, clinical aspects of adolescent depression are reviewed, including treatment and prevention of depression and the relation to epileptic disorders in adolescence. In sum, a substantial percentage of youth with epilepsy and seizures exhibit depression, and many are not diagnosed or treated in a timely manner. The present review shows that there are valid, empirically based assessments, treatments, and preventions for depression in adolescence that hold promise for reducing the significant burden associated with depression.

Medication treatment for depression in children and adolescents

Depression in children and adolescents is relatively common and associated with significant morbidity and mortality-thus, it is strongly deserving of treatment. To date, there have been a number of randomized, controlled trials of both tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs) in the acute treatment of depression in youths. Surprisingly, the available data do not demonstrate TCA superiority over placebo for this disorder in this age group. There is, however, evidence of SSRI superiority to placebo, and longer-term treatment with SSRIs may help prevent recurrence. There is almost no data on other pharmacologic approaches. Effective use of the efficacious treatments also depends on effective case-finding and providing treatment, which families and youths will take in adequate quantity and duration. The right approaches to these aspects of effective treatment are greatly understudied.

Relation between anxiety and depressive disorders in childhood and adolescence

Current research indicates that there is a strong relationship between pediatric anxiety disorders and depression. Assessment measures show high rates of correlation between depression and anxiety and much of the overlap may be related to a common domain of negative affectivity. Anxious youth and depressed youth share a cognitive style marked by a negative bias in information processing. Anxiety disorders and depression are frequently comorbid in children and adolescents. About 25-50% of depressed youth have comorbid anxiety disorders and about 10-15% of anxious youth have depression. Twin and family studies have demonstrated that pediatric anxiety disorders and depression likely share some common genetic factors or influences. Selective serotonin reuptake inhibitors and cognitive-behavioral therapy have been shown in randomized controlled trials to be efficacious for both pediatric depression and anxiety disorders. Integrating the treatment literature with studies of phenomenology, biology and genetics indicates that pediatric anxiety disorders and depression may share a genetically determined neurobiological component that could involve neural circuits that include or are modulated by serotonergic neurons. This component could contribute to the negative affective temperament that appears to be common in both pediatric depression and anxiety disorders.

Tricyclic antidepressants and selective serotonin reuptake inhibitors: use during pregnancy, in children/adolescents and in the elderly

OBJECTIVE

Depressive disorders can occur at any point in the lifespan. One way of differentiating antidepressants is by examining their efficacy and safety in the special patient populations that exist along the lifespan. Thus, we examine clinical data that is available regarding the use of selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs) at three distinct points in the lifespan: childhood and adolescence, pregnancy and late adulthood.

METHOD

Literature regarding the use of antidepressants in children and adolescents, pregnancy and the elderly was reviewed.

RESULTS

Clinical data suggest that SSRIs should be first line treatment in children and adolescents as TCAs have questionable efficacy and definite safety issues. Similarly, although TCAs and SSRIs show equivalent efficacy in elderly patients, the safety profile of the SSRIs makes them a more prudent choice in this population. Finally, although there is no definitive data that contraindicates the use of a particular antidepressant in pregnancy, the bulk of reassuring pregnancy outcome data exists for the SSRIs, specifically for fluoxetine.

CONCLUSION

Although no single antidepressant can ever be recommended for every patient, SSRIs should be considered the first-line choice in the treatment of depression in special patient populations.

The importance of neurobiological research to the prevention of psychopathology

There is both a biological and environmental component to the neural substrates for various forms of psychopathology. Brain dysfunction itself not only constitutes a formidable liability to psychopathology, but also has an impact on environmental and social responses to the individual, compounding the risk for an adverse outcome. Environmental conditions, such as social and physical stimulus deprivation, poverty, traumatic stress, and prenatal drug exposure, can further compromise brain function in the context of existing liabilities. The relationship between genetic and environmental processes is interactive, fluid, and cumulative in their ability to influence an individual's developmental trajectory and alter subsequent behavioral outcomes. Given the codependent relationship between these processes, brain function is now believed to be malleable via manipulations of the environment in ways that may decrease liability for psychopathology. Research that explores these relationships and ways in which interventions can redirect this developmental track may substantially advance both the science and practice of prevention. Studies attempting to isolate the neurobiological effects of socioenvironmental factors are reviewed, implications for intervention strategies are discussed, and a future research agenda is proposed to provide greater insight into specific brain-environment relationships. Armed with this knowledge, prevention scientists may eventually design programs that directly target these effects to reverse or attenuate negative outcomes.

The adolescent brain and age-related behavioral manifestations

To successfully negotiate the developmental transition between youth and adulthood, adolescents must maneuver this often stressful period while acquiring skills necessary for independence. Certain behavioral features, including age-related increases in social behavior and risk-taking/novelty-seeking, are common among adolescents of diverse mammalian species and may aid in this process. Reduced positive incentive values from stimuli may lead adolescents to pursue new appetitive reinforcers through drug use and other risk-taking behaviors, with their relative insensitivity to drugs supporting comparatively greater per occasion use. Pubertal increases in gonadal hormones are a hallmark of adolescence, although there is little evidence for a simple association of these hormones with behavioral change during adolescence. Prominent developmental transformations are seen in prefrontal cortex and limbic brain regions of adolescents across a variety of species, alterations that include an apparent shift in the balance between mesocortical and mesolimbic dopamine systems. Developmental changes in these stressor-sensitive regions, which are critical for attributing incentive salience to drugs and other stimuli, likely contribute to the unique characteristics of adolescence.