Daily provision of instrumental and emotional support to friends is associated with diurnal cortisol during adolescence.

This study investigates how adolescents' daily prosocial behaviors to friends are related to diurnal cortisol using between- and within-subject analyses. Further, we examine whether role fulfillment (i.e., feeling like a good friend) moderates links between prosocial behaviors and cortisol. Ethnically diverse adolescents (N = 370; ages 11-18) reported whether they provided instrumental and emotional support to friends for 5 days, and provided four saliva samples/day for 4 days. On the daily level, providing emotional support predicted lower cortisol awakening response the next day, and providing instrumental assistance to friends was associated with a flatter cortisol slope the same day (a cardiovascular risk factor). Adolescents also provided more emotional support on days they had lower CAR and steeper cortisol slopes. On the average level, providing more instrumental support was associated with steeper cortisol slopes among adolescents who felt high levels of role fulfillment, but not among adolescents who felt low levels of role fulfillment. Providing instrumental support may be physiologically taxing from day to day but, across the long term, linked to lower cardiovascular risk for adolescents who experience helping as highly fulfilling.

Role Fulfillment Mediates the Association Between Daily Family Assistance and Cortisol Awakening Response in Adolescents.

Family assistance (helping the family) is associated with both positive and negative psychological and biological outcomes during adolescence. However, the association between family assistance and the hypothalamic-pituitary-adrenal (HPA) axis remains unstudied. Thus, we assess how helping the family relates to adolescents' diurnal cortisol, an index of HPA activity, and psychological outcomes. Three hundred and seventy ethnically diverse adolescents (ages 11-18) reported daily helping behaviors and psychological experiences for 14 days and provided four saliva samples per day for 4 days. Multilevel modeling revealed that cortisol awakening response was lower the day after adolescents helped their families more. This association was explained, in part, by perceived role fulfillment (feeling like a good son, daughter, and sibling). Results highlight a possible psychological and biological benefit of assisting the family during adolescence.

Stress-Induced Suppression of Food Intake in Overweight and Obese Adolescents.

OBJECTIVE: Overweight adolescents exhibit greater cortisol reactivity in response to acute stress and are more likely to eat in response to emotional cues, which suggest an increased susceptibility to stress-induced eating. The purpose of this study was to examine the biological (cortisol and α-amylase reactivity) and behavioral (caloric intake) responses to an acute stressor in overweight adolescents. METHODS: Fifty-one adolescents ages 14 to 19 years (47% female, 55% white; body mass index, 31.2 ± 0.8 kg/m) were exposed to the Trier Social Stress Test and a control condition on separate days. Immediately after each condition, participants were provided with snacks to eat at their leisure. Reactivity was assessed via salivary cortisol and α-amylase area under the curve (AUC), and adolescents were categorized as high or low reactors. RESULTS: Cortisol AUC was higher during the stress condition (19.6 ± 0.2 µg/dl · min) compared with the control condition (11.4 ± 0.9 µg/dl · min, p < .001). α-Amylase AUC was not different during the stress condition (9999 ± 987 U/ml · min) compared with the control condition (8762 ± 865 U/ml · min, p = .145). Overall, adolescents consumed fewer calories during the stress condition (488 ± 51 kcal) compared with the control condition (637 ± 42 kcal, p = .007). High cortisol reactors decreased their calorie consumption from the control condition (716 ± 52 kcal) to the stress condition (457 ± 53 kcal, p = .001), whereas low cortisol reactors did not change their consumption (stress: 518 ± 87 kcal versus control: 561 ± 62 kcal, p = .574). CONCLUSION: High cortisol reactivity in overweight adolescents resulted in decreased calorie consumption after an acute stressor. Further research is needed to understand the mechanisms underlying stress-induced suppression of food intake in overweight adolescents.

Day-to-day friends' victimization, aggression perpetration, and morning cortisol activity in late adolescents.

