Predicting developmental changes in internalizing symptoms: examining the interplay between parenting and neuroendocrine stress reactivity

Depression in the next generation is related with maternal behaviors: A cross-comparison by alternating rat's mother care

This study investigated the potential impacts of depressive rats' maternal behavior as an early life stress on the outcome of offspring as an adulthood. Offspring from the same mother were divided into two groups, half of them were fostered or remained by a depressive mother, and the other half remained or fostered by a control mother, respectively. The results showed that offspring fostered by depressive mothers presented significant depressive behaviors. Meanwhile, depressive mothers engaged in more grooming during the light cycle, but less off-the-pup behavior during the dark phase. In conclusion, offspring exposed to a postnatal depressive maternal environment developed a depressive-like behavior. Contrarily, postpartum maternal behaviors play an essential role, which might determine the outcome of the next generation. Furthermore, the appropriate timing of postpartum maternal caring sequences, which might eliminate prenatal stressful influences, was recognized and might be a promising approach for reducing children's predisposition to mental disorders in their life time.

Psychological and Physical Abuse and Cortisol Response to Stress: The Moderating Role of Psychosocial Resources

Child abuse is associated with alterations in the hypothalamic-pituitary-adrenal (HPA) axis functioning. However, the unique effects of psychological and physical abuse and protective factors against these effects remain largely unknown. To close these gaps, the present study examined the unique effects of psychological and physical abuse on cortisol stress response and explored the moderating role of psychosocial resources in these associations among a sample of Chinese preadolescent children (N = 150; aged 9-13 years; M_age = 10.69 years; 51% boys). The results showed that both psychological and physical abuse were associated with blunted cortisol reactivity slopes. Psychological abuse, but not physical abuse, was associated with lower peak cortisol values and flatter cortisol recovery slopes. Further, psychosocial resources moderated the association between abuse and hyporesponsiveness of the HPA axis. The association between psychological abuse and lower peak cortisol values and the association between physical abuse and steeper cortisol recovery slopes (faster cortisol recovery following the stressor) were observed only among children with low levels of psychosocial resources. These findings indicate the differential effects of psychological and physical abuse on various phases of cortisol stress response, and the protective role of psychosocial resources. This study also has practical implications, given that preadolescence serves as a critical period for maximizing benefit of interventions of adversity.

Effects of the healthy start randomized intervention on psychological stress and sleep habits among obesity-susceptible healthy weight children and their parents

Poor sleep and psychological stress are obesity determinants that are rarely included in obesity prevention programs. The aim was to report the effects of the Healthy Start randomized intervention on the secondary outcomes psychological stress and sleep duration and onset latency. Data was obtained from the Healthy Start randomized intervention conducted in 2009–2012 among Danish healthy weight children aged 2–6 years, who had either a high birth weight (>4,000 g), high maternal pre-pregnancy body mass index (>28 kg/m2), or low maternal educational level (≤10 years of schooling) and their parents. The intervention was designed to deliver improvements in diet and physical activity habits, optimization of sleep habits, and reduction of psychological family stress. The average intervention period was 15 months. Children with information on a 7-day sleep record, sleep onset latency, Strengths and Difficulties Questionnaire (SDQ), and a modified version of Parenting Stress Index (PSI) were included. The effects of the intervention on sleep habits, PSI scores, SDQ Total Difficulties (SDQ-TD) and Pro-social Behavior scores, and 95% Confidence Intervals (95% CI) were analyzed using linear regression intention-to-treat (n = 543 (intervention group n = 271, control group n = 272)) analyses. No statistically significant effects on sleep duration, sleep onset latency, PSI score, or SDQ Pro-social Behavior score were observed. Values both before and after the intervention were within the normal range both for children in the intervention and children in the control group. Mean change in SDQ-TD was 0.09 points (95% CI -0.57;0.59) in the intervention group, and -0.69 points (95% CI -1.16; -0.23) in the control group (p = 0.06). In conclusion, there were no intervention effects in relation to sleep duration, sleep onset latency, PSI score, or SDQ Pro-social behavior. There was an indication that children in the intervention group had slightly more behavioral problems than the control group after the intervention, but values were within normal range both before and after the intervention, and the difference is not considered to be clinically meaningful.

