Childhood racial discrimination and adult allostatic load: The role of Indigenous cultural continuity in allostatic resiliency

Social Science & Medicine 241 (2019) 112564

Contents lists available at ScienceDirect

Social Science & Medicine journal homepage: www.elsevier.com/locate/socscimed

Childhood racial discrimination and adult allostatic load: The role of Indigenous cultural continuity in allostatic resiliency

T

Cheryl L. Curriea,∗, Jennifer L. Copelandb, Gerlinde A. Metzc a

Faculty of Health Sciences, University of Lethbridge, M3083 Markin Hall, 4401 University Drive, Lethbridge AB, T1K 3M4, Canada Department of Kinesiology and Physical Education, University of Lethbridge, Canada c Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, Canada b

A R T I C LE I N FO

A B S T R A C T

Keywords: Canada Discrimination Allostatic load Childhood Cultural continuity Indigenous

Objective: To examine the association between racial discrimination experienced in childhood on allostatic load (AL) in adulthood, and whether this association differed by cultural continuity among Indigenous adults. Method: Data were collected from Indigenous adults attending university in a small city in western Canada between 2015 and 2017 (N = 105). The frequency of childhood racial discrimination was measured using an item modified from the Experience of Discrimination Scale. AL was measured as a composite of 7 biomarkers assessing neuroendocrine, cardiovascular, metabolic, and immune system function. Cultural continuity was measured using the Vancouver Index Enculturation Scale. Bootstrapped linear regression models examined associations adjusted for confounders, with and without stratification by a dichotomized measure of Indigenous cultural continuity. Results: Most Indigenous adults (72.3%) experienced racial discrimination some or most of the time in childhood. The frequency of child discrimination was significantly associated with AL, explaining 11% of the variance in adult AL score after adjustment for age and income. In the high cultural continuity group, there was no association between child discrimination and adult AL. In the low cultural continuity group, child discrimination was significantly associated with AL, explaining 21% of the variance in adult AL score. Conclusion: Childhood racial discrimination may have a biological toll on adult health through altered activation of the stress response system which could, over time, exacerbate health inequities in this population. High Indigenous cultural continuity served as a resilience factor that buffered the adverse impacts of childhood discrimination on adult AL score.

1. Introduction The concept of race is based on the erroneous belief of meaningful genetic and biological differences between human groups based on a set of phenotypic characteristics, the salience of which shifts across place and time (Jackson and Weidman, 2004; Williams, 1997). Racism is an ideology that informs prejudicial attitudes and racial discrimination directed at those perceived to be part of stigmatized racial groups (Williams, 1997). Racism now widely recognized as a fundamental determinant of health for stigmatized groups, including Indigenous peoples (Cunningham and Paradies, 2013; Currie et al., 2015; Friborg et al., 2017; Paradies et al., 2015; Phelan and Link, 2015; Williams et al., 2019). To date, there has been limited information about the impacts that childhood racial discrimination may have on adult health within Indigenous populations. This examination is important given the

∗

long history in many colonized countries of separating Indigenous children from their families and placing them in residential boarding schools where they experienced ongoing racial discrimination. In Canada, residential schools operated for more than 150 years, the purpose of which was to “kill the Indian in the child” and force Indigenous children to assimilate into Western culture (Government of Canada, 2008). The Canadian Truth and Reconciliation Commission interviewed 7000 residential school survivors who described how teachers and church staff denigrated them for their Indigenous race, languages, cultural practices, and spiritual ways of knowing over many years (Sinclair, 2015). Although residential school systems have been dismantled, Indigenous children continue to experience high levels of discrimination in many colonized nations. A nationally representative study in Canada found Indigenous children reported the highest levels of unfair

Corresponding author. E-mail address: [email protected] (C.L. Currie).

https://doi.org/10.1016/j.socscimed.2019.112564 Received 12 October 2018; Received in revised form 31 August 2019; Accepted 20 September 2019 Available online 26 September 2019 0277-9536/ © 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/).

