Publications and Presentations

Publications

Diet quality and mental health problems in late childhood
Dimov et al. (2019). Diet quality and mental health problems in late childhood. Nutritional Neuroscience, DOI:10.1080/1028415X.2019.1592288
There is evidence that diet quality is associated with mental health problems in adults and adolescents. Yet the extent to which overall diet quality (not individual nutrients or dietary patterns) may be associated with mental health problems in pre-adolescent children, a common time for first onset of symptoms, remains unclear. This study examined associations between overall diet quality, using a brief measure, and mental health problems during late childhood, in a large community sample.
Participants were 787 eight and nine-year-old children taking part in the Childhood to Adolescence Transition Study. Parents reported on their child's mental health problems using the Strengths and Difficulties Questionnaire and on their child's diet quality, using a six-item screening tool.
Regression analyses were conducted, adjusting for child age, sex, body mass index, and family socioeconomic status. Overall diet quality was significantly associated with children's mental health before (beta = −0.11, 95% CI −0.18 to −0.04, p = 0.004) and after adjustments for age, sex, body mass index and family socioeconomic status (beta = −0.10, 95% CI −0.18 to −0.03, p = 0.007).
Concordant with previous literature, results indicate that better overall diet quality is related to more positive mental health in pre-adolescent children. Additionally, these results support the utility and efficacy of a brief (six-item) parent-report questionnaire as an indicator of overall diet quality.

Relationships between adrenarcheal hormones, hippocampal volumes and depressive symptoms in children
Ellis, R. et al. (2019). Relationships between adrenarcheal hormones, hippocampal volumes and depressive symptoms in children. Psychoneuroendocrinology, 104:55-63.
Early timing of puberty (i.e., advanced pubertal maturation relative to same-age peers) has been associated with depressive symptoms during adolescence. To date, research on this relationship has focused on gonadarche, the second phase of puberty, while less is known about the first phase of puberty, adrenarche. Increasing evidence suggests that androgens that rise during adrenarche, most notably dehyrdoepiandrosterone (DHEA) and testosterone, may be involved both in the development of the hippocampus, and risk for depression. The current study investigated whether hippocampal volumes mediated the relationship between adrenarcheal timing (based on relative levels of adrenarcheal hormones) and depressive symptoms in children. Data were collected from a cross-sectional sample of 88 children (46 female) selected to have relatively increased variance in these androgens. Participants completed brain MRI structural scans, provided saliva samples for hormones, and completed the Children's Depression Inventory (CDI). Contrary to predictions, larger right hippocampi significantly partially mediated the positive relationship between early timing of testosterone exposure (i.e., relatively high levels of testosterone for one's age) and depressive symptoms in girls. No other evidence of significant mediation effects was obtained, however DHEA and testosterone exposure showed unique effects on hippocampal volumes in males and females, and larger hippocampal volumes predicted higher depressive symptoms in the entire sample. These results suggest that adrenarcheal timing may be related to hippocampal development and depressive symptoms, extending current knowledge of pubertal risk processes.

Publications

Bullying, mental health and friendship in Australian primary school children.
Bayer et al. (2018). Bullying, mental health and friendship in Australian primary school children. Child and Adolescent Mental Health, 23(4), 334-340.
Puberty marks a transition in risk for body image disturbance and disordered eating. Yet few studies have examined these symptoms across puberty and none have examined links with adrenarche, the earliest phase in the pubertal hormonal cascade.
Levels of adrenal androgens (dehydroepiandrosterone, dehydroepiandrosterone sulphate, and testosterone) were measured in a population-based study of 8- to 9-year-old children (516 males and 621 females). Body dissatisfaction was measured using the Kids’ Eating Disorder Scale Silhouettes. Covariates included body mass index, age, and socioeconomic status.
There were significant associations between adrenal androgen levels and greater body dissatisfaction in both males and females. Specifically, females with more advanced levels of dehydroepiandrosterone and testosterone relative to peers, and males with more advanced levels of testosterone relative to peers, reported greater body dissatisfaction. However, after adjusting for covariates, hormones levels were no longer associated with body dissatisfaction, and only higher body mass index had a clear association with body dissatisfaction.
The adrenarchal transition brings a heightened risk for body dissatisfaction. Whether this arises from the neuroendocrine effects of adrenal androgens or as a reaction to the greater body mass that accompanies adrenarche requires further exploration.