This study investigates bidirectional associations between adolescents' daily experiences of victimization and aggression perpetration within friendships. We investigated (a) across-day associations between victimization and aggression perpetration; (b) morning cortisol activity as a moderator of cross-day victimization and aggression links; and (c) potential sex differences in these patterns. For 4 consecutive days, 99 adolescents (Mage  = 18.06, SD = 1.09, 46 females) reported whether they were victimized by or aggressive toward their friends. On three of these days, adolescents provided three morning saliva samples. Multilevel path analyses showed that across days, victimization and aggression were bidirectionally linked, but only for male adolescents. Additionally, for male adolescents, morning cortisol output (but not morning cortisol increase) moderated the association between victimization and next-day aggression; victimization predicted greater next-day aggression for boys with low, but not high, morning cortisol output. Findings implicate a physiological factor that may modify daily links between victimization and aggression in male adolescent friendships.

Population-neuroscience study of the Tokyo TEEN Cohort (pn-TTC): Cohort longitudinal study to explore the neurobiological substrates of adolescent psychological and behavioral development.

AIM: Adolescence is a crucial stage of psychological development and is critically vulnerable to the onset of psychopathology. Our understanding of how the maturation of endocrine, epigenetics, and brain circuit may underlie psychological development in adolescence, however, has not been integrated. Here, we introduce our research project, the population-neuroscience study of the Tokyo TEEN Cohort (pn-TTC), a longitudinal study to explore the neurobiological substrates of development during adolescence. METHODS: Participants in the first wave of the pn-TTC (pn-TTC-1) study were recruited from those of the TTC study, a large-scale epidemiological survey in which 3171 parent-adolescent pairs were recruited from the general population. Participants underwent psychological, cognitive, sociological, and physical assessment. Moreover, adolescents and their parents underwent magnetic resonance imaging (MRI; structural MRI, resting-state functional MRI, and magnetic resonance spectroscopy), and adolescents provided saliva samples for hormone analysis and for DNA analysis including epigenetics. Furthermore, the second wave (pn-TTC-2) followed similar methods as in the first wave. RESULTS: A total of 301 parent-adolescent pairs participated in the pn-TTC-1 study. Moreover, 281 adolescents participated in the pn-TTC-2 study, 238 of whom were recruited from the pn-TTC-1 sample. The instruction for data request is available at: http://value.umin.jp/data-resource.html. CONCLUSION: The pn-TTC project is a large-scale and population-neuroscience-based survey with a plan of longitudinal biennial follow up. Through this approach we seek to elucidate adolescent developmental mechanisms according to biopsychosocial models. This current biomarker research project, using minimally biased samples recruited from the general population, has the potential to expand the new research field of population neuroscience.

Hair and Salivary Testosterone, Hair Cortisol, and Externalizing Behaviors in Adolescents.

Although testosterone is associated with aggression in the popular imagination, previous research on the links between testosterone and human aggression has been inconsistent. This inconsistency might be because testosterone's effects on aggression depend on other moderators. In a large adolescent sample ( N = 984, of whom 460 provided hair samples), we examined associations between aggression and salivary testosterone, hair testosterone, and hair cortisol. Callous-unemotional traits, parental monitoring, and peer environment were examined as potential moderators of hormone-behavior associations. Salivary testosterone was not associated with aggression. Hair testosterone significantly predicted increased aggression, particularly at low levels of hair cortisol (i.e., Testosterone × Cortisol interaction). This study is the first to examine the relationship between hair hormones and externalizing behaviors and adds to the growing literature that indicates that androgenic effects on human behavior are contingent on aspects of the broader endocrine environment-in particular, levels of cortisol.

Adolescent oxytocin response to stress and its behavioral and endocrine correlates.

