Author name cluster

Sarah Whittle

Possible papers associated with this exact author name in Arrow. This page groups case-insensitive exact name matches and is not a full identity disambiguation profile.

9 papers

1 author row

YNIMG Journal 2021 Journal Article

A longitudinal analysis of puberty‐related cortical development

Nandita Vijayakumar
George J. Youssef
Nicholas B Allen
Vicki Anderson
Daryl Efron
Philip Hazell
Lisa Mundy
Jan M Nicholson

The brain undergoes extensive structural changes during adolescence, concurrent to puberty-related physical and hormonal changes. While animal research suggests these biological processes are related to one another, our knowledge of brain development in humans is largely based on age-related processes. Thus, the current study characterized puberty-related changes in human brain structure, by combining data from two longitudinal neuroimaging cohorts. Beyond normative changes in cortical thickness, we examined whether individual differences in the rate of pubertal maturation (or "pubertal tempo") was associated with variations in cortical trajectories. Participants (N = 192; scans = 366) completed up to three waves of MRI assessments between 8.5 and 14.5 years of age, as well as questionnaire assessments of pubertal stage at each wave. Generalized additive mixture models were used to characterize trajectories of cortical development. Results revealed widespread linear puberty-related changes across much of the cortex. Many of these changes, particularly within the frontal and parietal cortices, were independent of age-related development. Males exhibiting faster pubertal tempo demonstrated greater thinning in the precuneus and frontal cortices than same-aged and -sex peers. Findings suggest that the unique influence of puberty on cortical development may be more extensive than previously identified, and also emphasize important individual differences in the coupling of these developmental processes.

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YNIMG Journal 2020 Journal Article

Adrenarcheal hormone-related development of white matter during late childhood

Marjolein E.A. Barendse
Julian G. Simmons
Robert E. Smith
Marc L. Seal
Sarah Whittle

The aim of the current study was to longitudinally examine how adrenarcheal hormones influence the development of white matter structure from age 8.5 to 10 years. Participants were 120 children (66 female; mean age 8.45 years at Time 1 and 9.97 years at Time 2) who completed two diffusion-weighted imaging scans 1.5 years apart. Morning saliva samples were taken at both assessment time points to measure levels of dehydroepiandrosterone (DHEA), its sulphate (DHEAS), and testosterone. Fixel-based analysis was performed to examine how changes in white matter fibre density (FD) and cross-section (FC) over time were associated with initial levels of hormones, and changes in hormone levels over time. Both FD and FC increased over time in a wide range of white matter tracts. Increases in testosterone over time were related to relatively weaker increases in FC in the inferior fronto-occipital fasciculus. Levels and change in DHEA and DHEAS were not related to FD or FC changes. The results demonstrated development of white matter fibre density and cross-section from age 8.5 to 10 years. Changes in adrenarcheal hormone levels showed limited, localized associations with development of white matter FC. Future research should examine the relevance of adrenarcheal hormone-related white matter development for cognitive functioning; as well as directly compare analysis techniques of white matter structure.

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YNIMG Journal 2020 Journal Article

Pubertal hormones predict sex-specific trajectories of pituitary gland volume during the transition from childhood to adolescence

Sarah Whittle
Marjolein Barendse
Elena Pozzi
Nandita Vijayakumar
Julian G. Simmons

Pituitary gland volume (PGV) increases during childhood and adolescence in a sex-specific manner, and previous research suggests that puberty may be associated with PGV development. However, existing research to date has focused on sex hormones associated with gonadarche. Given the role of the pituitary gland in hypothalamic-pituitary-adrenal (HPA) axis function, the present study investigated associations between PGV development and HPA hormones that play a role in the earlier pubertal phase of adrenarche. Participants were a community sample of 249 children and early adolescents who participated in longitudinal brain imaging and pubertal assessments. Each participant provided data at one or two waves 1. 5–3 years apart, resulting in 409 datasets that covered the age range 8–13 years. PGV was estimated from T1-weighted Magnetic Resonance Imaging (MRI) scans, and dehydroepiandrosterone (DHEA), its sulfate (DHEA-S) and testosterone were measured from saliva. Estradiol was measured for a subset of females. Parents reported on physical pubertal development. Linear mixed modeling was used to investigate associations between age, pubertal measures and PGV development. DHEA, DHEA-S and testosterone (in addition to physical maturation) explained variance in PGV development over and above age, and in a sex-dependent fashion. In all cases, associations were stronger, or only present in females. Estradiol was associated with PGV in females, but this did not appear to account for adrenarcheal hormone effects. Our findings suggest a key role for the hormones of adrenarche, the first biochemical phase of puberty, in PGV development. Further research is required to understand the sex-specific role of adrenarcheal and gonadarcheal hormones on the PGV across development.