Body image dissatisfaction and the adrenarchal transition
Hughes et al. (2018). Body image dissatisfaction and the adrenarchal transition. Journal of Adolescent Health, 63(5), 621-627.
Frequent bullying predicts adolescent mental health problems, particularly depression. This population-based study with young Australian primary school children aimed to determine the frequency and mental health correlates of bullying, and whether friendship could be protective.
Participants were a population-based sample of 1221 children aged 8–9 years attending 43 primary schools in metropolitan Melbourne, Australia. Children were taking part in the Childhood to Adolescence Transition Study. Children completed online questionnaires at school to measure peer relations and emotional well-being. Parents reported on their child's mental health in questionnaires sent to the home.
One in three children (29.2%) reported experiencing frequent bullying, defined as at least once a week. This included physical bullying alone (13.8%), verbal bullying alone (22.7%) and the combination (7.4%). Children who reported being frequently bullied self-reported higher internalising symptoms compared with children who did not report frequent bullying (M (SD) 1.6 (0.9) vs. 1.1 (0.8), p < .001). This difference was confirmed by parents' reports of their child's internalising symptoms (M (SD) 2.4 (2.3) vs. 2.1 (2.0), p = .026, respectively). Amongst children who reported frequent bullying, those with a group of friends had better emotional well-being.
A substantial proportion of children report experiencing bullying on a weekly basis early in primary school. Given the prevalence of bullying in primary school and its relationship to children's mental health, we recommend effective school-wide antibullying programmes. Further research can explore whether intervention to foster a group of friends around bullied children can improve their emotional well-being.

Interaction between parenting styles and adrenarcheal timing associated with affective brain function in late childhood
Barbosa et al. (2018). Interaction between parenting styles and adrenarcheal timing associated with affective brain function in late childhood. Journal of the American Academy of Child & Adolescent Psychiatry, 57(9),678-686
Parenting and pubertal timing have consistently been associated with internalizing and externalizing symptoms in childhood and adolescence, and there is some evidence that the interaction between these factors may be important in conferring risk. However, few studies have investigated whether neurobiological factors mediate these relationships. The current study examined whether interactions between adrenarcheal timing and parenting styles were associated with affective brain function and, in turn, mental health difficulties.
Participants were 88 healthy children (46 female and 42 male, mean age 9.42 years, SD = 1.08 years), with 45 classified as relatively early and 43 as relatively late in adrenarcheal development based upon adrenal hormone levels. Participants completed an affective face functional magnetic resonance imaging task, and parents reported on 5 parenting styles and on child internalizing and externalizing symptoms.
Negative parenting styles (corporal punishment and poor monitoring) were associated with brain hemodynamic response while viewing affective faces in several subcortical and lateral prefrontal regions, and adrenarcheal timing and/or sex moderated most of these relationships. Sex differences in associations between corporal punishment and brain activation to affective faces indicated that late females might show less adaptive affective neural function when more exposed to this parenting style.
Findings suggest that the interaction between parenting styles and adrenarcheal timing is associated with affective brain function in late childhood, with marked sex differences. Further longitudinal research with larger samples is needed to corroborate and expand upon these findings.

