Public Health Commons^™

Dhea: A Neglected Biological Signal That May Affect Fetal And Child Development, Natasha A. Bailey, Elysia Poggi Davis, Curt A. Sandman, Laura M. Glynn

Psychology Faculty Articles and Research

The stress-sensitive maternal hypothalamic–pituitary–adrenal (HPA) axis through the end-product cortisol, represents a primary pathway through which maternal experience shapes fetal development with long-term consequences for child neurodevelopment. However, there is another HPA axis end-product that has been widely ignored in the study of human pregnancy. The synthesis and release of dehydroepiandosterone (DHEA) is similar to cortisol, so it is a plausible, but neglected, biological signal that may influence fetal neurodevelopment. DHEA also may interact with cortisol to determine developmental outcomes. Surprisingly, there is virtually nothing known about human fetal exposure to prenatal maternal DHEA and offspring neurodevelopment. The current study …

Experiences Of Covid-19-Related Racism And Impact On Depression Trajectories Among Racially/Ethnically Minoritized Adolescents, Sabrina R. Liu, Elysia Poggi Davis, Anton M. Palma, Hal S. Stern, Curt A. Sandman, Laura M. Glynn

Psychology Faculty Articles and Research

Purpose

In 2020, racially/ethnically minoritized (REMD) youth faced the “dual pandemics” of COVID-19 and racism, both significant stressors with potential for adverse mental health effects. The current study tested whether short- and long-term trajectories of depressive symptoms from before to during the COVID-19 pandemic differed between REMD adolescents who did and did not endorse exposure to COVID-19-era-related racism (i.e., racism stemming from conditions created or exacerbated by the COVID-19 pandemic).

Methods

A community sample of 100 REMD adolescents enrolled in an ongoing longitudinal study of mental health was assessed before and during the COVID-19 pandemic. Participants were 51% girls, mean …

Early Life Exposure To Unpredictable Parental Sensory Signals Shapes Cognitive Development Across Three Species, Elyssia Poggi Davis, Kari Mccormack, Hina Arora, Desiree Sharpe, Annabel K. Short, Jocelyne Bachevalier, Laura M. Glynn, Curt A. Sandman, Hal S. Stern, Mar Sanchez, Tallie Z. Baram

Psychology Faculty Articles and Research

Exposure to early life adversity has long term consequences on cognitive function. Most research has focused on understanding components of early life adversities that contribute to later risk, including poverty, trauma, maltreatment, and neglect. Whereas these factors, in the aggregate, explain a significant proportion of emotional and cognitive problems, there are serious gaps in our ability to identify potential mechanisms by which early life adversities might promote vulnerability or resilience. Here we discuss early life exposure to unpredictable signals from the caretaker as an understudied type of adversity that is amenable to prevention and intervention. We employ a translational approach …

Intergenerational Risk And Resilience Pathways From Discrimination And Acculturative Stress To Infant Mental Health, Sabrina R. Liu, Curt A. Sandman, Elyssia Poggi Davis, Laura M. Glynn

Psychology Faculty Articles and Research

Preconception and prenatal stress impact fetal and infant development, and women of color are disproportionately exposed to sociocultural stressors like discrimination and acculturative stress. However, few studies examine links between mothers’ exposure to these stressors and offspring mental health, or possible mitigating factors. Using linear regression, we tested associations between prenatally assessed maternal acculturative stress and discrimination on infant negative emotionality among 113 Latinx/Hispanic, Asian American, Black, and Multiethnic mothers and their children. Additionally, we tested interactions between stressors and potential pre- and postnatal resilience-promoting factors: community cohesion, social support, communalism, and parenting self-efficacy. Discrimination and acculturative stress were related …

The Acute And Persisting Impact Of Covid-19 On Trajectories Of Adolescent Depression: Sex Differences And Social Connectedness, Sabrina R. Liu, Elyssia Poggi Davis, Anton M. Palma, Curt A. Sandman, Laura M. Glynn

Psychology Faculty Articles and Research

Background

The COVID-19 era is a time of unprecedented stress, and there is widespread concern regarding its short- and long-term mental health impact. Adolescence is a sensitive period for the emergence of latent psychopathology vulnerabilities, often activated by environmental stressors. The present study examined COVID-19′s impact on adolescent depression and possible influences of different domains of social connectedness (loneliness, social media use, social video game time, degree of social activity participation).