Oxytocin (OXT) shows anxiolytic and stress-reducing effects, but salivary OXT response to laboratory-induced stress has only been assessed in one study in healthy adults. The present study aimed at extending these findings by assessing salivary OXT stress reactivity in healthy adolescents (aged 11-18) compared to a control condition. A higher salivary OXT response to stress compared to the control condition was expected. In addition, the association between OXT, cortisol (CORT) and psychological reactivity patterns was explored. Psychosocial stress was induced using the Trier Social Stress Test (TSST; 13 males, 15 females), while the Control-TSST (14 males, 15 females) served as a non-stress control condition. Salivary OXT increased in response to the TSST with a peak at +1 and decline at +10 min after stress. Baseline OXT correlated negatively with experienced anxiety and insecurity, while both correlated positively with OXT reactivity. OXT and CORT increase as well as OXT increase and CORT recovery were positively correlated. Results indicate that salivary OXT in response to the TSST is a valid method to assess biological effects of laboratory-induced stress also in adolescents. Due to a rapid increase and decline, salivary OXT needs to be assessed directly after stress exposure. Given the interplay of OXT with affective symptoms and CORT response, the combined measure of salivary OXT and CORT reactivity adds to studying stress reactivity in typically developing and clinical samples.

Development of Multifaceted Risk Taking and the Relations to Sex Steroid Hormones: A Longitudinal Study.

Risk taking is a multidimensional construct. It is currently unclear which aspects of risk-taking change most during adolescence and if/how sex hormones contribute to risk-taking tendencies. This study applied a longitudinal design with three time-points, separated by 2 years, in participants aged 8-29 years (670 observations). The Balloon Analogue Risk Task, a delay discounting task, and various self-report questionnaires were administered, to measure aspects of risk taking. Longitudinal analyses demonstrated mostly nonlinear age-related patterns in risk-taking behavior and approach-related personality characteristics (peaking in late adolescence). Increased testosterone and estradiol were found to increase risk-taking behavior and impulsive personality, but decrease avoidance-like personality. This study demonstrates that risk taking is most pronounced in mid-to-late adolescence and suggests that sex hormones accelerate this maturational process.

An exploratory analysis of the joint contribution of HPA axis activation and motivation to early adolescent depressive symptoms.

This study examines the interactive contribution of the hypothalamic-pituitary-adrenal (HPA) axis and approach-avoidance motivation systems to longitudinal changes in depressive symptoms across the adolescent transition. In the summer prior to, or fall of, 4th grade, 132 youth (68 girls; 64 boys; M age = 9.46 years) participated in a social challenge task and reported on their depressive symptoms. In the winter of 6th grade, youth completed a semi-structured interview of depression and a self-report measure of approach-avoidance motivations. Analyses revealed two profiles of risk for adolescent depressive symptoms, with some gender differences: (1) excessive disengagement, reflected in HPA underactivation along with low approach motivation or high avoidance motivation; and (2) excessive engagement, reflected in HPA overactivation along with high approach motivation. This research highlights the importance of a multi-system perspective on development, suggesting that the implications of HPA dysregulation for depressive symptoms are contingent on adolescents' tendencies toward approach versus avoidance.

Associations Between Marital Conflict and Adolescent Conflict Appraisals, Stress Physiology, and Mental Health.

The goal of the current study was to examine conflict appraisals and diurnal cortisol production as mediators of the robust association between marital conflict and adolescent adjustment problems. Parents reported their marital conflict and were observed engaging in a marital conflict discussion; they also reported adolescent internalizing and externalizing behaviors. Adolescents (n = 105, 52% female, 10-17 years of age) appraised their parents' marital conflict and reported their internalizing and externalizing behaviors. After the laboratory visit, adolescents provided four saliva samples on each of 2 consecutive days to assess diurnal cortisol production. More-negative marital conflict predicted more self-blame for parental conflict, which in turn predicted less robust decreases in cortisol across the day. Further, this flattened cortisol production pattern mediated the relationship between greater self-blame for parental conflict and adolescents' elevated internalizing behaviors. Feeling responsible for parental conflict appears to be particularly damaging in terms of physiological regulation and adjustment, and may therefore be a particularly useful intervention target.

Patterns of Adolescent Regulatory Responses During Family Conflict and Mental Health Trajectories.