Associations between adrenarcheal hormones, amygdala functional connectivity and anxiety symptoms in children
Barendse et al. (2018). Associations between adrenarcheal hormones, amygdala functional connectivity and anxiety symptoms in children. Psychoneuroendocrinology, 97, 156-163.
The transition from childhood to adolescence is a vulnerable period for the development of anxiety symptoms. There is some evidence that hormonal changes occurring during adrenarche, an early pubertal phase, might play a role in this increased vulnerability. Little is known about underlying brain mechanisms. Given the role of the amygdala-based fear circuit in anxiety, the current study aimed to investigate whether children's adrenarcheal hormone levels were associated with functional connectivity of the amygdala while processing fearful facial expressions, and how this in turn related to anxiety symptoms.
Participants were 83 children (M age 9.53 years) who completed two morning saliva collections to measure levels of dehydroepiandrosterone (DHEA), its sulphate (DHEAS), and testosterone. They also completed the Spence Children's Anxiety Scale (SCAS), and viewed fearful and calm facial expressions while undergoing a functional MRI scan. Psychophysiological interaction (PPI) analyses were performed to examine amygdala connectivity and significant clusters were fed into a bootstrapping mediation model.
In boys, mediation analyses showed an indirect positive effect of testosterone on anxiety symptoms, which was mediated by amygdala-secondary visual cortex connectivity as well as amygdala-anterior cingulate connectivity. In girls, DHEAS showed a negative indirect association with anxiety symptoms mediated by amygdala connectivity to the fusiform face area and insula.
The results indicate unique roles for adrenarcheal hormones in anxiety and suggest that amygdala connectivity may represent an important neural mechanism in these associations. Importantly, results reveal prominent sex differences in the biological mechanisms associated with anxiety in children undergoing adrenarche.

The effects on schooling outcomes of early developmental vulnerabilities in children
The Centre for Adolescent Health, Murdoch Children’s Research Institute (2018). The effects on schooling outcomes of early developmental vulnerabilities in children, Canberra: Australian Government Department of Education and Training.

Student wellbeing, engagement and learning across the middle years
The Centre for Adolescent Health, Murdoch Children’s Research Institute (2018). Student wellbeing, engagement and learning across the middle years, Canberra: Australian Government Department of Education and Training.

Presentations

The psychosocial profiles of children aged 11-12 years who have self-harmed: A prospective cohort study
Presented at the 40th Annual Society for Mental Health Research Conference, Noosa, Australia.

Publications

The association between electronic media and emotional and behavioral problems in late childhood
Mundy et al. (2017). The association between electronic media and emotional and behavioral problems in late childhood. Academic Pediatrics, 17(6), 620-624.
There is growing concern that rising rates of electronic media use might be harmful. However, the extent to which different types of electronic media use might be associated with emotional and behavioral problems is unclear. In this study we examined associations between emotional and behavioral problems and electronic media use during late childhood, in a large community sample.
Participants were 876 8- to 9-year-old children taking part in the Childhood to Adolescence Transition Study in Australia. Parents reported on their child's emotional and behavioral problems using the Strengths and Difficulties Questionnaire and on their child's duration of electronic media use (in hours: television, video games, general computer use).
Logistic regression analyses were conducted with adjustments for age, socioeconomic status, and body mass index z score, separately for male and female participants. Boys who played more video games had significantly greater odds of scoring borderline/abnormal on conduct (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.02–1.12) and emotional problems (OR, 1.07; 95% CI, 1.04–1.11) for each additional hour of weekly use. This equates to 2.58-fold greater odds for a boy who plays on average 2 hours per day per week. Television viewing was associated with greater odds of hyperactivity/inattention in boys (OR, 1.04; 95% CI, 1.00–1.07). There were no significant relationships for girls.
Because of the increasing rates of electronic media use in children, these results might have important implications for child mental health. Future interventions might be more effective if they are targeted at specific types of electronic media use.

Pain and learning in primary school: a population-based study
Kosola et al. (2017). Pain and learning in primary school: a population-based study. PAIN, 158(9), 1825-1830.
Despite the frequency of pain among children, little is known about its effects on learning and school outcomes. The objective of this study was to quantify the association of pain and academic achievement while taking into account the presence of co-occurring emotional symptoms. A population-based stratified random sample of 1239 students aged 8 to 9 years from primary schools in Melbourne, Australia, was recruited for the Childhood to Adolescence Transition Study. Children indicated sites of pain that had lasted for a day or longer in the past month using a pain manikin. Depressive- and anxiety-related symptoms were assessed using child-reported items. National assessment results for reading and numeracy were used to measure academic achievement. Sixty-five percent of children reported pain in at least 1 body site and 16% reported chronic pain. Increasing number of pain sites was associated with poorer reading scores in a dose–response fashion (β = −3.1; 95% confidence interval −4.9 to −1.3; P < 0.001). The association was only partly attenuated when adjusting for emotional symptoms (β = −2.6; 95% confidence interval −4.5 to −0.8; P < 0.001) and was not moderated by emotional symptoms. Children with chronic pain were a year behind their peers in both reading and numeracy. Among primary school students, pain was associated with lower reading scores even after adjusting for the presence of emotional symptoms. Although population-based longitudinal studies will be required to ascertain consistency and possible causality, grounds exist for considering pain and emotional symptoms in the assessment of children with reading difficulties.