Methods

A community sample of 175 adolescents (51% boys, mean age = 16.01 years) completed questionnaires once before and twice during the COVID-19 pandemic. Piecewise growth modeling examined the …

The Association Of Parent-Child Communication With Internet Addiction In Left-Behind Children In China: A Cross-Sectional Study, Jingjing Cai, Yun Wang, Feng Wang, Jingjing Lu, Lu Li, Xudong Zhou

Pharmacy Faculty Articles and Research

Objective: Internet addiction has emerged as a growing concern worldwide. This study aimed to compare the prevalence of Internet addiction between left-behind children (LBC) and non-left-behind children (non-LBC), and explore the role of paternal and maternal parent-child communication on LBC.

Methods: We conducted a cross-sectional survey in rural areas in Anhui, China. The complete data were available from 699 LBC and 740 non-LBC. Multivariable logistic regression was used to examine 1) whether LBC were more likely to develop Internet addiction, and 2) the association between parent-child communication and Internet addiction among LBC.

Results: LBC had a higher likelihood to report …

Oxytocin, Cortisol, And Cognitive Control During Acute And Naturalistic Stress, Shari Young Kuchenbecker, Sarah D. Pressman, Jared Celniker, Karen M. Grewen, Ken D. Sumida, Naveen Jonathan, Brendan Everett, George M. Slavich

Health Sciences and Kinesiology Faculty Articles

Although stress is a strong risk factor for poor health, especially for women, it remains unclear how stress affects the key neurohormones cortisol and oxytocin, which influence stress-related risk and resilience. Whereas cortisol mediates energy mobilization during stress, oxytocin has anti-inflammatory, anxiolytic, and analgesic effects that support social connection and survival across the lifespan. However, how these neurohormones interrelate and are associated with cognitive control of emotional information during stress remains unclear. To address these issues, we recruited 37 college-aged women (M_age = 19.19, SD = 1.58) and randomly assigned each to a one-hour experimental session consisting of …

Aberrant Maturation Of The Uncinate Fasciculus Follows Exposure To Unpredictable Patterns Of Maternal Signals, Steven J. Granger, Laura M. Glynn, Curt A. Sandman, Steven L. Small, Andre Obenaus, David B. Keator, Tallie Z. Baram, Hal S. Stern, Michael A. Yassa, Elyssia Poggi Davis

Psychology Faculty Articles and Research

Across species, unpredictable patterns of maternal behavior are emerging as novel predictors of aberrant cognitive and emotional outcomes later in life. In animal models, exposure to unpredictable patterns of maternal behavior alters brain circuit maturation and cognitive and emotional outcomes. However, whether exposure to such signals in humans alters the development of brain pathways is unknown. In mother–child dyads, we tested the hypothesis that exposure to more unpredictable maternal signals in infancy is associated with aberrant maturation of corticolimbic pathways. We focused on the uncinate fasciculus, the primary fiber bundle connecting the amygdala to the orbitofrontal cortex and a key …

Maternal Depressive Symptoms Predict General Liability In Child Psychopathology, Danielle A. Swales, Hannah R. Snyder, Benjamin L. Hankin, Curt A. Sandman, Laura M. Glynn, Elyssia Poggi Davis

Psychology Faculty Articles and Research

Objective: The current study examines how maternal depressive symptoms relate to child psychopathology when structured via the latent bifactor model of psychopathology, a new organizational structure of psychopathological symptoms consisting of a general common psychopathology factor (p-factor) and internalizing- and externalizing-specific risk.

Method: Maternal report of depressive symptoms (Beck Depression Inventory – II) and child psychopathological symptoms (Child Behavior Checklist and Children’s Behavior Questionnaire) were provided by 554 mother-child pairs. Children in the sample were 7.7 years old on average (SD = 1.35, range = 5–11 years), and were 49.8% female, 46% Latinx, and 67% …

Unpredictable Maternal Behavior Is Associated With A Blunted Infant Cortisol Response, Amanda N. Noroña-Zhou, Alyssa Morgan, Laura M. Glynn, Curt A. Sandman, Tallie Z. Baram, Hal S. Stern, Elyssia Poggi Davis

Psychology Faculty Articles and Research

Background

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is associated with poor physical and mental health. Early-life adversity may dysregulate cortisol response to subsequent stress. This study examines the association between patterns of maternal behavior and infant stress response to a challenge. Specifically, we test whether infant exposure to unpredictable maternal sensory signals is related to the cortisol response to a painful stressor.