Social Science & Medicine 241 (2019) 112564

C.L. Currie, et al.

knowing” (Bastien, 2004). Indigenous scholars from our territory have published accounts of the powerful impacts that ongoing personal retraditionalization has had on their lives (Bastien, 2004; Hungry Wolf, 1980). This study used a participatory action research framework (McTaggert, 1991). We worked with an Indigenous Advisory Committee (IAC) made up of key Indigenous stakeholders from this urban area to define the concept of CC in ways that were appropriate for this location before data collection began. It was determined that CC would be defined as the degree to which people identify with, feel a sense of pride for, and integrate the values and norms of their Indigenous culture into their current lives (Ryder et al., 2000). We conceptualized CC using a resilience lens, which represents the ability to sustain normal functioning despite significant adversity or risks (Fletcher and Sarkar, 2013). Acting on a separate dimension from risk, resilience moderates the impact of a risk on an outcome (Johnson et al., 2011). From this perspective, risk and resilience are understood as bipolar dimensions; the inverse of each risk factor is a protective factor, and the inverse of each resilience factor is one that amplifies the effect on risk (Johnson et al., 2011). Thus, rather than being investigated as a correlate of an outcome, a resilience variable is examined as a factor that may attenuate the association between a risk and an outcome, often in a stratified analysis. CC has been shown to operate in both dimensions across a number of Indigenous populations. As a protective factor, Indigenous CC is associated with reduced health-risk behaviour, improved mental health, reduced suicide, and reduced chronic disease (Bals et al., 2010; Chandler and Lalonde, 1998; Currie et al., 2013; Oster et al., 2014; Shepherd et al., 2017b). As a resilience factor, Indigenous CC has been shown to buffer the impact of low educational attainment on substance misuse in an urban context (Currie et al., 2013). Pertinent to the present study, CC among the Indigenous Sami in Norway has been shown to buffer the impact of lifetime racial discrimination on mental distress (Friborg et al., 2017). We sought to build on these findings by examining whether CC buffered the impact of child racial discrimination on AL. In summary, the key objectives of this study were to: (1) examine the extent and nature of retrospectively reported child racial discrimination among Indigenous adults; (2) examine the ways in which child discrimination may be impacting health, operationalized through AL; and (3) to examine whether associations between child racial discrimination and AL were moderated by CC.

treatment in urban-based schools, and were more likely than nonIndigenous children to state they did not feel safe in these schools (Currie and Wild, 2012). A nationally representative study in Australia found Indigenous children reported the highest levels of bullying victimization and racial discrimination across ethnic groups in schools (Priest et al., 2016). Longitudinal research suggests both child and caregiver experiences of discrimination are detrimental to Indigenous children, with prolonged and more frequent exposures impacting multiple domains of functioning (Shepherd et al., 2017a). Biological embedding may play a role in these findings, given frequent exposure to stressors in early life has been shown to impact the development and functioning of vital organs, and contribute to systematic differences in health in later years (McEwen, 1998a; Shepherd et al., 2017 a,b). Emerging evidence also links child discrimination to changes in stress biology. Adam et al. (2015) found racial discrimination experienced over a 20-year period starting in grade 7 predicted a flatter adult diurnal cortisol slope, lower cortisol awakening response (CAR), and lower average cortisol across the waking day by age 32. These findings are an indicator of hypocortisolism – a pattern of low and less dynamic cortisol levels which reflect and contribute to stress-related dysregulation of central and peripheral circadian mechanisms, with downstream effects on multiple aspects of biology, behaviour, and health (Adam et al., 2017; Heim et al., 2000). In their study, Adam et al. (2017) found that most of the tendency toward hypocortisolism was driven by adolescent rather than adult experiences of discrimination, suggesting adolescence may be a more sensitive developmental period for the impacts of discrimination on stress biology. In the present study we went beyond a single marker to examine the impacts of child racial discrimination on adult stress biology using an allostatic load (AL) framework. AL describes the dysregulation that can occur from high, unremitting stress including hypoactive or hyperactive responses to stressors, an inability to turn off the stress response when it is no longer needed, and primary mediators that chronically deviate from their normal range (McEwen, 1998b). The latter influence secondary outcomes such as blood pressure and inflammation, which then go on to influence tertiary outcomes of morbidity and mortality (Beckie, 2012). Thus, high AL can be characterized to represent multisystem wear and tear on the body, physiologic dysregulation, and elevated disease risk. Adverse early life experiences have been shown to have a lasting impact on AL, with profound effects on human health over time (Castagné et al., 2018; Danese and McEwen, 2012; Juster et al., 2010; Solís et al., 2015), including effects that extend beyond a single generation among Indigenous peoples (Chief Moon-Riley et al., 2019). To date, a key longitudinal study has linked adolescent experiences of racial discrimination between 16 and 18 years of age to elevated AL at age 20 (Brody et al., 2014). The extent to which racial discrimination experienced over the course of childhood and adolescence may be associated with AL in adulthood is unknown and a focus of the present study.

