PRISM :: Browsing by Author "Giesbrecht, Gerald"

Browsing by Author "Giesbrecht, Gerald"

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Open Access
Advancing Gestation Does Not Attenuate Biobehavioural Coherence Between Psychological Distress and Cortisol
(Biological Psychology, 2013-04) Giesbrecht, Gerald; Campbell, Tavis; Letourneau, Nicole; Kaplan, Bonnie; APrON Study Team
Background: Despite little evidence to suggest that HPA axis responses to psychological provocation are attenuated during pregnancy, it is widely held that dampening of the HPA axis response to psychological distress serves a protective function for the mother and fetus. The current study was designed to assess changes in biobehavioral coherence between psychological distress and cortisol over the course of pregnancy. Methods: Ambulatory assessment of ecologically relevant psychological distress and salivary cortisol were repeated in all three trimesters for 82 pregnant women. Samples were collected 5 times per day over the course of 2 days in each trimester. Results: Psychological distress and cortisol were positively associated, β = .024, p < .01, indicating that increases in psychological distress were associated with increases in cortisol. Gestational age did not moderate this association, β = .0009, p = .13, suggesting that negative psychological experiences remain potent stimuli for the HPA axis during pregnancy. Conclusion: Biobehavioral coherence between ecologically relevant experiences of psychological distress and cortisol is not attenuated with advancing gestation.
Open Access
Affective Experience in Ecologically Relevant Contexts is Dynamic, and Not Progressively Attenuated During Pregnancy
(Archives of Women's Mental Health, 2012-08) Giesbrecht, Gerald; Letourneau, Nicole; Campbell, Tavis; Kaplan, Bonnie; APrON Study Team
Pregnancy is thought to diminish a woman’s appraisals of and affective responses to stressors. To examine this assumption, we used an electronic diary and an ecological momentary assessment strategy to record women’s (n=85) experiences of positive and negative affect five times each day over two days within each trimester of pregnancy. Women also completed the Edinburgh Postnatal Depression Scale each trimester. Multi-level modeling indicated non-linear patterns for both positive and negative affect that differed by level of depressive symptoms. The findings suggest that changes in psychological experience over the course of pregnancy are dynamic and not progressively attenuated.
Open Access
The Alberta Pregnancy Outcomes and Nutrition (APrON) cohort study: rationale and methods
(Maternal & Child Nutrition, 2014-01) Kaplan, Bonnie; Giesbrecht, Gerald; Leung, Brenda; Field, Catherine; Dewey, Deborah; Bell, Rhonda; Manca, Donna; O'Beirne, Maeve; Johnston, David; Pop, Victor; Singhal, Nalini; Gagnon, Lisa; Bernier, Francois; Eliasziw, Misha; McCargar, Linda; Kooistra, Libbe; Farmer, Anna; Cantell, Marja; Goonewardene, Laki; Casey, Linda; Letourneau, Nicole; Martin, Jonathan; APrON Study Team
The Alberta Pregnancy Outcomes and Nutrition (APrON) study is an ongoing prospective cohort study that recruits pregnant women early in pregnancy and, as of 2012, is following up their infants to 3 years of age. It has currently enrolled approximately 5000 Canadians (2000 pregnant women, their offspring and many of their partners).The primary aims of the APrON study were to determine the relationships between maternal nutrient intake and status, before, during and after gestation, and (1) maternal mood; (2) birth and obstetric outcomes; and (3) infant neurodevelopment. We have collected comprehensive maternal nutrition, anthropometric, biological and mental health data at multiple points in the pregnancy and the post-partum period, as well as obstetrical, birth, health and neurodevelopmental outcomes of these pregnancies. The study continues to follow the infants through to 36 months of age.The current report describes the study design and methods, and findings of some pilot work. The APrON study is a significant resource with opportunities for collaboration.
Open Access
The anger-distress model of temper tantrums: associations with emotional reactivity and emotional competence.