Method

Participants were 102 mothers and their children enrolled in a longitudinal study. Patterns of maternal sensory signals were evaluated at 6 and 12 months during a 10-min mother–infant play episode. Entropy rate was calculated as a quantitative …

Across Continents And Demographics, Unpredictable Maternal Signals Are Associated With Children's Cognitive Function, Elyssia Poggi Davis, Riikka Korja, Linnea Karlsson, Laura Glynn, Curt A. Sandman, Brian Vegetabile, Eeva-Leena Kataja, Saara Nolvi, Eija Sinervä, Juho Pelto, Hasse Karlsson, Hal S. Stern, Tallie Z. Baram

Psychology Faculty Articles and Research

Background

Early life experiences have persisting influence on brain function throughout life. Maternal signals constitute a primary source of early life experiences, and their quantity and quality during sensitive developmental periods exert enduring effects on cognitive function and emotional and social behaviors. Here we examined if, in addition to established qualitative dimensions of maternal behavior during her interactions with her infant and child, patterns of maternal signals may contribute to the maturation of children's executive functions. We focused primarily on effortful control, a potent predictor of mental health outcomes later in life.

Methods

In two independent prospective cohorts in Turku, …

Parameterizing And Validating Existing Algorithms For Identifying Out-Of-Bed Time Using Hip-Worn Accelerometer Data From Older Women, John Belletierre, Yiliang Zhang, Vincent Berardi, Kelsie M. Full, Jacqueline Kerr, Michael J. Lamonte, Kelly R. Evenson, Melbourne Hovell, Andrea Z. Lacroix, Chongzhi Di

Psychology Faculty Articles and Research

Objective: To parameterize and validate two existing algorithms for identifying out-of-bed time using 24-hour hip-worn accelerometer data from older women. Approach: Overall, 628 women (80±6 years old) wore ActiGraph GT3X+ accelerometers 24 hours/day for up to 7 days and concurrently completed sleep-logs. Trained staff used a validated visual analysis protocol to measure in-bed periods on accelerometer tracings (criterion). The Tracy and McVeigh algorithms were adapted for optimal use in older adults. A training set of 314 women was used to choose two key thresholds by maximizing the sum of sensitivity and specificity for each algorithm and data (vertical axis, VA, …

Oxytocin Receptor Gene (Oxtr) And Father Support Interact To Predict Depressive Symptoms Postpartum, Parambir Bhatti, Taylor Delaney, Michael Poulin, Jennifer Hahn-Holbrook

Psychology Faculty Articles and Research

Postpartum depression (PPD) is a debilitating mental illness affecting approximately 13% of mothers after birth. Both genetic and psychosocial factors contribute to PPD risk, but very little is known about how these factors interact. We tested whether the rs53576 polymorphism in the oxytocin receptor (OXTR) gene accounts for variation in the impact of low social support as a risk factor for depression among mothers during the perinatal period. New mothers (N = 220) provided saliva or blood DNA samples and completed surveys assessing PPD symptoms and perceived social support. In a significant interaction, social support from the …

The Influence Of Unpredictable, Fragmented Parental Signals On The Developing Brain, Laura M. Glynn, Tallie Z. Baram

Psychology Faculty Articles and Research

Mental illnesses originate early in life, governed by environmental and genetic factors. Because parents are a dominant source of signals to the developing child, parental signals - beginning with maternal signals in utero - are primary contributors to children’s mental health. Existing literature on maternal signals has focused almost exclusively on their quality and valence (e.g. maternal depression, sensitivity). Here we identify a novel dimension of maternal signals: their patterns and especially their predictability/unpredictability, as an important determinant of children’s neurodevelopment. We find that unpredictable maternal mood and behavior presage risk for child and adolescent psychopathology. In experimental models, fragmented/unpredictable …

Prenatal Risk For Asd: Fetal Cortisol Exposure Predicts Child Autism-Spectrum-Disorder Symptoms, Sheena Ram, Mariann A. Howland, Curt A. Sandman, Elyssia Poggi Davis, Laura M. Glynn