Peer victimization and academic performance in primary school children
Mundy et al. (2017). Peer Victimization and Academic Performance in Primary School Children. Academic Pediatrics, 17(8), 830-836.
Peer victimization is a common antecedent of poor social and emotional adjustment. Its relationship with objectively measured academic performance is unclear. In this study we aimed to quantify the cross-sectional associations between peer victimization and academic performance in a large population sample of children.
Eight- to 9-year-old children were recruited from a stratified random sample of primary schools in Australia. Academic performance was measured on a national achievement test (1 year of learning equals 40 points). Physical and verbal victimization were measured according to child self-report.
Multilevel mixed-effects linear regression analyses were conducted. For female children, verbal victimization was associated with poorer academic performance on writing (β = 17.2; 95% confidence interval [CI], −28.2 to −6.2) and grammar/punctuation (β = −20.8; 95% CI, −40.1 to −1.6). Physical victimization was associated with poorer performance on numeracy (male children: β = −29.0; 95% CI, −53.8 to −4.1; female children: β = −30.1; 95% CI, −56.6 to −3.5), and writing (female children: β = −21.5; 95% CI, −40.4 to −2.7). Verbal and physical victimization were associated with poorer performance on reading (male children: β = −31.5; 95% CI, −59.9 to −3.1; female children: β = −30.2; 95% CI, −58.6 to −1.8), writing (female children: β = −25.5; 95% CI, −42.8 to −8.2), spelling (female children: β = −32.3; 95% CI, −59.6 to −4.9), and grammar/punctuation (female children: β = −32.2; 95% CI, −62.4 to −2.0).
Children who were physically victimized were 6 to 9 months behind their non-victimized peers on measures of academic performance. There are growing reasons for education systems to invest in the prevention of bullying and promotion of positive peer relationships from the earliest years of school.

Academic performance in primary school children with common emotional and behavioral problems
Mundy et al. (2017). Academic performance in primary school children with common emotional and behavioral problems. Journal of School Health, 87(8), 593-601.
Many emotional and behavioral problems first emerge in primary school and are the forerunners of mental health problems occurring in adolescence. However, the extent that these problems may be associated with academic failure has been explored less. We aimed to quantify the association between emotional and behavioral problems with academic performance.
A stratified random sample of 8- to 9-year-olds (N=1239) were recruited from schools in Australia. Data linkage was performed with a national assessment of academic performance to assess reading and numeracy. Parent report assessed emotional and behavioral problems with students dichotomized into "borderline/abnormal" and "normal" categories.
One in 5 grade 3 students fell in the "borderline/abnormal" category. Boys with total difficulties (β=-47.8, 95% CI: -62.8 to -32.8), conduct problems, and peer problems scored lower on reading. Numeracy scores were lower in boys with total difficulties (β=-37.7, 95% CI: -53.9 to -21.5) and emotional symptoms. Children with hyperactivity/inattention scored lower in numeracy. Girls with peer problems scored lower in numeracy.
Boys with emotional and behavioral problems in mid-primary school were 12 months behind their peers. Children with emotional and behavioral problems are at high risk for academic failure, and this risk is evident in mid-primary school.

Presentations

Who has a role to play in promoting healthy use of media?
Presented at the Australian Council on Children and the Media's (ACCM) one day "Tots and tech: Growing up well with media and technology" conference, Melbourne, Australia

The role of sleep problems in the development of musculoskeletal pain and chronic musculoskeletal pain in children
Presented at the International Symposium on Pediatric Pain

Developing an online social media presence for research
Presented by Kristina Bennett, Molly O'Sullivan, Elissa Phillips and Dr Lisa Mundy at the Australian Association for Adolescent Health Conference, Sydney, Australia.