Four distinct patterns of adolescents' behavioral, emotional, and physiological responses to family conflict were identified during mother-father-adolescent (M = 13.08 years) interactions. Most youth displayed adaptively regulated patterns comprised of low overt and subjective distress. Under-controlled adolescents exhibited elevated observable and subjective anger. Over-controlled adolescents were withdrawn and reported heightened subjective distress. Physiologically reactive adolescents had elevated cortisol coupled with low overt and subjective distress. Regulation patterns were associated with unique mental health trajectories. Under-controlled adolescents had elevated conduct and peer problems whereas over-controlled adolescents had higher anxiety and depressive symptoms. Physiologically reactive adolescents had low concurrent, but increasing levels of depressive, anxiety, and peer problem symptoms. Findings underscore the importance of examining organizations of regulatory strategies in contributing to adolescent mental health.

Adolescent Life Stress and the Cortisol Awakening Response: The Moderating Roles of Attachment and Sex.

This longitudinal study investigated how past versus current life stresses relate to adolescents' cortisol awakening response (CAR), an index of hypothalamic-pituitary-adrenal activity. Ninety-nine adolescents reported previous year life stress at ages 12 and 18. At the second assessment, participants also provided self-reports of parent and peer attachment and 3 days of cortisol samples. Current stress was associated with heightened CAR for both males and females, whereas past stress was associated with attenuated CAR for males. Attachment to peers buffered the relationship between past stress and attenuated CAR for all adolescents; attachment to parents was a buffer for male adolescents only. Results demonstrate the protective roles of adolescent relationships and highlight sex differences in biopsychosocial development across adolescence.

Chewing in adolescents with overweight and obesity: An exploratory study with behavioral approach.

Physiological and behavioral aspects of masticatory function may have an impact on nutritional status, which has been little studied. The aim was to perform a comprehensive evaluation of objective, subjective and behavioral aspects of masticatory function in 231 adolescents, aged 14-17 years and compare these parameters between normal-weight (n = 115) and adolescents with overweight/obesity (n = 116). Objective aspects were examined by the Oro-facial Myofunctional Evaluation-expanded protocol (OMES-e), determining the masticatory type, chewing time/frequency, abnormal movements, and other; masticatory performance (color changeable chewing gum) and bite force were also explored. The subjective and behavioral evaluations were assessed using the Quality of Mastication Function Questionnaire, which explores the masticatory behavior and frequency/intensity of difficulty in chewing different types of foods. Results were submitted to normality tests, Chi-square, unpaired t-test and Mann-Whitney. A multiple linear regression model was used to evaluate which of the variables under study contributed to the variation in Percent Body Fat (α = 0.05). The results showed that OMES-e total score differed significantly between groups, that is, individuals with overweight showed more changes in oro-facial myofunctional aspects than normal-weight ones. Unilateral mastication was more frequent among females with overweight/obesity. They also showed greater difficulty on Habits and Fruit domains, reporting the need of adding sauce to the meal to facilitate swallowing and peeling and cutting fruit (apples) in small pieces in order to better chew them. OMES-e total score also showed a significant relationship with Percent Body Fat. Masticatory performance evaluated by chewing gum and bite force did not differ between groups. This study showed that adolescents with excess weight presented changes in masticatory behavior and greater difficulty in performing the masticatory function comparing to normal-weight ones.

The relationship between meeting vigorous physical activity recommendations and burnout symptoms among adolescents: an exploratory study with vocational students.

This study examines how students who met the current recommendations for vigorous physical activity (VPA) of the American College of Sports Medicine (ACSM) and the Centers of Disease Control and Prevention (CDC) differ from peers who did not reach these standards with regard to self-reported burnout, before and after controlling for light physical activity and moderate physical activity. A sample of 144 vocational students (Mage =16.2 years, SD = 1.13, 98 males) completed the International Physical Activity Questionnaire, the Shirom-Melamed Burnout Measure, and the School Burnout Inventory. Bivariate correlations revealed that only VPA was associated with reduced burnout. Both the ACSM and CDC guidelines were useful to identify significant differences in burnout symptoms between students who met versus did not meet the standards. Health policy makers should develop strategies to integrate more VPA into the lives of adolescent students so as to reach a minimum of 60 min per week.