Psychology Faculty Articles and Research

The etiology of autism spectrum disorder (ASD) is multifactorial, complex, and likely involves interactions among genetic, epigenetic, and environmental factors. With respect to environmental influences, a growing literature implicates intrauterine experiences in the origin of this pervasive developmental disorder. In this prospective longitudinal study, we examined the hypothesis that fetal exposure to maternal cortisol may confer ASD risk. In addition, because ASD is four times more prevalent in males than in females, and because sexually dimorphic responses to intrauterine experiences are commonly observed, we examined whether or not any associations differ by fetal sex. Maternal plasma cortisol was measured at …

Measuring Novel Antecedents Of Mental Illness: The Questionnaire Of Unpredictability In Childhood, Laura M. Glynn, Hal S. Stern, Mariann A. Howland, Victoria B. Risbrough, Dewleen G. Baker, Caroline M. Nievergelt, Tallie Z. Baram, Elysia P. Davis

Psychology Faculty Articles and Research

Increasing evidence indicates that, in addition to poverty, maternal depression, and other well-established factors, unpredictability of maternal and environmental signals early in life influences trajectories of brain development, determining risk for subsequent mental illness. However, whereas most risk factors for later vulnerability to mental illness are readily measured using existing, clinically available tools, there are no similar measures for assessing early-life unpredictability. Here we validate the Questionnaire of Unpredictability in Childhood (QUIC) and examine its associations with mental health in the context of other indicators of childhood adversity (e.g., traumatic life events, socioeconomic status, and parenting quality). The QUIC was …

Pregnancy Anxiety Predicts Shorter Gestation In Latina And Non-Latina White Women: The Role Of Placental Corticotrophin-Releasing Hormone, Isabel F. Ramos, Christine M. Guardino, Maxwell Mansolf, Laura M. Glynn, Curt A. Sandman, Calvin J. Hobel, Christine Dunkel Schetter

Psychology Faculty Articles and Research

Objective

Previous research has shown that a woman’s anxiety about her pregnancy predicts gestational length. Placental corticotrophin-releasing hormone (CRH) is a stress-responsive peptide proposed as a mechanism. We examined placental CRH as a physiological mediator of the association between pregnancy anxiety and gestational length in Latina and non-Latina White women to replicate evidence of associations between pregnancy anxiety, placental CRH and gestational length; to test whether placental CRH levels or changes mediate effects of pregnancy anxiety on gestational length; to examine ethnic differences in pregnancy anxiety, placental CRH, and gestational length; and to explore whether the effects of pregnancy anxiety …

Prompts To Increase Physical Activity At Points-Of-Choice Between Stairs And Escalators: What About Escalator Climbers?, John Belletierre, Ben Nguyen, Sandy Liles, Vincent Berardi, Marc A. Adams, Paddy Dempsey, Yael Benporat, Jacqueline Kerr, Andrea Z. Lacroix, Melbourne Hovell

Psychology Faculty Articles and Research

Since 1980, many studies have evaluated whether stair-use prompts increased physical activity by quantifying changes in stair use. To more completely evaluate changes in physical activity, this study addressed the often-overlooked assessment of climbing up escalators by evaluating the degree to which stair-use sign prompts increased active ascent—defined as stair use or escalator climbing. Over 5 months, at an airport stairs/escalator point of choice, we video-recorded passersby (N = 13,544) who ascended either stairs or escalators, on 10 days with signs and 10 days without signs. Ascenders using the stairs, standing on the escalator, and climbing the escalator were …

Maternal Programming: Application Of A Developmental Psychopathology Perspective, Laura M. Glynn, Mariann A. Howland, Molly Fox

Psychology Faculty Articles and Research

The fetal phase of life has long been recognized as a sensitive period of development. Here we posit that pregnancy represents a simultaneous sensitive period for the adult female with broad and persisting consequences for her health and development, including risk for psychopathology. In this review, we examine the transition to motherhood through the lens of developmental psychopathology. Specifically, we summarize the typical and atypical changes in brain and behavior that characterize the perinatal period. We highlight how the exceptional neuroplasticity exhibited by women during this life phase may account for increased vulnerability for psychopathology. Further, we discuss several modes …

Women’S Pregnancy Life History And Alzheimer’S Risk: Can Immunoregulation Explain The Link?, Molly Fox, Carlo Berzuini, Leslie A. Knapp, Laura M. Glynn

Psychology Faculty Articles and Research

Background:

Pregnancy is associated with improvement in immunoregulation that persists into the geriatric phase. Impaired immunoregulation is implicated in Alzheimer’s disease (AD) pathogenesis. Hence, we investigate the relationship between pregnancy and AD. Methods:

Cross-sectional cohort of British women (N = 95). Cox proportional hazards modeling assessed the putative effects of cumulative months pregnant on AD risk and the mutually adjusted effects of counts of first and third trimesters on AD risk. Results:

Cumulative number of months pregnant, was associated with lower AD risk (β = −1.90, exp(β) = 0.15, P = .02). Cumulative number of first trimesters …

Psychological Well-Being And Restorative Biological Processes: Hdl-C In Older English Adults, Jackie Soo, Laura D. Kubzansky, Ying Chen, Emily S. Zevon, Julia K. Boehm

Psychology Faculty Articles and Research

Rationale

Psychological well-being is associated with better cardiovascular health, but the underlying mechanisms are unclear.

Objective

This study investigates one possible mechanism by examining psychological well-being's prospective association with lipid levels, focusing on high-density lipoprotein cholesterol (HDL-C).

Methods

Participants were 4757 healthy men and women ages ≥50 from the English Longitudinal Study of Ageing with clinical data from three times, three to five years apart. Psychological well-being was assessed at baseline using the Control, Autonomy, Satisfaction, and Pleasure scale; HDL-C, triglycerides, and total cholesterol were assayed from blood samples. Descriptive statistics and linear mixed models were used to examine associations …

Economic And Health Predictors Of National Postpartum Depression Prevalence: A Systematic Review, Meta-Analysis And Meta-Regression Of 308 Studies From 56 Countries, Jennifer Hahn-Holbrook, Taylor Cornwell-Hinrichs, Itzel Anaya

Psychology Faculty Articles and Research

Background: Postpartum depression (PPD) poses a major global public health challenge. PPD is the most common complication associated with childbirth and exerts harmful effects on children. Although hundreds of PPD studies have been published, we lack accurate global or national PPD prevalence estimates and have no clear account of why PPD appears to vary so dramatically between nations. Accordingly, we conducted a meta-analysis to estimate the global and national prevalence of PPD and a meta-regression to identify economic, health, social, or policy factors associated with national PPD prevalence.

Methods: We conducted a systematic review of all papers reporting …

The Dynamics Of Stress And Fatigue Across Menopause: Attractors, Coupling, And Resilience, Lisa Taylor-Swanson, Alexander E. Wong, David Pincus, Jonathan E. Butner, Jennifer Hahn-Holbrook, Mary Koithan, Kathryn Wann, Nancy F. Woods

Psychology Faculty Articles and Research

Objective:

The objective of this study was to evaluate the regulatory dynamics between stress and fatigue experienced by women during the menopausal transition (MT) and early postmenopause (EPM). Fatigue and perceived stress are commonly experienced by women during the MT and EPM. We sought to discover relationships between these symptoms and to employ these symptoms as possible markers for resilience.

Methods:

Participants were drawn from the longitudinal Seattle Midlife Women's Health Study. Eligible women completed questionnaires on 60+ occasions (annual health reports and monthly health diaries) (n = 56 women). The total number of observations across the sample was 4,224. …

When Is Affect Variability Bad For Health? The Association Between Affect Variability And Immune Response To The Influenza Vaccination, Brooke N. Jenkins, John F. Hunter, Marie P. Cross, Amanda M. Acevedo, Sarah D. Pressman

Psychology Faculty Articles and Research

Objectives—This study addresses methodological and theoretical questions about the association between affect and physical health. Specifically, we examine the role of affect variability and its interaction with mean levels of affect to predict antibody (Ab) levels in response to an influenza vaccination.

Methods—Participants (N = 83) received the vaccination and completed daily diary measures of affect four times a day for 13 days. At one and four months post-vaccination, blood was collected from the participants to assess Ab levels.