Attachment and Affect between Mothers with Depression and their Children: Longitudinal Outcomes of Child Parent Psychotherapy

The present investigation examined the longitudinal effects of Child-Parent Psychotherapy (CPP) for toddlers and their mothers with depression on: a) maternal affective expression, b) child affective expression, and c) mother-child cohesion. Mothers with depression (Mage = 31.7 years; 92.8% White, 3.5% Black, 2.1% Hispanic, 2.3% other) and their toddlers were randomized to receive CPP (DI; n = 66) or to a control group (DC; n = 64). Mothers without depression and their toddlers (NC; n = 68) were recruited as an additional comparison group. Dyads were assessed at baseline (T1; 20 months old), post-intervention (T2; 36 months old), and follow-up (T3; 9 years old). Data from a mother-child conflict task was coded as a measure of observed outcome variables. Change in post-intervention attachment security assessed via the Strange Situation was evaluated as a mediator between intervention condition and maternal and child affective expression and dyadic cohesion at T3. Change to secure attachment post-intervention significantly mediated the association between intervention condition and T3 maternal warmth and child anger/problem behavior. Toddlers of mothers with depression who received CPP showed higher rates of change to secure attachment compared to those in both the DC and NC groups. Dyads who changed to secure attachment at T2 displayed higher levels of maternal warmth at T3 and lower levels of child anger and problem behavior at T3. Implications for the use of CPP as a preventive intervention and the importance of attachment as a mediator of long-term outcomes are discussed.

Parenting practices in childhood and depression, anxiety, and internalizing symptoms in adolescence: a systematic review

PURPOSE

Parenting practices represent important and modifiable factors for health and wellbeing in children and adolescents; however, strength and quality of studies examining relationships between parenting practices in childhood and risk of depression and anxiety in adolescence are unclear. The objective of this systematic review was to synthesize the longitudinal literature that describes these associations.

METHODS

Six electronic databases were searched for articles published through March 2018. Eligible articles were published in the English language, peer-reviewed, and had prospective cohort study designs. Articles eligible for inclusion examined positive and negative parenting practices of parents and/or guardians when study subjects were between 0 and 9 years of age, and symptoms of depression, anxiety, and internalizing symptoms when subjects were between 10 and 19 years of age. Heterogeneity of included articles precluded meta-analysis: findings were reported narratively.

RESULTS

4558 references were screened for inclusion, and 19 articles met eligibility criteria and were included for review. Ten articles examined positive parenting practices, and four demonstrated statistically significant associations between positive parenting practices and lower risk of adolescent depression, anxiety, and/or internalizing symptoms. Fifteen articles examined negative parenting practices, and five demonstrated significant associations between negative parenting practices and higher risk of adolescent depression, anxiety, and/or internalizing symptoms.

CONCLUSION

This review demonstrates that the evidence base supporting longitudinal associations between parenting practices in childhood and adolescent symptoms of depression, anxiety, and internalizing problems is inconsistent. Findings from this review highlight limitations of the existing literature and identify understudied parenting dimensions that require further investigation.

Pathways from parenting practices to adolescent suicidality: Evidence on the role of emotional and behavioral symptoms from a prospective cohort of Canadian children

OBJECTIVE

To investigate longitudinal relationships between parenting practices in childhood and adolescent suicidality, and assess the mediating role of emotional and behavioral symptoms.

METHODS

Data were drawn from the National Longitudinal Survey of Children and Youth, a Canadian population-based longitudinal cohort study. The sample included 9,490 children aged 10-11 who were followed up biennially to ages 14-15. Parents reported their positive and punitive parenting practices when children were 10-11. Adolescents self-reported symptoms of depression/anxiety, hyperactivity, conduct disorder, and social aggression at 12-13, and past-year suicidal ideation and suicide attempts at 14-15.

RESULTS

The inverse associations between positive parenting at 10-11 and suicidal behaviors at 14-15 were significantly mediated by symptoms of hyperactivity, conduct disorder, and social aggression at 12-13. Direct relationships between punitive parenting and suicidal behaviors were observed. These associations were significantly mediated by hyperactivity and, among boys only, by conduct disorder and social aggression. The association between punitive parenting and suicide attempt was additionally mediated by depression/anxiety.

CONCLUSIONS

Parenting in childhood may be associated with adolescent suicidality both directly and indirectly through emotional and behavioral symptoms. Interventions aimed at reducing the use of harsh disciplinary strategies and promoting positive parent-child interactions may reduce the burden of adolescent suicidality.

Bilingual family communication and the impact of language anxiety on cortisol reactivity

OBJECTIVES

The effects of socially evaluated tasks on stress-related behavior and physiology are often studied under artificial experimental conditions, such as contrived public speaking. Less is known about these behavioral and physiological dimensions under more routine conditions, such as family interactions. Here, we tested whether language anxiety during bilingual family conversations correlated to cortisol reactivity and speech patterns and whether family members' ages moderated this effect.