Publications

The lifetime experience of traumatic events is associated with hair cortisol concentrations in community-based children
Simmons et al. (2016). The lifetime experience of traumatic events is associated with hair cortisol concentrations in community-based children. Psychoneuroendocrinology, 63, 276-281.
Adversity early in life can disrupt the functioning of the hypothalamic–pituitary–adrenal axis (HPAA) and increase risk for negative health outcomes. Recent research suggests that cortisol in scalp hair represents a promising measure of HPAA function. However, little is known about the relationship between early exposure to traumatic events and hair cortisol concentrations (HCC) in childhood, a critical period of HPAA development. The current study measured HCC in scalp hair samples collected from 70 community-based children (14 males, mean age = 9.50) participating in the Imaging Brain Development in the Childhood to Adolescence Transition Study (iCATS). Data were also collected on lifetime exposure to traumatic events and current depressive symptoms. Lifetime exposure to trauma was associated with elevated HCC; however, HCC was not associated with current depressive symptoms. Consistent with some prior work, males were found to have higher HCC than females, although results should be treated with caution due to the small number of males who took part. Our findings suggest that hair cortisol may represent a biomarker of exposure to trauma in this age group; however, further study is necessary with a particular focus on the characterization of trauma and other forms of adversity.

Depression, immune function, and early adrenarche in children
Delaney et al. (2016). Depression, immune function, and early adrenarche in children. Psychoneuroendocrinology, 63, 228-234.
Despite consistent findings of an association between depression and immunity in adult and adolescent populations, little is known about the nature of this relationship at earlier ages. Studies of children have yielded mixed results, suggesting methodological confounds and/or the presence of significant moderating factors. Timing of adrenarche, the first phase of puberty that occurs during late childhood, is a plausible moderator of the depression-immunity relationship in late childhood due to its associations with both the immune system and psychological wellbeing. We hypothesized that: (1) a depression-immunity association exists in children, (2) this association is moderated by adrenarcheal timing, and, (3) this association is also moderated by gender. Data were drawn from a nested study of 103 participants (62 females, Mage = 9.5, age range: 8.67–10.21 years) participating in a population based cohort study of the transition from childhood to adolescence (across puberty). Participants in this nested study completed the Children's Depression Inventory 2 (CDI-2) and provided morning saliva samples to measure immune markers (i.e., C-reactive protein, CRP; and secretory immunoglobulin A, SIgA). Using hierarchical regression, inflammation measured by CRP was positively associated with the negative mood/physical symptoms (NM/PS) subscale (β = 0.23, t = 2.33, p = 0.022) of the CDI-2. A significant interaction effect of SIgA x adrenarcheal timing was found for NM/PS (β = −0.39, t = −2.19, p = 0.031) and Interpersonal Problems (β = −0.47, t = −2.71, p = 0.008). SIgA and NM/PS were positively associated for relatively late developers. SIgA and Interpersonal Problems were positively associated for late developers, and negatively associated for early developers. We suggest that both sets of findings might be partially explained by the immunosuppressive effect of the hormonal changes associated with earlier adrenarche, namely testosterone. These results also suggest that adrenarcheal timing has an effect on the association between depression and immunity, and is therefore an important measure in research with younger populations. Future research should utilize longitudinal designs to demonstrate direction of influence of variables, and use a broader range of pro- and anti-inflammatory markers.