2. Method 2.1. Sampling Working with the IAC it was determined we would recruit postsecondary students who self-identified as First Nations, Métis, Inuit or Indigenous. The last category is important as some Indigenous Canadians, while still defining themselves as Indigenous Persons, may not identify as First Nations if they were not born in a First Nations community, live in a city, and/or are no longer defined as having “Indian Status” under Canadian law due to colonial practices that removed the rights of Indigenous people (Government of Canada, 2018). University students were recommended by the IAC given many have overcome significant hardships to attend post-secondary education. Thus, it was suggested that this population would be a particularly good test of the hypothesis that racial discrimination could impact AL as this group may be more resilient in the face of stressors relative to other Indigenous adults. Participants were recruited using posters and ads placed in e-newsletters on campus. To increase generalizability snowball sampling techniques were avoided. No advertising took place in psychological or health treatment centres. Participant recruitment and data collection began in September 2015, and continued over four academic terms, ending in April 2017. The final sample size was 150 adults.

1.1. Child discrimination, AL and cultural continuity We also sought to examine whether associations between discrimination and AL were moderated by cultural continuity (CC), which encompasses identity, cultural engagement, and social connectedness, and has been defined as something that is potentially enduring or linked through processes of historical transformation with an identifiable part of previous traditions (Auger, 2016; Greenwood et al., 2018; Kirmayer, 1994). While cultural engagement may vary at an individual level over the life course due to colonial practices, as a group Indigenous people in most colonized nations have continued to practice their culture continuously. Thus, CC may be viewed as both a population-based and individual-level concept. In the territory in which this study took place CC remains strong. As described by Elder Pete Standing Alone (p. vii): “The federal government and the churches did not succeed in totally destroying our spirituality and our identity, sources of our ways of 2

Social Science & Medicine 241 (2019) 112564

C.L. Currie, et al.

returned the samples to the university in an insulated kit with a freezer pack that had been given to them. These samples were immediately transferred to a −80C freezer. Participants were given a honorarium in two installments: $50 for the in-office visit, and $50 for returning athome measures.

2.2. Procedures Study procedures were approved by the Health Research Ethics Board at the University of Lethbridge. Written consent was obtained from all participants. Working with the IAC, it was determined that salivary rather than blood samples would be used given blood is a sacred element in many Indigenous cultures, a belief that ties in with Indigenous holistic beliefs about the body, self, culture and nature. As saliva is also a substance that comes from the body, a system was put in place in consultation with Indigenous Elders to ensure the wishes of participants were honored. The consent form provided participants the option of having their saliva samples returned to them or included in an Indigenous ceremony led by an Elder that returned the samples to the Earth. Overall, 16% chose to have their saliva returned to the Earth in ceremony, while 2% requested their saliva be returned to them. After screening for eligibility by email or phone (i.e., that participants identified as Indigenous, were post-secondary students, and 18 years or older) participants attended an on-campus study office to complete consent procedures, a survey, and physical assessments (mean completion time = 90 min). Saliva samples were collected at three time points using the passive drool technique. Participants rinsed their mouth with water upon arrival and the first sample was collected after a portion of the survey was completed. Remaining samples were taken 30 and 60 min later. Whole saliva samples were collected in a 2 ml microcentrifuge tube using a Saliva Collection Aid (Salimetrics, State College, PA). During data collection, salivary samples were stored in an in-office freezer and then transferred immediately to a −80 °C freezer. Anthropometrics (height, weight, waist circumference) were taken after the survey, saliva, and blood pressure measures were completed. At home, participants collected a saliva sample at three time points on two consecutive days in which they had typical wake and sleep times: immediately upon waking, 30 min after waking, and before bed. Typically, at home measures were taken very close in time to the inoffice measures, usually over the next two days. At-home samples were collected using the SalivaBio Oral Swab (Salimetrics, State College, PA), a synthetic swab validated for use with salivary cortisol. Participants were instructed to place the swab under the tongue for three minutes and then place the swab in a pre-labeled tube and put it in their freezer. They recorded salivary collection times on forms provided to them. Participants were instructed not to brush their teeth, consume liquids or food, or smoke before collecting the samples. We used strategies recommended to increase adherence including clearly explaining the importance of strict adherence to sampling times, emphasizing the importance of collecting S1 immediately upon awakening, encouraging questions by text/phone/email, providing take-home instructions, advising that kits be placed by the bed for morning collection, and text messaging the evening before sampling to highlight instructions (Stalder et al., 2016). When all six samples were collected, participants