METHODS

Individuals (N = 34) from Spanish-English bilingual families participated in prompted conversations in both languages with their family members and provided saliva that we assayed for cortisol. Participants responded to a survey about language anxiety, and we analyzed their conversations for code switching. We tested whether higher reported anxiety was correlated with increased cortisol reactivity and if participants' age moderated this effect.

RESULTS

Participants' reported language anxiety was not significantly correlated with cortisol reactivity after conversations in either language. However, age significantly moderated the effect of English language anxiety. Among younger individuals, higher English language anxiety was correlated with greater cortisol reactivity after the English conversations. Older individuals did not demonstrate this same pattern. Individuals who code-switched during the English conversations had higher English language anxiety than individuals who did not. Similar patterns were not observed for the Spanish conversations.

CONCLUSIONS

The physiological and verbal responses to English language anxiety may be reflective of the high pressure placed on English use among bilingual families in the U.S., and the greater cortisol reactivity of younger individuals suggests they may face more identity challenging acculturation pressure.

Adolescent Mental Health Following Exposure to Positive and Harsh Parenting in Childhood

OBJECTIVES

The purpose of the present study was to assess longitudinal associations between positive and harsh parenting in childhood and adolescent mental and behavioral difficulties.

METHODS

Data were drawn from Canada's population-based National Longitudinal Survey of Children and Youth (data collected from 1994 to 2009, analyzed 2018). The sample included 9,882 adolescents aged 12/13 years old. Parents self-reported positive and harsh parenting when children were 6/7, 8/9, and 10/11 years old. Symptoms of depression/anxiety, hyperactivity, physical aggression, social aggression, and suicidal ideation were self-reported by adolescents at age 12/13. Linear regression was used to examine the associations between parenting behaviors at each age and adolescent psychiatric symptoms, adjusted for children's baseline symptoms.

RESULTS

Harsh parenting at 10/11 was associated with elevated symptoms of early-adolescent physical aggression, social aggression, and suicidal ideation for boys only, and for all children at earlier ages. Beginning at age 8/9, harsh discipline was associated with elevated symptoms of depression/anxiety for boys only. Overall, positive parenting at age 6/7 was protective against depression/anxiety, physical aggression, and social aggression. Significant sex differences emerged beginning at age 8/9, with positive parenting associated with higher symptoms of depression/anxiety for boys only. Positive parenting at age 10/11 was associated with increased depression/anxiety, physical aggression, social aggression, and suicidal ideation among boys, but decreased symptoms of physical aggression, social aggression, and suicidal ideation among girls.

CONCLUSIONS

Results suggest that the impact of positive and harsh parenting may depend on age and sex, with harsh parenting being more detrimental to boys as they approach adolescence.

Developmental Pathways from Genetic, Prenatal, Parenting and Emotional/Behavioral Risk to Cortisol Reactivity and Adolescent Substance Use: A TRAILS Study

Cortisol reactivity is a frequently studied biomarker of substance use, though infrequently examined in adolescence. However, past research provides evidence that multiple developmental influences, including genetics and both prenatal and postnatal environmental influences, contribute both to cortisol reactivity and adolescent substance use. The aim of this study was to assess the impact of these earlier developmental influences on cortisol reactivity to a social stress challenge and adolescent substance use (smoking, alcohol, and marijuana use frequency assessed at age 16 years), using data from the TRacking Adolescents' Individual Lives Survey (TRAILS; N= 2230 adolescents, 51% female). Developmental pathways included polygenic risk, prenatal stress, warm parenting (age 11), and internalizing and externalizing problems (intercepts and change from 11-16 years). Cortisol reactivity was associated with smoking but not alcohol or marijuana use. Externalizing problems were the stronger predictor of adolescent substance use, but internalizing problems also had an important role. Prenatal stress and middle childhood parenting operated via middle childhood externalizing problems, and parenting also operated via trajectories of growth of externalizing problems in predicting adolescent substance use outcomes. Further, there were protective effects of internalizing problems for alcohol and marijuana use in the context of a more comprehensive model. These developmental influences did not attenuate the association of cortisol reactivity and smoking. These findings suggest a need to understand the broader developmental context regarding the impact of internalizing pathways to substance use, and that it is unlikely that cortisol reactivity and smoking are associated solely because of common developmental influences.