Associations between dehydroepiandrosterone (DHEA) levels, pituitary volume, and social anxiety in children
Murray et al. (2016). Associations between dehydroepiandrosterone (DHEA) levels, pituitary volume, and social anxiety in children. Psychoneuroendocrinology, 64, 31-39.
Early timing of adrenarche, associated with relatively high levels of dehydroepiandrosterone (DHEA) and its sulphate (DHEA-S) in children, has been linked with mental health problems, particularly anxiety. However, little is known about possible neurobiological mechanisms underlying this association. The pituitary gland is a key component of the hypothalamic–pituitary–adrenal (HPA) axis, the activation of which triggers the onset of adrenarche. The purpose of this study was to examine the extent to which pituitary gland volume mediated the relationship between levels of DHEA/DHEA-S relative to age (i.e., adrenarcheal timing) and symptoms of anxiety in 95 children (50 female, M age 9.50 years, SD 0.34 years). Relatively high DHEA and DHEA-S (DHEA/S) levels were found to be associated with larger pituitary gland volumes. There was no significant direct effect of relative DHEA/S levels on overall symptoms of anxiety. However, results supported an indirect link between relatively high DHEA/S levels and symptoms of social anxiety, mediated by pituitary gland volume. No sex differences were observed for any relationship. Our findings suggest that neurobiological mechanisms may be partly responsible for the link between relatively early adrenarche and anxiety symptoms in children. One possible mechanism for this finding is that an enlarged pituitary gland in children experiencing relatively advanced adrenarche might be associated with hyper-activity/reactivity of the HPA axis. Further research is needed to understand the role of stress in the link between adrenarcheal timing and HPA-axis function, especially in relation to the development of anxiety symptoms in children and adolescents.

Self-reported parenting style is associated with children’s inflammation and immune activation
Byrne et al. (2017). Self-reported parenting style is associated with children’s inflammation and immune activation. Journal of Family Psychology, 31(3), 374-380.
Family environments and parenting have been associated with inflammation and immune activation in children and adolescents; however, it remains unclear which specific aspects of parenting drive this association. In this study, we cross-sectionally examined the association between 5 discrete parenting styles and inflammation and immune activation in late childhood. Data were drawn from 102 families (55 with female children, mean age 9.50 years, SD = 0.34) participating in the Imaging Brain Development in the Childhood to Adolescence Transition Study. Children provided saliva samples from which inflammation (C-reactive protein) and immune competence/activation (secretory immunoglobulin A) were measured. Parents completed the Alabama Parenting Questionnaire, which measures 5 aspects of parenting style-positive parental involvement, positive disciplinary techniques, consistency in disciplinary techniques, corporal punishment, and monitoring and supervision. Results showed that higher scores on the poor parental monitoring scale were associated with higher levels of both inflammation and immune activation in children. This study highlights parental monitoring and supervision as a specific aspect of parenting behavior that may be important for children's physical and mental health.

Readiness for Secondary School: The Childhood to Adolescence Transition Study (CATS)
Deery, A., Mundy, L., Hardiman, K., Patton, G. (2016) Readiness for Secondary School: The Childhood to Adolescence Transition Study (CATS). Produced on behalf of the Victorian Government Department of Education and Training

The Childhood to Adolescence Transition Study (CATS): Analysis Report Waves 1-4
Mundy, L., Hoq, M., Canterford, L., Hardiman, K., Patton, G., (2016) The Childhood to Adolescence Transition Study (CATS): Analysis Report Waves 1-4. Produced on behalf of the Commonwealth Government Department of Education and Training

Presentations

Pain and Learning in Primary School: A Population-based Study
Presented at the European Public Health Conference, Vienna, Austria
Poster presented at International Congress of Pediatrics, Vancouver, Canada

Associations between social media use and emotional problems 
Presented at the Society for Mental Health Research Conference, Sydney, Australia

Preparing Students for the Transition to Secondary School
Presented by Lisa Mundy at the Australian Association for Research in Education Conference, Melbourne, Australia

The Middle Years: A Foundation for Future, Health, Wellbeing & School Engagement
Presented at the 2016 Home Economics Victoria Annual Conference

Birth weight and emotional and behavioural problems in early adolescence
Presented at the Society for Research on Adolescence Conference, Baltimore, USA

Electronic media use and academic performance in early adolescence
Presented at the Society for Research on Adolescence Conference, Baltimore, USA

Body dissatisfaction and pubertal transition in 8-9 year old children
Presented at the 14th Annual Conference of the Australian and New Zealand Academy of Eating Disorders, Christchurch, New Zealand.