(Wiley, 2010-04-01) Giesbrecht, Gerald; Miller, Michael, R.; Müller, Ulrich
The goals of this investigation were (a) to assess the structural validity of the anger-distress model of temper tantrums, and (b) to examine the associations among temper tantrums, emotional reactivity and emotional competence in a community sample of preschoolers. A parent-report measure, the Temper Tantrum Grid, was used to measure the frequency of common tantrum behaviours. Laboratory and parent report measures of emotional reactivity and emotional competence were administered. Confirmatory factor analysis supported the proposal that anger and distress are separate but overlapping tantrum processes. Correlation analyses showed that temper tantrum anger and distress were related to emotional reactivity and emotional competence. There was no evidence to support the notion that emotional competence moderated the effect of emotional reactivity on temper tantrums. In contrast, emotional competence was a significant mediator of the association between emotional reactivity and temper tantrums. Overall, the results support the anger-distress model of temper tantrums. The findings suggest that children’s temper tantrums are systematically related to the overall organization of emotion and behaviour in preschool children.
Open Access
The anger–distress model of temper tantrums: associations with emotional reactivity and emotional competence
(Infant and Child Development, 2010) Giesbrecht, Gerald; Miller, Michael; Müller, Ulrich
The goals of this investigation were (a) to assess the structural validity of the anger-distress model of temper tantrums, and (b) to examine the associations among temper tantrums, emotional reactivity and emotional competence in a community sample of preschoolers. A parent-report measure, the Temper Tantrum Grid, was used to measure the frequency of common tantrum behaviours. Laboratory and parent report measures of emotional reactivity and emotional competence were administered. Confirmatory factor analysis supported the proposal that anger and distress are separate but overlapping tantrum processes. Correlation analyses showed that temper tantrum anger and distress were related to emotional reactivity and emotional competence. There was no evidence to support the notion that emotional competence moderated the effect of emotional reactivity on temper tantrums. In contrast, emotional competence was a significant mediator of the association between emotional reactivity and temper tantrums. Overall, the results support the anger-distress model of temper tantrums. The findings suggest that children’s temper tantrums are systematically related to the overall organization of emotion and behaviour in preschool children.
Open Access
Associations Between Screen Time and Child Internalizing and Externalizing Behaviour Problems: A Meta-Analysis
(2021-08-19) Eirich, Rachel; Madigan, Sheri; Tomfohr, Lianne; Giesbrecht, Gerald; Climie, Emma
Background: Research on the effects of screen time on child outcomes has increased exponentially in response to the ubiquity of digital media. However, due to mixed findings, significant debate exists as to whether screen time is associated with problematic child outcomes, including internalizing and externalizing problems. It is important to understand the methodological differences that may be contributing to heterogeneity in findings and the possible risks and benefits of screen time to inform parents, clinicians, policy-makers, and future research. Objectives: To 1) meta-analytically determine the association between screen time (i.e., duration of use) and child externalizing and internalizing problems; 2) identify moderators that may contribute to discrepancies in the literature and point to areas for methodological improvement in future research. Method: Electronic searches were conducted in MEDLINE, Embase, and PsycINFO in June of 2019 and 22,528 non-duplicate articles were identified and screened for inclusion. Quantity of screen time was defined as the duration of time children spend viewing screens (e.g., television, tablets, video games, and/or computers, etc.). Child behaviour problems included externalizing (e.g., aggression, hyperactivity) and/or internalizing (e.g., depression, anxiety) behavioural symptoms or clinical diagnoses. Results: After screening all abstracts for inclusion, 434 full-text articles were assessed for eligibility and a total of 64 studies (with 74 unique samples; 85,225 participants) met all inclusion criteria. Results revealed that screen time was associated with more externalizing problems (k = 72, r = 0.12; 95% CI [0.10, 0.14]). Moderator analyses suggested that effect sizes were larger for males, in older studies, in studies examining aggression (vs. hyperactivity/inattention). Effect sizes were larger when the screen time informant was the child versus the parent. A separate meta-analysis revealed that screen time was also associated with more internalizing problems (k = 26, r = 0.07, 95% CI [0.04, 0.11]) and moderator analyses suggested that effect sizes were larger when the screen time informant was the child (vs. parent). Conclusions: These meta-analyses support small but significant associations between screen time and children’s behaviour problems. Methodological differences across studies were one of the most common contributors to mixed findings in the literature.