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YNIMG Journal 2019 Journal Article

Structural covariance networks in children and their associations with maternal behaviors

Sally Richmond
Richard Beare
Katherine A. Johnson
Nicholas B. Allen
Marc L. Seal
Sarah Whittle

There is a substantial body of research documenting the influence of early adverse experience on brain development. In contrast, relatively little attention has been directed toward the influence of ‘normative’ variation in parenting behaviors. This study investigated associations between parenting behaviors and structural brain networks, as measured by structural covariance, in a community sample of children. One hundred and forty-five typically developing 8-year-olds and their mothers completed questionnaire measures and two observed parent-child interaction tasks. Structural MRI scans were also obtained from the children. Structural covariance networks based on partial correlation between cortical thickness estimates were constructed, and estimates of efficiency were obtained using graph theoretical analysis. Associations between affective and communicative maternal behaviors and these network metrics were investigated. High levels of observed negative affective and communicative maternal behaviors were associated with decreased local efficiency, whereas high levels of positive affective maternal behaviors were associated with increased local efficiency. The regions implicated (including the cingulate cortex, temporal pole, and temporo-parietal junction) are thought to be involved in the processing of social information. Minimal support was found for an association between global efficiency and maternal behaviors. Our findings suggest that variations in parenting behaviors are associated with structural organization of socio-emotional brain networks in children.

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YNIMG Journal 2018 Journal Article

Development of subcortical volumes across adolescence in males and females: A multisample study of longitudinal changes

Megan M. Herting
Cory Johnson
Kathryn L. Mills
Nandita Vijayakumar
Meg Dennison
Chang Liu
Anne-Lise Goddings
Ronald E. Dahl

The developmental patterns of subcortical brain volumes in males and females observed in previous studies have been inconsistent. To help resolve these discrepancies, we examined developmental trajectories using three independent longitudinal samples of participants in the age-span of 8–22 years (total 216 participants and 467 scans). These datasets, including Pittsburgh (PIT; University of Pittsburgh, USA), NeuroCognitive Development (NCD; University of Oslo, Norway), and Orygen Adolescent Development Study (OADS; The University of Melbourne, Australia), span three countries and were analyzed together and in parallel using mixed-effects modeling with both generalized additive models and general linear models. For all regions and across all samples, males were found to have significantly larger volumes as compared to females, and significant sex differences were seen in age trajectories over time. However, direct comparison of sample trajectories and sex differences identified within samples were not consistent. The trajectories for the amygdala, putamen, and nucleus accumbens were most consistent between the three samples. Our results suggest that even after using similar preprocessing and analytic techniques, additional factors, such as image acquisition or sample composition may contribute to some of the discrepancies in sex specific patterns in subcortical brain changes across adolescence, and highlight region-specific variations in congruency of developmental trajectories.

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YNIMG Journal 2017 Journal Article

Cortico-amygdalar maturational coupling is associated with depressive symptom trajectories during adolescence

Nandita Vijayakumar
Nicholas B. Allen
Meg Dennison
Michelle L. Byrne
Julian G. Simmons
Sarah Whittle

Background Adolescence is characterized by increasing prevalence of depressive symptomatology, along with significant structural brain development. While much research has examined focal abnormalities in gray matter structure underlying depression, we employed a structural coupling approach to examine whether longitudinal associations between amygdala and cortical development (referred to as maturational coupling) was related to concurrent changes in depressive symptomatology during adolescence. Method 166 participants underwent up to three MRI scans (367 scans) between 11 and 20 years of age. Depressive symptoms were measured at three coinciding time points using the Center for Epidemiological Studies-Depression scale. Linear mixed models were employed to identify whether change in amygdala volume was related to development of cortical thickness, and if maturational coupling of these regions was related to changes in depressive symptomatology. Results Positive maturational coupling was identified between the right amygdala and (predominantly anterior) prefrontal cortex, as well as parts of the temporal cortices. Greater positive coupling of these regions was associated with reductions in depressive symptoms over time. Conclusions Findings highlight significant associations between cortico-amygdalar maturational coupling and the emergence of depressive symptoms during adolescence, suggesting that synchronous development of these regions might support more adaptive affect regulation and functioning.