Publications

Adrenarche and the emotional and behavioral problems of late childhood
Mundy et al. (2015). Adrenarche and the emotional and behavioral problems of late childhood. Journal of Adolescent Health, 57(6), 608-616.
Mental and behavioral disorders increase in prevalence with the passage through puberty. Yet the first symptoms for many children emerge between seven and 11 years, before the pubertal rise in gonadal hormones. A possibility that symptom onset may be linked to the adrenarchal rise in androgens has been little explored.
The Childhood to Adolescence Transition Study recruited a stratified random sample of 1,239 eight–nine year olds from primary schools in Melbourne, Australia. Saliva samples were assayed for dehydroepiandrosterone, dehydroepiandrosterone-sulphate (DHEA-S), and testosterone. Emotional and behavioral problems were assessed through parental report on the Strengths and Difficulties Questionnaire.
In males, high levels of all androgens were associated with greater total difficulties and peer problems. Higher dehydroepiandrosterone and testosterone were associated with emotional symptoms and DHEA-S with conduct problems. In females, DHEA-S was associated with peer problems.
In late childhood, androgens are associated with emotional and behavioral problems in males, raising a possibility that the adrenarchal transition plays a contributing role. If so, the late primary school years may prove to be an important phase for preventing the onset of mental health and behavioral problems in boys.

Reduced frontal white matter volume in children with early onset of adrenarche
Klauser et al. (2015). Reduced frontal white matter volume in children with early onset of adrenarche. Psychoneuroendocrinology, 52, 111-118.
While there is growing evidence that puberty affects brain development, very little is known about the structural brain changes associated with dehydroepiandrosterone (DHEA), an adrenal hormone that exhibits dramatic increases during adrenarche, the earliest phase of puberty. Moreover, no research has investigated whether relatively early exposure to DHEA (i.e., early adrenarche) during this period is associated with differences in brain structure. We ran a whole-brain voxel-based morphometry analysis on T1-weighted magnetic resonance imaging brain scans to compare gray (GMV) and white matter volumes (WMV) between children experiencing relatively early (n = 41) vs. relatively late (n = 44) adrenarche. We also investigated the correlations between GMV or WMV and DHEA levels, and finally, tested for sex differences in group and correlation analyses. We observed reduced frontal WMV in a cluster located on the left corona radiata in children experiencing earlier adrenarche. In addition, WMV in this area was negatively correlated with DHEA levels. We did not observe any effect of gender in both the group and the correlation analyses. Early onset of adrenarche (as defined by relatively early exposure to DHEA) may be associated with differences in the development of frontal white matter tracts.

Associations between early adrenarche, affective brain function and mental health in children
Whittle, et al. (2015). Associations between early adrenarche, affective brain function and mental health in children. Social cognitive and affective neuroscience, 10(9), 1282-1290.
Early timing of adrenarche, associated with relatively high levels of Dehydroepiandrosterone (DHEA) in children, has been associated with mental health and behavioral problems. However, little is known about effects of adreneracheal timing on brain function. The aim of this study was to investigate the effects of early adrenarche (defined by high DHEA levels independent of age) on affective brain function and symptoms of psychopathology in late childhood (N = 83, 43 females, M age 9.53 years, s.d. 0.34 years). Results showed that higher DHEA levels were associated with decreased affect-related brain activity (i) in the mid-cingulate cortex in the whole sample, and (ii) in a number of cortical and subcortical regions in female but not male children. Higher DHEA levels were also associated with increased externalizing symptoms in females, an association that was partly mediated by posterior insula activation to happy facial expressions. These results suggest that timing of adrenarche is an important moderator of affect-related brain function, and that this may be one mechanism linking early adrenarche to psychopathology.

Presentations

Bullying and academic performance in primary school children
Presented at the Society for Mental Health Research Conference, Brisbane, Australia.

The Childhood to Adolescence Transition Study (CATS): The Middle Years – A Foundation for Future Health and Wellbeing
Presented at the Youth Health Conference, Melbourne, Australia.

Media use and emotional and behavioural problems in children
Presented at the Society for Research in Child Development Conference, Philadelphia, USA.