Overestimating Self-Blame for Stressful Life Events and Adolescents' Latent Trait Cortisol: The Moderating Role of Parental Warmth

Cognitive interpretations of stressful events impact their implications for physiological stress processes. However, whether such interpretations are related to trait cortisol-an indicator of individual differences in stress physiology-is unknown. In 112 early adolescent girls (M age = 12.39 years), this study examined the association between self-blame estimates for past year events and latent trait cortisol, and whether maternal warmth moderated effects. Overestimating self-blame (versus objective indices) for independent (uncontrollable) events was associated with lower latent trait cortisol, and maternal warmth moderated the effect of self-blame estimates on latent trait cortisol for each dependent (at least partially controllable) and interpersonal events. Implications for understanding the impact of cognitive and interpersonal factors on trait cortisol during early adolescence are discussed.

Maternal depression alters stress and immune biomarkers in mother and child

BACKGROUND

Exposure to maternal depression bears long-term negative consequences for children's well-being. Yet, no study has tested the joint contribution of maternal and child's hypothalamic pituitary axis and immune systems in mediating the effects of maternal depression on child psychopathology.

METHODS

We followed a birth cohort over-represented for maternal depression from birth to 10 years (N = 125). At 10 years, mother and child's cortisol (CT) and secretory immunoglobulin A (s-IgA), biomarkers of the stress and immune systems, were assayed, mother-child interaction observed, mothers and children underwent psychiatric diagnosis, and children's externalizing and internalizing symptoms reported.

RESULTS

Depressed mothers had higher CT and s-IgA levels and displayed more negative parenting, characterized by negative affect, intrusion, and criticism. Children of depressed mothers exhibited more Axis-I disorders, higher s-IgA levels, and greater social withdrawal. Structural equation modeling charted four paths by which maternal depression impacted child externalizing and internalizing symptoms: (a) increasing maternal CT, which linked with higher child CT and behavior problems; (b) augmenting maternal and child's immune response, which were associated with child symptoms; (c) enhancing negative parenting that predicted child social withdrawal and symptoms; and (d), via a combined endocrine-immune pathway suppressing symptom formation.

CONCLUSIONS

Our findings, the first to test stress and immune biomarkers in depressed mothers and their children in relation to social behavior, describe mechanisms of endocrine synchrony in shaping children's stress response and immunity, advocate the need to follow the long-term effects of maternal depression on children's health throughout life, and highlight maternal depression as an important public health concern.

Interparental conflict and child HPA-axis responses to acute stress: Insights using intensive repeated measures

Interparental conflict is a common source of psychosocial stress in the lives of children. The purpose of this study was to examine the association between recent interparental conflict and one component of the physiological stress response system, the hypothalamic-pituitary-adrenal (HPA)-axis. Parents of 42 children (ages 8-13 years) completed daily diaries of interparental conflict for 8 weeks. At the end of the 8 weeks, youth participated in the Trier Social Stress Test for Children (TSST-C) while providing 2 pre- and 4 poststress salivary cortisol samples. Youth whose fathers reported a pattern of increasing interparental conflict over the past 8 weeks demonstrated an exaggerated HPA-axis response to acute stress. Mother-reported interparental conflict was not associated with children's HPA-axis responses without accounting for fathers' reports. When accounting for fathers' reports, the offspring of mothers reporting higher average daily interparental conflict demonstrated an attenuated HPA-axis response to the stressor. By estimating both average exposure and recent patterns of change in exposure to conflict, we address the circumstances that may prompt attenuation versus sensitization of the HPA-axis in the context of interparental conflict. We conclude that the HPA-axis is sensitive to proximal increases in interparental conflict which may be one pathway through which stress affects health across development, and that incorporating father's reports is important to understanding the role of the family environment in stress responses. This study further demonstrates the value of using intensive repeated measures and multiple reporters to characterize children's psychosocial environment. (PsycINFO Database Record

HPA-Axis Activation as a Key Moderator of Childhood Trauma Exposure and Adolescent Mental Health

Individual differences in a child's sensitivity to stress may influence whether youth exposed to trauma develop symptoms of psychopathology. We examined the interaction between HPA-axis reactivity to an acute stressor and exposure to different types of childhood trauma as predictors of mental health symptoms in a sample of youth. Youth (n = 121, ages 9-16; 47% female) completed a standardized stress task, including 5 post-stress salivary cortisol samples. Parents also completed the Child Behavior Checklist as a measure of child internalizing and externalizing symptoms in the past month, and completed the Early Trauma Inventory (ETI) as a measure of their child's trauma exposure. More emotional abuse and non-intentional trauma were associated with greater internalizing symptoms. Youth exposed to physical abuse who demonstrated slower HPA-axis reactivity had elevated internalizing and externalizing symptoms. Youth exposed to emotional abuse or non-intentional traumatic events who demonstrated faster HPA-axis reactivity had elevated internalizing and externalizing symptoms. Profiles of exaggerated or attenuated HPA-axis reactivity to acute stress may be risk factors for psychopathology in children facing different stressful social environments.