Results—Findings indicate that affect variability and its interaction with mean levels of affect predict an individual’s immune response. …

Abnormal Dendritic Maturation Of Developing Cortical Neurons Exposed To Corticotropin Releasing Hormone (Crh): Insights Into Effects Of Prenatal Adversity?, Megan M. Curran, Curt A. Sandman, Elyssia Poggi Davis, Laura M. Glynn, Tallie Z. Baram

Psychology Faculty Articles and Research

Corticotropin releasing hormone (CRH) produced by the hypothalamus initiates the hypothalamic- pituitary-adrenal (HPA) axis, which regulates the body's stress response. CRH levels typically are undetectable in human plasma, but during pregnancy the primate placenta synthesizes and releases large amounts of CRH into both maternal and fetal circulations. Notably, placental CRH synthesis increases in response to maternal stress signals. There is evidence that human fetal exposure to high concentrations of placental CRH is associated with behavioral consequences during infancy and into childhood, however the direct effects on of the peptide on the human brain are unknown. In this study, we used …

Gestational Hormone Profiles Predict Human Maternal Behavior At 1-Year Postpartum, Laura M. Glynn, Elyssia Poggi Davis, Curt A. Sandman, Wendy A. Goldberg

Psychology Faculty Articles and Research

In many non-human species, including primates, gestational reproductive hormones play an essential role in the onset of maternal motivation and behaviors. We investigated the associations between prepartum estradiol and progesterone and maternal behavior at 1-year postpartum in 177 women. Blood was obtained at five gestational time points and an index of quality of maternal care was determined using a well-validated mother-child interaction protocol. Women who exhibited higher quality maternal care at 1-year postpartum were characterized by unique gestational profiles of estradiol, progesterone and the estrogen to progesterone ratio; specifically by slower accelerations and levels of these hormone trajectories beginning in …

Is Postpartum Depression A Disease Of Modern Civilization?, Jennifer Hahn-Holbrook, Martie Haselton

Psychology Faculty Articles and Research

Access to calorie-dense foods, medicine, and other comforts has made modern humans healthier than our prehistoric ancestors in many respects. However, the epidemics of obesity, diabetes, and cardiovascular disease suggest that there are also drawbacks to modern living. Here, we address the question of whether the dramatic cultural changes that have occurred over the past century have inflated rates of postpartum depression, adding postpartum depression to the list of diseases of modern civilization. We review evidence from cross-cultural, epidemiological, and experimental studies documenting associations between postpartum depression and modern patterns of early weaning, diets deficient in essential fatty acids, low …

Pregnancy Anxiety And Prenatal Cortisol Trajectories, Heidi S. Kane, Christine Dunkel Schetter, Laura M. Glynn, Calvin J. Hobel, Curt A. Sandman

Psychology Faculty Articles and Research

Pregnancy anxiety is a potent predictor of adverse birth and infant outcomes. The goal of the current study was to examine one potential mechanism whereby these effects may occur by testing associations between pregnancy anxiety and maternal salivary cortisol on 4 occasions during pregnancy in a sample of 448 women. Higher mean levels of pregnancy anxiety over the course of pregnancy predicted steeper increases in cortisol trajectories compared to lower pregnancy anxiety. Significant differences between cortisol trajectories emerged between 30 to 31 weeks of gestation. Results remained significant when adjusted for state anxiety and perceived stress. Neither changes in pregnancy …

Changes In Sleep Time And Sleep Quality Across The Ovulatory Cycle As A Function Of Fertility And Partner Attractiveness, Brooke N. Jenkins, Elizabeth G. Pillsworth, Aaron T. Goetz

Psychology Faculty Articles and Research

Research suggests that near ovulation women tend to consume fewer calories and engage in more physical activity; they are judged to be more attractive, express greater preferences for masculine and symmetrical men, and experience increases in sexual desire for men other than their primary partners. Some of these cycle phase shifts are moderated by partner attractiveness and interpreted as strategic responses to women’s current reproductive context. The present study investigated changes in sleep across the ovulatory cycle, based on the hypothesis that changes in sleep may reflect ancestral strategic shifts of time and energy toward reproductive activities. Participants completed a …

Human Milk Cortisol Is Associated With Infant Temperament, Katherine R. Grey, Elyssia Poggi Davis, Curt A. Sandman, Laura M. Glynn

Psychology Faculty Articles and Research

The implications of the biologically active elements in milk for the mammalian infant are largely unknown. Animal models demonstrate that transmission of glucocorticoids through milk influences behavior and modifies brain development in offspring. The aim of this study was to determine the relation between human milk cortisol levels and temperament of the breastfed infant. Fifty-two mother and infant pairs participated when the infants were three-months old. Milk cortisol levels were assessed and each mother completed the Infant Behavior Questionnaire (IBQ), a widely used parent-report measure of infant temperament. Analyses revealed a positive association between milk cortisol and the negative affectivity …