Open Access
Bridging the Gap - Exploring the Role of Cortisol on The Effects of Prenatal Depression on Child Neurocognition
(2022-08-19) Cattani, Danielle; Giesbrecht, Gerald; Lebel, Catherine; Campbell, Tavis
Prenatal depression is a potentially debilitating experience that can affect both birthing parent and child. The current study investigates the role of cortisol, a hormone well-known for its involvement in the stress response, in the association between prenatal depression and child neurocognitive outcomes. Specifically, we assessed child executive function and cortical thickness in the right frontal and prefrontal cortices. Pregnant participants completed the Edinburgh Postnatal Depression Scale (EPDS) to assess prenatal depression, and we examined prenatal cortisol using salivary cortisol samples. Children completed six executive function tasks spanning the three domains of executive functioning and underwent magnetic resonance imaging to assess their cortical thickness. Our results indicate that prenatal depression during pregnancy, particularly early pregnancy, has the potential to adversely impact mental flexibility in children ages 3 – 4 years. Furthermore, an elevated prenatal cortisol awakening response (CAR) was related to timing-specific and region-specific cortical thinning in the right frontal cortex of children ages 3 – 7 years. Lastly, increased CAR in the third trimester was associated with better mental flexibility outcomes. Prenatal cortisol did not mediate the relationship between prenatal depression and child cortical thickness or executive function outcomes in our sample. Future research directions are discussed. Our study emphasizes the importance of caring for prenatal mental health in improving outcomes for child neurocognition.
Open Access
The Buffering Effect of Social Support on Hypothalamic-Pituitary-Adrenal Axis Function During Pregnancy
(Psychosomatic Medicine, 2013) Giesbrecht, Gerald; Poole, Julia; Letourneau, Nicole; Campbell, Tavis; Kaplan, Bonnie; APrON Study Team
Objective: Recent studies suggest that effective social support during pregnancy may buffer adverse effects of maternal psychological distress on fetal development. The mechanisms whereby social support confers this protective advantage, however, remain to be clarified. The aim of this study was to assess whether individual differences in social support alter the co-variation of psychological distress and cortisol during pregnancy. Methods: Eighty two pregnant women’s psychological distress and cortisol were prospectively assessed in all three trimesters using an ecological momentary assessment strategy. Appraisal of partner social support was assessed in each trimester via the Social Support Effectiveness questionnaire. Results: In multilevel analysis, ambulatory assessments of psychological distress during pregnancy were associated with elevated cortisol levels, unstandardized β = .023, p < .001. Consistent with the stress buffering hypothesis, social support moderated the association between psychological distress and cortisol, unstandardized β = -.001, p = .039, such that the co-variation of psychological distress and cortisol increased with decreases in effective social support. The effect of social support for women with the most effective social support was a 50.4% reduction in the mean effect of distress on cortisol and a 2.3 fold increase in this effect for women with the least effective social support scores. Conclusions: Pregnant women receiving inadequate social support secrete higher levels of cortisol in response to psychological distress as compared to women receiving effective social support. Social support during pregnancy may be beneficial because it decreases biological sensitivity to psychological distress, potentially shielding the fetus from the harmful effects of stress-related increases in cortisol.
Open Access
Changes in Student Mental Health and Adaptive Functioning During the COVID-19 Pandemic: Does Age Matter
(2021-08-30) Williams, Sarah Ruth; Schwartz, Kelly; Adorjan, Michael; Giesbrecht, Gerald
The impact of the COVID-19 pandemic on the lives of individuals across the globe has been significant. One segment of the Canadian population that may be particularly vulnerable to the impact of the pandemic are adolescents. Due to the developmental tasks and formational experiences that characterize the adolescent period, a growing number of studies have set out to investigate the potential effect that the pandemic may be having on youth, particularly as the pandemic effects pertain to their mental health. Almost a year and a half later, there are questions that still remain unanswered. As such, the current study sought to better understand adolescent mental health and adaptive functioning during this time and to determine whether there are age differences both cross-sectionally and across time. The current study followed a sample of adolescents from four metropolitan school divisions at two time points: September 2020 (N=2397) and December 2020 (N=1689). Participants completed the Behavior Intervention Monitoring Assessment System (BIMAS-2) measure, a 34-item universal screening measure of conduct problems, negative affect, and cognitive/attention difficulties as well as social and academic functioning. To better understand adolescents’ pandemic-related concerns, participants also completed an 11-item COVID-concern scale. Results indicated that, although mental health and COVID-related concerns are increasing and adaptive functioning is decreasing during the first four months of the school year, that adolescents’ experience during COVID-19 differs depending on their age. Older adolescents reported higher negative affect and cognition/attention difficulties while younger adolescents reported higher conduct and academic functioning. Moving forward, these results can help to inform development of programs and strategies for adolescents as they continue to navigate new experiences within the context of COVID-19.