Biological stress regulation in female adolescents: a key role for confiding.

Attachment behaviors play a critical role in regulating emotion within the context of close relationships, and attachment theory is currently used to inform evidence-based practice in the areas of adolescent health and social care. This study investigated the association between female adolescents' interview-based attachment behaviors and two markers of hypothalamic-pituitary-adrenal axis activity: cortisol and dehydroepiandrosterone (DHEA). Unlike the classic stress hormone cortisol, there is very limited investigation of DHEA-a quintessential developmental hormone-in relation to attachment, especially in adolescents. Fifty-five healthy females mean age 14.36 (±2.41) years participated in the attachment style interview. A smaller cortisol awakening response was related to anxious attachment attitudes, including more fear of rejection, whereas greater morning basal DHEA secretion was only predicted by lower levels of reported confiding in one's mother. These attachment-hormone relationships may be developmental markers in females, as they were independent of menarche status. These findings highlight that the normative shifts occurring in attachment to caregivers around adolescence are reflected in adolescents' biological stress regulation. We discuss how studying these shifts can be informed by evolutionary-developmental theory.

Relational victimization, friendship, and adolescents' hypothalamic-pituitary-adrenal axis responses to an in vivo social stressor.

Adolescents' peer experiences may have significant associations with biological stress-response systems, adding to or reducing allostatic load. This study examined relational victimization as a unique contributor to reactive hypothalamic-pituitary-adrenal (HPA) axis responses as well as friendship quality and behavior as factors that may promote HPA recovery following a stressor. A total of 62 adolescents (ages 12-16; 73% female) presenting with a wide range of life stressors and adjustment difficulties completed survey measures of peer victimization and friendship quality. Cortisol samples were collected before and after a lab-based interpersonally themed social stressor task to provide measures of HPA baseline, reactivity, and recovery. Following the stressor task, adolescents discussed their performance with a close friend; observational coding yielded measures of friends' responsiveness. Adolescents also reported positive and negative friendship qualities. Results suggested that higher levels of adolescents' relational victimization were associated with blunted cortisol reactivity, even after controlling for physical forms of victimization and other known predictors of HPA functioning (i.e., life stress or depressive symptoms). Friendship qualities (i.e., low negative qualities) and specific friendship behaviors (i.e., high levels of responsiveness) contributed to greater HPA regulation; however, consistent with theories of rumination, high friend responsiveness in the context of high levels of positive friendship quality contributed to less cortisol recovery. Findings extend prior work on the importance of relational victimization and dyadic peer relations as unique and salient correlates of adaptation in adolescence.

The cortisol/DHEA ratio mediates the association between early life stress and externalizing problems in adolescent boys.

BACKGROUND: Despite evidence that early life stress (ELS) can influence the functioning of the hypothalamic-pituitary-adrenal (HPA) axis and increase maladaptive behaviors in adolescence, less attention has been paid to the role of the coordinated effects of the two primary adrenal hormones, cortisol and dehydroepiandrosterone (DHEA), in these associations. METHODS: 138 typically developing adolescents (76 females) reported the stressful events experienced during childhood and early adolescence across 30 domains. Two years later we assessed levels of externalizing problems and obtained salivary levels of cortisol and DHEA. Using causal moderated mediation analyses, we examined whether the ratio of cortisol to DHEA (CD ratio) mediates the association between ELS and subsequent externalizing problems. RESULTS: We found that ELS is associated with both a lower CD ratio and more externalizing problems. Importantly, a lower CD ratio mediated the association between ELS and externalizing problems in boys. CONCLUSIONS: An imbalance in adrenal hormones may be a mechanism through which ELS leads to an increase in externalizing problems in adolescent boys. These findings underscore the utility of using the CD ratio to index HPA-axis functioning.