Developmental psychoneuroendocrine and psychoneuroimmune pathways from childhood adversity to disease

Childhood adversity has been repeatedly and robustly linked to physical and mental illness across the lifespan. Yet, the biological pathways through which this occurs remain unclear. Functioning of the inflammatory arm of the immune system and the hypothalamic-pituitary-adrenal (HPA)-axis are both hypothesized pathways through which childhood adversity leads to disease. This review provides a novel developmental framework for examining the role of adversity type and timing in inflammatory and HPA-axis functioning. In particular, we identify elements of childhood adversity that are salient to the developing organism: physical threat, disrupted caregiving, and unpredictable environmental conditions. We propose that existing, well-characterized animal models may be useful in differentiating the effects of these adversity elements and review both the animal and human literature that supports these ideas. To support these hypotheses, we also provide a detailed description of the development and structure of both the HPA-axis and the inflammatory arm of the immune system, as well as recent methodological advances in their measurement. Recommendations for future basic, developmental, translational, and clinical research are discussed.

Father-adolescent engagement in shared activities: Effects on cortisol stress response in young adulthood

Parent-child relationships can critically affect youth physiological development. Most studies have focused on the influence of maternal behaviors, with little attention to paternal influences. The current study investigated father engagement with their adolescents in household (shopping, cooking) and discretionary leisure activities as a predictor of youth cortisol response to a challenging interpersonal task in young adulthood. The sample (N = 213) was roughly divided between Mexican American (MA; n = 101) and European American (EA; n = 112) families, and included resident biological-father (n = 131) and resident stepfather families (n = 82). Salivary cortisol was collected before, immediately after, and at 20 and 40 min after an interpersonal challenge task; area under the curve (AUCg) was calculated to capture total cortisol output. Results suggested that more frequent father engagement in shared activities with adolescents (ages 11-16), but not mother engagement, predicted lower AUCg cortisol response in young adulthood (ages 19-22). The relation remained significant after adjusting for current mother and father engagement and current mental health. Further, the relation did not differ given family ethnicity, father type (step or biological), or adolescent sex. Future research should consider unique influences of fathers when investigating the effects of parent-child relationships on youth physiological development and health. (PsycINFO Database Record

Cortisol response to family interaction as a predictor for adjustment

Emerging adult (EA) cortisol response during family interaction predicts change in EA anxious behavior during the transition to college (Johnson & Gans, in press). In the present study, we take an initial step toward integrating family systems research and physiology by including assessment of EA salivary cortisol collected during a triadic (mother-father-EA offspring) family interaction task. Emerging adults (N = 101) between the ages of 17 and 19 were assessed at 3 time points across their first college year: the summer before college, Fall and Spring semesters. Two parents accompanied the emerging adult child to the summer assessment; all family members provided 4 saliva samples each at 20-min intervals. Later assessments of emerging adults included measures of internalizing behaviors. EA's cortisol secretion patterns during family interaction predict observed and self-reported family relatedness, as well as patterns of internalizing behavior during the college transition. Observed family functioning appeared to moderate the relationship between EA cortisol response during family interaction and anxious behavior when adapting to college. Different patterns of results emerged, however, for EA men and women. The approach taken by this study provides a first step toward understanding how interrelationships among elements of physiology and family functioning contribute to later adjustment. (PsycINFO Database Record

A Longitudinal Study of the Effects of Child-Reported Maternal Warmth on Cortisol Stress Response 15 Years After Parental Divorce

OBJECTIVES

The experience of parental divorce during childhood is associated with an increased risk of behavioral and physical health problems. Alterations in adrenocortical activity may be a mechanism in this relation. Parent-child relationships have been linked to cortisol regulation in children exposed to adversity, but prospective research is lacking. We examined maternal warmth in adolescence as a predictor of young adults' cortisol stress response 15 years after parental divorce.

METHODS

Participants included 240 youth from recently divorced families. Mother and child reports of maternal warmth were assessed at 6 time points across childhood, adolescence, and young adulthood. Offspring salivary cortisol was measured in young adulthood before and after a social stress task. Structural equation modeling was used to predict cortisol response from maternal warmth across early and late adolescence.