Open Access
The Chemo-Gut Project: Investigating the Effects of Cancer Treatment on Gut Microbiota, Gastrointestinal and Psychosocial Health in Cancer Survivors
(2022-04) Deleemans, Julie; Carlson, Linda; Reimer, Raylene; Schulte, Fiona; Noel, Melanie; Giesbrecht, Gerald
Introduction: Cancer treatments such as chemotherapy adversely affect the gut microbiota, gastrointestinal (GI) and psychosocial health. However, it is unknown whether changes in the gut microbiota persist in the long-term, and if this may be related to GI and psychosocial symptoms. This work investigated the longer-term effects of cancer treatments on the gut microbiota, psychosocial and GI symptoms, and explored potential prebiotic and probiotic treatment options. Methods: A cross-sectional survey study with 317 cancer survivors examined characteristics of GI, physical and mental health outcomes, whether GI symptoms were associated with mental and physical health, and relationships between type of cancer treatment and these outcomes. A cross-sectional pilot study with 17 cancer survivors and 18 healthy volunteers investigated relationships between cancer treatment-related factors, gut microbiota, GI and psychosocial symptoms. A systematic review then evaluated the current literature on prebiotic and probiotic interventions used to treat GI and/or psychosocial symptoms in cancer patients and survivors. Results: Survivors in the survey study reported persistent GI symptoms, and 52% rated their GI symptom severity as moderate to extreme. Survivors reported poorer mental and physical health compared to PROMIS normative scores, and higher GI symptom severity was associated with worse mental and physical health. Survivors in the pilot study had more GI symptoms, poorer psychosocial health, and significantly greater abundance of Selenomondales, Veilloneliaceae, and Intestinibacter. In survivors, Lachnospiraceae, Ruminococcaceae and Intestinibacter correlated with psychosocial symptoms. Survivors ≤6 months post-treatment had lower alpha diversity than survivors >6 months post-treatment and healthy controls. Our systematic review found that probiotics were associated with improvements in several GI symptoms, especially diarrhea. However, improvements in anxiety, depression, fatigue, and QOL were only found in cancer survivors who received probiotic intervention. Conclusion: GI symptoms may persist for years after anti-cancer therapies have ended, and are associated with poorer physical and psychosocial health. In the first 6 months after cancer treatment gut microbiota alpha diversity is lowest, and specific bacteria may impact survivors’ psychosocial symptoms. Probiotics may help to alleviate some GI and psychosocial symptoms. Interventions combining dietary treatment with psychosocial interventions may be crucial for optimizing patient outcomes.
Open Access
Child and Context Characteristics in Trajectories of Physical and Relational Victimization among Early Elementary School Children
(Development and Psychopathology, 2010) Giesbrecht, Gerald; Leadbeater, Bonnie; MacDonald, Stuart
Transactional models suggest that peer victimization results from both individual and context differences, and understanding these differences may point to important targets for prevention and interventions that reduce victimization. Multilevel modeling was used to examine within-person (aggression and emotional dysregulation), between-person (sex and age), and between-school (participation in a victimization prevention program) factors that influence changes in physical and relational victimization over the first three years of elementary school. Children (n=423) reported their experiences of peer victimization at entry into Grade 1 and at the end of Grade 1, Grade 2 and Grade 3. On average, trajectories of both physical and relational victimization declined. However, for individual children, teacher-rated aggression was associated with increases in physical and relational victimization, while emotional dysregulation was associated with attenuation of longitudinal declines in physical victimization and increases in relational victimization. Individual differences in sex and age at entry into Grade 1 did not significantly influence victimization trajectories over grades 1 to 3. Children who participated in the WITS® victimization prevention program showed significant declines in physical and relational victimization. Levels of victimization among non-participants remained stable. Implications of child and context characteristics for preventing peer victimization in elementary school are discussed.