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YNICL Journal 2015 Journal Article

Specific functional connectivity alterations of the dorsal striatum in young people with depression

Rebecca Kerestes
Ben J. Harrison
Orwa Dandash
Katerina Stephanou
Sarah Whittle
Jesus Pujol
Christopher G. Davey

BACKGROUND: Altered basal ganglia function has been implicated in the pathophysiology of youth Major Depressive Disorder (MDD). Studies have generally focused on characterizing abnormalities in ventral "affective" corticostriatal loops supporting emotional processes. Recent evidence however, has implicated alterations in functional connectivity of dorsal "cognitive" corticostriatal loops in youth MDD. The contribution of dorsal versus ventral corticostriatal alterations to the pathophysiology of youth MDD remains unclear. METHODS: Twenty-one medication-free patients with moderate-to-severe MDD between the ages of 15 and 24 years old were matched with 21 healthy control participants. Using resting-state functional connectivity magnetic resonance imaging we systematically investigated connectivity of eight dorsal and ventral subdivisions of the striatum. Voxelwise statistical maps of each subregion's connectivity with other brain areas were compared between the depressed and control groups. RESULTS: Depressed youths showed alterations in functional connectivity that were confined to the dorsal corticostriatal circuit. Compared to controls, depressed patients showed increased connectivity between the dorsal caudate nucleus and ventrolateral prefrontal cortex bilaterally. Increased depression severity correlated with the magnitude of dorsal caudate connectivity with the right dorsolateral prefrontal cortex. There were no significant between-group differences in connectivity of ventral striatal regions. CONCLUSIONS: The results provide evidence that alterations in corticostriatal connectivity are evident at the early stages of the illness and are not a result of antidepressant treatment. Increased connectivity between the dorsal caudate, which is usually associated with cognitive processes, and the more affectively related ventrolateral prefrontal cortex may reflect a compensatory mechanism for dysfunctional cognitive-emotional processing in youth depression.

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YNICL Journal 2014 Journal Article

Functional brain imaging studies of youth depression: A systematic review

Rebecca Kerestes
Christopher G. Davey
Katerina Stephanou
Sarah Whittle
Ben J. Harrison

BACKGROUND: There is growing interest in understanding the neurobiology of major depressive disorder (MDD) in youth, particularly in the context of neuroimaging studies. This systematic review provides a timely comprehensive account of the available functional magnetic resonance imaging (fMRI) literature in youth MDD. METHODS: A literature search was conducted using PubMED, PsycINFO and Science Direct databases, to identify fMRI studies in younger and older youth with MDD, spanning 13-18 and 19-25 years of age, respectively. RESULTS: Twenty-eight studies focusing on 5 functional imaging domains were identified, namely emotion processing, cognitive control, affective cognition, reward processing and resting-state functional connectivity. Elevated activity in "extended medial network" regions including the anterior cingulate, ventromedial and orbitofrontal cortices, as well as the amygdala was most consistently implicated across these five domains. For the most part, findings in younger adolescents did not differ from those in older youth; however a general comparison of findings in both groups compared to adults indicated differences in the domains of cognitive control and affective cognition. CONCLUSIONS: Youth MDD is characterized by abnormal activations in ventromedial frontal regions, the anterior cingulate and amygdala, which are broadly consistent with the implicated role of medial network regions in the pathophysiology of depression. Future longitudinal studies examining the effects of neurodevelopmental changes and pubertal maturation on brain systems implicated in youth MDD will provide a more comprehensive neurobiological model of youth depression.

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YNIMG Journal 2006 Journal Article

The influence of sulcal variability on morphometry of the human anterior cingulate and paracingulate cortex

Alex Fornito
Sarah Whittle
Stephen J. Wood
Dennis Velakoulis
Christos Pantelis
Murat Yücel

Human anterior cingulate (ACC) and paracingulate (PaC) cortices play an important role in cognitive and affective regulation and have been implicated in numerous psychiatric and neurological conditions. The region they comprise displays marked inter-individual variability in sulcal and gyral architecture, and although recent evidence suggests that this variability has functional significance, it is often ignored in automated and region-of-interest (ROI) morphometric investigations. This has lead to confounded interpretation of results and inconsistent findings across a number of studies and in a variety of clinical populations. In this paper, we present a reliable method for parcellating the dorsal, ventral, and subcallosal ACC and PaC that accounts for individual variation in the local cortical folding pattern. We also investigated the effect of one well characterized morphological variation, the incidence of the paracingulate sulcus (PCS), on regional volumes in 24 (12 male, 12 female) healthy participants. The presence of a PCS was shown to affect both ACC and PaC volumes, such that it was associated with an 88% increase in paracingulate cortex and a concomitant 39% decrease in cingulate cortex. These findings illustrate the potential confounds inherent in morphometric approaches that ignore or attempt to minimize inter-individual variations in sulcal and gyral anatomy and underscore the need to consider this variability when attempting to understand disease processes or characterize brain structure–function relationships.

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