Child maltreatment, dating perpetration of physical assault, and cortisol reactivity among disadvantaged female adolescents.

OBJECTIVE: Few studies have examined hypothalamic-pituitary-adrenal axis stress reactivity and its relationship to histories of child maltreatment and physical aggression. We examined the relation of a history of childhood sexual abuse (CSA) and perpetration of dating violence to patterns of cortisol change before (resting) and after (reactivity) exposure to a laboratory stressor. METHODS: In a sample of 40 disadvantaged sexually active female adolescent patients (ages 14-17 years), we collected self-reports of lifetime child maltreatment (5 types) and past-year female perpetration of physical assault (PA) acts toward a romantic partner. We assessed changes in salivary cortisol trajectories during resting and reactivity phases following the viewing of a teen dating violence vignette. RESULTS: Reports of CSA (CSA+ group) were associated with reports of perpetration of severe dating PA (PA+ group), but the relation of these reports to laboratory-assessed patterns of cortisol changes following the stressor was opposite. As compared with subjects without victimization or perpetration histories (referent group), the CSA+ group showed the most pronounced positive slope (reactivity), whereas the PA+ group showed the least positive slope following the laboratory stressor after the overlap between these groups was statistically adjusted. While showing less reactivity to the laboratory stressor, the PA+ group had higher levels of resting cortisol, which stayed high during reactivity as compared to the referent group. CONCLUSION: The laboratory paradigm to elicit neuroendocrine stress-related cortisol reactivity appears to be a promising tool for identifying altered cortisol physiology among female adolescents with mixed histories of CSA and perpetration of dating PA.

The stress response and adolescents' adjustment: the impact of child maltreatment.

Experience with and management of stress has implications for adolescents' behavioral and socioemotional development. This study examined the relationship between adolescents' physiological response to an acute laboratory stressor (i.e., Trier Social Stress Test; TSST) and anger regulation and interpersonal competence in a sample of 175 low-income urban adolescents (51.8% girls). Findings suggested that heightened reactivity as indicated by cortisol, heart rate, and blood pressure was associated with increased interpersonal competence and anger regulation. However, these findings were context dependent such that, for youth high in self-reported child maltreatment, heightened reactivity was associated with decreased interpersonal competence and anger regulation. Results highlight the importance of considering how context may condition the effect of stress reactivity on functioning during adolescence.

Prevalence and risk factors of sleep bruxism and wake-time tooth clenching in a 7- to 17-yr-old population.

Sleep-related bruxism (SB) and wake-time tooth clenching (TC) have been associated with temporomandibular disorders (TMDs), headache, and sleep and behavioral complaints. This study aimed to assess the prevalence and risk factors of these signs and symptoms in a 7- to 17-yr-old population (n = 604) seeking orthodontic treatment. Data were collected by questionnaire and by a clinical examination assessing craniofacial morphology and dental status. Sleep-related bruxism was reported by 15% of the population and TC was reported by 12.4%. The SB group (n = 58) was mainly composed of children (67.3% were ≤12 yr of age) and the TC group (n = 42) was mainly composed of adolescents (78.6% were ≥13 yr of age). The craniofacial morphology of over 60% of SB subjects was dental class II and 28.1% were a brachyfacial type. Compared with controls (n = 220), SB subjects were more at risk of experiencing jaw muscle fatigue [adjusted OR (AOR) = 10.5], headache (AOR = 4.3), and loud breathing during sleep (AOR = 3.1). Compared with controls, TC subjects reported more temporomandibular joint clicking (AOR = 5), jaw muscle fatigue (AOR = 13.5), and several sleep and behavioral complaints. Sleep- and wake-time parafunctions are frequently associated with signs and symptoms suggestive of TMDs, and with sleep and behavioral problems. Their clinical assessment during the planning of orthodontic treatment is recommended.