Open Access
Cognitive and emotional aspects of self-regulation in preschoolers
(Cognitive Development, 2007) Liebermann, Dana; Giesbrecht, Gerald; Müller, Ulrich
The goal of the present study was to examine the contribution of executive function (EF) and social cognition to individual differences in emotion regulation (ER) in preschool children. Sixty 3-, 4-, and 5-year-old children were administered a battery of EF tasks, two theory of mind tasks, a measure of verbal ability, and an ER task. In addition, parents completed the Behavior Rating Inventory of Executive Functioning—Preschool Version (BRIEF-P). Performance on the theory of mind tasks as well as parental ratings of executive function was not related to performance on the ER task. However, a component of EF (i.e., inhibition) approached significance with children’s displays of positive behaviors during the ER task. Verbal ability was related to the regulation of positive but not negative emotions. Parental ratings of shifting accounted for a significant amount of variance in parental ratings of ER, even after controlling for verbal ability. The findings are discussed in the context of different conceptualizations of the developmental relation between ER and EF.
Open Access
The contribution of executive function and social understanding to preschoolers’ letter and math skills
(Cognitive Development, 2013) Miller, Michael; Müller, Ulrich; Giesbrecht, Gerald; Carpendale, Jeremy; Kerns, Kimberly
The influence of executive function and social understanding on letter and math skills was examined in 129 3–5-year-olds. Tasks were administered to measure working memory, inhibition, social understanding, letter and math skills, and vocabulary. Using latent variable analyses, multiple models were compared in order to examine the influence of executive function and social understanding on participants’ emerging academic skills. In the best-fitting model, working memory contributed to letter and math skills, over and above inhibition, social understanding, age, and vocabulary. Inhibition and social understanding did not uniquely contribute to letter and math skills, but significant relations were found among working memory, inhibition, and social understanding. Findings are discussed with respect to improving ways to examine the complex relations among preschoolers’ executive function, social understanding, and school readiness skills.
Open Access
Developmental Origins of Infant Emotion Regulation: Mediating and Moderating Effects of Infant Temperament and Maternal Sensitivity
(2015-09-23) Thomas, Jenna; Campbell, Tavis; Giesbrecht, Gerald
The current study examined perinatal factors that impact infant emotion regulation (ER) development. Prenatal depression, generalized anxiety, pregnancy-specific anxiety (PSA), and diurnal cortisol levels were assessed in 256 pregnant women in early and late pregnancy. Infant temperamental negativity was assessed at 3 months, and observational measures of infant ER during frustration and maternal sensitivity were assessed at 6 months. Results revealed that PSA had a positive direct effect on infant ER, which potentially indicated emotional over-regulation in these infants. PSA also had a negative indirect effect on infant ER through increased temperamental negativity, which was dependent on levels of maternal sensitivity. Specifically, infants with high negativity demonstrated emotional under-regulation, but only when their mother displayed low levels of sensitivity. The study identified two pathways by which PSA may result in long-term changes in infant emotional development. Implications for future research and intervention planning are discussed.
Open Access
Developmental origins of infant stress reactivity profiles: A multi-system approach
(Wiley, 2016-03-08) Giesbrecht, Gerald; Rash, Joshua, A.; Thomas, Jenna, C.; Campbell, Tavis, S.; Letourneau, Nicole; Granger, Douglas, A.
Background: This study tested the hypothesis that maternal physiological and psychological variables during pregnancy discriminate between theoretically informed infant stress reactivity profiles. Methods: The sample comprised 254 women and their infants. Maternal mood, salivary cortisol, respiratory sinus arrhythmia (RSA), and salivary α-amylase (sAA) were assessed at 15 and 32 weeks gestational age. Infant salivary cortisol, RSA, and sAA reactivity were assessed in response to a structured laboratory frustration task at 6-months of age. Infant responses were used to classify them into stress reactivity profiles using three different classification schemes: HPA-axis, autonomic, and multi-system. Discriminant function analyses evaluated the prenatal variables that best discriminated infant reactivity profiles within each classification scheme. Results: Maternal stress biomarkers, along with self-reported psychological distress during pregnancy discriminated between infant stress reactivity profiles. Conclusions: These results suggest that maternal psychological and physiological states during pregnancy have broad effects on the development of the infant stress response systems.