RESULTS

Higher child-reported maternal warmth in early adolescence predicted higher child-reported maternal warmth in late adolescence (standardized regression = 0.45, standard error = 0.065, p < .01), which predicted lower cortisol response to a challenging interpersonal task in young adulthood (standardized regression = -0.20, standard error = 0.094, p = .031). Neither mother-reported warmth in early adolescence nor late adolescence was significantly related to offspring cortisol response in young adulthood.

CONCLUSIONS

Results suggest that for children from divorced families, a warm mother-child relationship after divorce and across development, as perceived by the child, may promote efficient biological regulation later in life.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01407120.

The Relationship Between Autonomy and Relatedness and Adolescents' Adrenocortical and Cardiovascular Stress Response

Developing autonomy and maintaining relatedness within the parent-adolescent relationship marks a realignment process that shifts adolescents' decision making and regulation from parents to youth. This process may be stressful for some adolescents, particularly those who perceive their daily lives as stressful. This study examined the associations of autonomy, relatedness and perceived stress with adolescents' cortisol and blood pressure response to conflict in a mother-adolescent interaction task among 100 adolescents (M age = 15.09; 68 % girls, 78 % Caucasian). Few direct associations were found, but results indicated that perceived stress moderated the effect of autonomy and relatedness such that youth who reported more perceived stress and whose mothers' restricted their autonomy and undermined their relatedness evidenced increased cortisol and systolic blood pressure when compared to youth lower in perceived stress. The results highlight the importance of examining individual differences in the association between normative developmental transitions and adolescents' neurobiological response to stress.

Differential associations between childhood trauma subtypes and adolescent HPA-axis functioning

Studies examining the association between childhood trauma exposure and neuroendocrine functioning have returned inconsistent findings. To date, few studies have accounted for the role exposure to different types of childhood trauma may have on different neuroendocrine adaptations, and no study has examined this association using multiple indices of hypothalamic-pituitary-adrenal axis (HPA-axis) functioning. The purpose of this study was to characterize the unique associations between exposure to physical abuse, emotional abuse, and non-intentional trauma, and multiple indices of HPA-axis functioning.

METHODS

A community sample of 138 youth (aged 9-16) completed the Socially Evaluated Cold Pressor Task (SE-CPT) while their parents completed the Early Trauma Inventory (ETI). All youth then collected 4 diurnal salivary cortisol samples at home across 2 consecutive weekdays.

RESULTS

High reported exposure to non-intentional trauma was associated with intact diurnal regulation but elevated cortisol at bedtime, physical abuse was associated with faster reactivity to acute stress, and emotional abuse was associated with delayed recovery of cortisol following acute stress. Taken together, there was a heterogeneous relationship among different indices of HPA-axis functioning and trauma subtype.

DISCUSSION

Different types of childhood trauma exposure are related to distinct anomalies in HPA-axis functioning. This study underscores the importance of research incorporating multiple indices of HPA-axis functioning to inform our understanding of the underlying neuroendocrine dysregulation that may later lead to stress-related psychopathology.

HPA-axis stress reactivity in youth depression: evidence of impaired regulatory processes in depressed boys

Given the link between youth depression and stress exposure, efforts to identify related biomarkers have involved examinations of stress regulation systems, including the hypothalamic-pituitary-adrenal (HPA) axis. Despite these vast efforts, the underlying mechanisms at play, as well as factors that may explain heterogeneity of past findings, are not well understood. In this study, we simultaneously examined separate components of the HPA-axis response (e.g. activation intensity, peak levels, recovery) to the Socially Evaluated Cold-Pressor Test in a targeted sample of 115 youth (age 9-16), recruited to overrepresent youth with elevated symptoms of depression. Among youth who displayed a cortisol response to the task, depression symptoms were associated with higher peak responses but not greater rate of activation or recovery in boys only. Among those who did not respond to the task, depression symptoms were associated with greater cortisol levels throughout the visit in boys and girls. Results suggest that depression symptoms are associated with a more prolonged activation of the axis and impaired recovery to psychosocial stressors primarily in boys. We discussed two potential mechanistic explanations of the link between depression symptoms and the duration of activation: (1) inhibitory shift (i.e. point at which the ratio of inhibitory and excitatory input into the axis shifts from greater excitatory to greater inhibitory input) or (2) inhibitory threshold (i.e. level of cortisol exposure required to activate the axis' feedback inhibition system).