Publications

Study protocol: imaging brain development in the childhood to adolescence transition study (iCATS)
Simmons et al. (2014). Study protocol: imaging brain development in the childhood to adolescence transition study (iCATS). BMC Pediatrics, 14(1), 115.
Puberty is a critical developmental phase in physical, reproductive and socio-emotional maturation that is associated with the period of peak onset for psychopathology. Puberty also drives significant changes in brain development and function. Research to date has focused on gonadarche, driven by the hypothalamic-pituitary-gonadal axis, and yet increasing evidence suggests that the earlier pubertal stage of adrenarche, driven by the hypothalamic-pituitary-adrenal axis, may play a critical role in both brain development and increased risk for disorder. We have established a unique cohort of children who differ in their exposure to adrenarcheal hormones. This presents a unique opportunity to examine the influence of adrenarcheal timing on brain structural and functional development, and subsequent health outcomes. The primary objective of the study is to explore the hypothesis that patterns of structural and functional brain development will mediate the relationship between adrenarcheal timing and indices of affect, self-regulation, and mental health symptoms collected across time (and therefore years of development).
Children were recruited based upon earlier or later timing of adrenarche, from a larger cohort, with 128 children (68 female; M age 9.51 years) and one of their parents taking part. Children completed brain MRI structural and functional sequences, provided saliva samples for adrenarcheal hormones and immune biomarkers, hair for long-term cortisol levels, and completed questionnaires, anthropometric measures and an IQ test. Parents completed questionnaires reporting on child behaviour, development, health, traumatic events, and parental report of family environment and parenting style.
This study, by examining the neurobiological and behavioural consequences of relatively early and late exposure to adrenarche, has the potential to significantly impact our understanding of pubertal risk processes.

Presentations

Academic performance in 8-9 year old children with common emotional and behavioural problems
Presented at the Society for Mental Health Research Conference, Adelaide, Australia.

Publications

Study Protocol: the Childhood to Adolescence Transition Study (CATS)
Mundy et al. (2013). Study Protocol: the Childhood to Adolescence Transition Study (CATS). BMC Pediatrics, 13(160), 1-13.
Puberty is a multifaceted developmental process that begins in late-childhood with a cascade of endocrine changes that ultimately lead to sexual maturation and reproductive capability. The transition through puberty is marked by an increased risk for the onset of a range of health problems, particularly those related to the control of behaviour and emotion. Early onset puberty is associated with a greater risk of cancers of the reproductive tract and cardiovascular disease. Previous studies have had methodological limitations and have tended to view puberty as a unitary process, with little distinction between adrenarche, gonadarche and linear growth. The Childhood to Adolescence Transition Study (CATS) aims to prospectively examine associations between the timing and stage of the different hormonally-mediated changes, as well as the onset and course of common health and behavioural problems that emerge in the transition from childhood to adolescence. The initial focus of CATS is on adrenarche, the first hormonal process in the pubertal cascade, which begins for most children at around 8 years of age.
CATS is a longitudinal population-based cohort study. All Grade 3 students (8–9 years of age) from a stratified cluster sample of schools in Melbourne, Australia were invited to take part. In total, 1239 students and a parent/guardian were recruited to participate in the study. Measures are repeated annually and comprise student, parent and teacher questionnaires, and student anthropometric measurements. A saliva sample was collected from students at baseline and will be repeated at later waves, with the primary purpose of measuring hormonal indices of adrenarche and gonadarche.
CATS is uniquely placed to capture biological and phenotypic indices of the pubertal process from its earliest manifestations, together with anthropometric measures and assessment of child health and development. The cohort will provide rich detail of the development, lifestyle, external circumstances and health of children during the transition from childhood through to adolescence. Baseline associations between the hormonal measures and measures of mental health and behaviour will initially be examined cross-sectionally, and then in later waves longitudinally. CATS will make a unique contribution to the understanding of adrenarche and puberty in children’s health and development.

Presentations

Behavioural and emotional problems during early puberty
Presented at the International Congress of Pediatrics Conference, Melbourne, Australia.