Open Access
The Effects of ‘Does Not Apply’ on Measurement of Temperament with the Infant Behavior Questionnaire-Revised: A Cautionary Tale for Very Young Infants
(Early Human Development, 2014-10) Giesbrecht, Gerald; Dewey, Deborah; APrON Study Team
Background: The Infant Behavior Questionnaire-Revised (IBQ-R) is a widely used parent report measure of infant temperament. Items marked 'does not apply' (NA) are treated as missing data when calculating scale scores, but the effect of this practice on assessment of infant temperament has not been reported. Aims: To determine the effect of NA responses on assessment of infant temperament and to evaluate the remedy offered by several missing data strategies. Study design: A prospective, community-based longitudinal cohort study. Subjects: 401 infants who were born >37 weeks of gestation. Outcome measures: Mothers completed the short form of the IBQ-R when infants were 3-months and 6-months of age. Results: The rate of NA responses at the 3-month assessment was three times as high (22%) as the rate at six months (7%). Internal consistency was appreciably reduced and scale means were inflated in the presence of NA responses, especially at 3-months. The total number of NA items endorsed by individual parents was associated with infant age and parity. None of the missing data strategies completely eliminated problems related to NA responses but the Expectation Maximization algorithm greatly reduced these problems. Conclusions: The findings suggest that researchers should exercise caution when interpreting results obtained from infants at 3 months of age. Careful selection of scales, selecting a full length version of the IBQ-R, and use of a modern missing data technique may help to maintain the quality of data obtained from very young infants.
Open Access
Evaluating treatments in health care: The instability of a one-legged stool
(BMC Medical Research Methodology, 2011) Kaplan, Bonnie; Giesbrecht, Gerald; Shannon, Scott; McLeod, Kevin
Background: Both scientists and the public routinely refer to randomized controlled trials (RCTs) as being the 'gold standard' of scientific evidence. Although there is no question that placebo-controlled RCTs play a significant role in the evaluation of new pharmaceutical treatments, especially when it is important to rule out placebo effects, they have many inherent limitations which constrain their ability to inform medical decision making. The purpose of this paper is to raise questions about over-reliance on RCTs and to point out an additional perspective for evaluating healthcare evidence, as embodied in the Hill criteria. The arguments presented here are generally relevant to all areas of health care, though mental health applications provide the primary context for this essay. Discussion: This article first traces the history of RCTs, and then evaluates five of their major limitations: they often lack external validity, they have the potential for increasing health risk in the general population, they are no less likely to overestimate treatment effects than many other methods, they make a relatively weak contribution to clinical practice, and they are excessively expensive (leading to several additional vulnerabilities in the quality of evidence produced). Next, the nine Hill criteria are presented and discussed as a richer approach to the evaluation of health care treatments. Reliance on these multi-faceted criteria requires more analytical thinking than simply examining RCT data, but will also enhance confidence in the evaluation of novel treatments. Summary: Excessive reliance on RCTs tends to stifle funding of other types of research, and publication of other forms of evidence. We call upon our research and clinical colleagues to consider additional methods of evaluating data, such as the Hill criteria. Over-reliance on RCTs is similar to resting all of health care evidence on a one-legged stool.
Open Access
Full-term deliveries without antecedent labor reveal sex differences in umbilical cord glucocorticoid concentrations.
(Elsevier, 2016-12) Giesbrecht, Gerald; Rash, Joshua, A.; Edwards, Heather, E.; Wynne-Edwards, Katherine, E.
Background: Previous studies have shown that pregnant women have higher salivary cortisol levels when the fetus is female. These findings suggest a basis for the sex differences observed in many offspring outcomes after exposure to in utero stress, but it is not known if fetal adrenal glucocorticoid synthesis differs by sex. Methods: Arterial and venous umbilical cord blood samples were collected immediately after scheduled cesarean delivery (n = 52, 25 female). Cortisol and corticosterone concentrations were quantified by liquid chromatography coupled to tandem mass spectrometry. Results: Sex differences were observed for fetal arterial and venous cortisol and venous corticosterone, with higher levels present when the fetus was female. However, sex differences were not observed for fetal synthesis of cortisol, suggesting that the fetus does not control the differences observed in cord blood glucocorticoids. Conclusions: The presence of sex differences in umbilical cord glucocorticoid concentrations in the absence of sex differences in glucocorticoid synthesis by the fetal adrenal gland suggests that these differences have a maternal or placental origin. Thus, the in utero glucocorticoids in circulation are sex-specific and may have developmental importance for sex differences in psychiatric and neurodevelopment disorders that display sex biases.
Open Access
How Do Interactions Between Early Caregiving Environment and Genes Influence Health and Behavior?
(Biological Research for Nursing, 2014) Letourneau, Nicole; Giesbrecht, Gerald; Bernier, Francois; Joschko, Justin
To promote optimal health and behavioral outcomes in children, nurses have long supported parents in providing the best possible care and nurturance to their offspring. A growing body of neuroscience research argues convincingly for the combined influences of genes and early caregiving on producing an individual’s unique health and behavioral phenotype. In this article, we systematically review studies that demonstrate the relationship between qualities of early caregiving and genetic propensity to health and behavioral outcomes. From an initial set of 255 articles, 24 articles met our inclusion criteria. The outcomes fall into four distinct groups: hypothalamic-pituitary-adrenal (HPA) response to stress, externalizing behavior, internalizing behavior, and disorganized attachment. In the articles, authors examined genes that code for the 5-hydroxy tryptamine (serotonin) transporter genes linked polymorphic region [5-HTTLPR] serotonin transporter promoter, D4 dopamine receptor, brain-derived neurotrophic factor, and monoamine oxidase A promoter. The reviewed studies suggest that the effect of the early rearing environment on gene expression relates mainly to HPA response to stress, whereas interactions between genes and caregiving mainly relate to behavior and attachment. Findings have implications for nurses focused on advocacy, prevention, and intervention to support the healthy development of children in families faced with adversity.
Open Access
Impact of Alterations to Early Life Microbiota (Antibiotics, Prebiotics, and C-Section) on Body Weight and Brain Development
(2021-09-21) Cho, Nicole A; Reimer, Raylene A.; Mychasiuk, Richelle; Sharkey, Keith A; Giesbrecht, Gerald
Background: Communication between the gut microbiota, gut, and brain is now known to influence behavior, metabolic health, and immunity. Foods that improve the composition of the gut microbiota as well as factors that can disrupt it during early development are of interest to investigate the origins of and possible therapeutics for chronic diseases like obesity and mood and neurodevelopmental disorders. Objective: This dissertation examines how early life perturbations to gut microbiota, such as maternal antibiotic use, prebiotic consumption, maternal obesity, and C-section (CS) alter microbial, metabolic, behavioral, and brain outcomes. Specifically, the objectives of this thesis were to: 1) assess the impact of CS in offspring of lean and obese dams on offspring obesity risk; 2) examine the impact of CS and maternal prebiotic intake on offspring microglia and neuron morphology; 3) determine the effects of maternal antibiotic/prebiotic intake on offspring behavior and microglia reactivity; 4) investigate the effects of maternal and child antibiotic use on BMI z-score and temperament in 3-year-old children in a clinical cohort.Methods: Animal studies were conducted in Sprague-Dawley rats or NIH Swiss mice. Clinical participant data was accessed from the Alberta Pregnancy and Nutrition Outcomes (APrON) study. Body composition was measured with dual x-ray absorptiometry (DXA). Elevated Plus Maze (EPM), Novel Context Mismatch (NCM), and Sucrose Preference Tests (SPT) were used to assess behavior. Microglia were analyzed using the expression of IBA-1. Gut microbiota was assessed using 16S rRNA gene sequencing, and tissue gene expression was measured using RT-PCR. Temperament data was assessed using the Child Behavior Questionnaire (CBQ).Results: The primary findings from our study objectives were: 1) CS-associated obesity risk in offspring is dependent on maternal obesity status; 2) Maternal prebiotic intake reverses CS-induced alterations to microglia; 3) Antibiotic-induced alterations to microglia are reversed by maternal prebiotic intake; 4) Maternal and child antibiotic use is associated with increased BMI z-score in children. Conclusion: Our results provide evidence that early-life microbial perturbations alter obesity risk and microglia activation. We also demonstrated the potential for prebiotics to reduce the neuroinflammation that could modulate the risk for mood and neuropsychiatric disorders.