2.3. Measures 2.3.1. Allostatic load AL is a latent variable that captures dysregulation across multiple biological domains. A 2017 systematic review called for a more critical approach to AL measurement to ensure biomarkers captured the biological effects of psychosocial stress rather than physiologic dysfunction more generally (Johnson et al., 2017). Taking this into consideration, we operationalized AL using markers from the three biological domains that framed the original AL index, with a measure of inflammation added (Juster et al., 2010). Thus, AL score in this study was based on a composite of seven biomarkers across four biological domains including: Cardiovascular. Resting systolic and diastolic blood pressure were measured using a Life Source automated sphygmomanometer (Auto Control Medical, Mississauga, ON). Participants were seated and resting quietly for three readings taken approximately 15 min apart. The first reading was discarded. The second and third readings were averaged and used in the AL score. Neuroendocrine. Markers included DHEA-S and CAR. DHEA-S was collected through in-office salivary sampling and analyzed using Enzyme-Linked Immunosorbent Assays (Salimetrics, State College, PA). As per manufacturer's suggestion for DHEA-S, the three in-office samples were pooled and mixed for analysis. To examine CAR, the waking (S1) and 30 min post waking (S2) samples taken at home on the second day were used, and the percent change in cortisol between S1 and S2 was calculated. CAR represents the sharp rise in cortisol levels across the first 30–45 min following morning awakening. In healthy adults, the magnitude of CAR ranges between a 50–156% increase in salivary cortisol levels (Clow et al., 2004). The mean magnitude of CAR was 65.1% in this sample. Metabolic. To calculate BMI, height and weight were measured to the nearest 0.5 cm using a Health O Meter mechanical beam scale and stadiometer. Waist circumference was measured at the top of the iliac crest, to the nearest 0.5 cm. Immune. We measured CRP using the third in-office saliva sample; all samples were analyzed in duplicate using an ELISA (Salimetrics, State College, PA). While cytokines can also be examined for AL, our budget was sufficient to examine CRP alone. AL risk was based on the distribution of the study sample for salivary CRP and DHEA-S by dividing the sample into sex-specific quartiles, with high risk defined by the highest quartile for CRP and the lowest

Table 1 Mean, range and cut-points used for allostatic load (AL) biomarkers (N = 105). Biomarker 1. Cardiovascular Resting SBP (mm Hg) Resting DBP (mm Hg) 2. Neuroendocrine DHEA-S (μg/dL) CAR 3. Metabolic Body mass index (kg/m2) Waist circumference (cm) 4. Immune C-Reactive Protein (pg/ml) Total AL Score

Range

Mean

SD

Cut-point female

Cut-point male

90, 150 59, 111

119.1 78.0

13.0 10.3

> 140 > 90

> 140 > 90

188.5, 16055.6 −98.8, 771.7

4247.0 65.1

3743.0 165.4

< 1419.5 < 50.0 or > 156.0

< 2865.1 < 50.0 or > 156.0

18.8, 48.5 68.9, 166.4

29.0 97.9

6.5 18.1

> 30.0 > 88.0

> 30.0 > 102.0

55.1, 3150.0 0, 6

481.9 2.5

666.9 1.3

> 397.8

> 711.8

Note. SBP = systolic blood pressure; DBP = diastolic blood pressure DHEA-S = dehydroepiandroste. Rone-sulfate; CAR = cortisol awakening response. 3

Social Science & Medicine 241 (2019) 112564

C.L. Currie, et al.

quartile for DHEA-S. As shown in Table 1, we used standard cutoffs for all other biomarkers (Gustafsson et al., 2014; Juster et al., 2013). Consistent with prior studies, one point was assigned if the variable was in the high-risk quartile and 0 if not. Scores were then summed across biomarkers to create a total score.

income: t = −1.50, df = 148, p = 0.14; childhood discrimination score: t = −0.80, df = 148, p = 0.94; CC score: t = −0.04, df = 148, p = 0.97). The gender balance in the included and excluded group was also statistically similar (73% vs. 71%; respectively, χ2 = 0.07, df = 1, p = 0.78).

2.3.2. Childhood racial discrimination The frequency of child racial discrimination was assessed using a single question adapted from the Experiences of Discrimination (EOD) Scale: When you were a child or teenager (up to age 18), how much did you experience unfair treatment because of your Indigenous race or ethnicity? (Krieger et al., 2005). Response items were 1 = rarely or never, 2 = some of the time, and 3 = most of the time. For descriptive purposes, two additional EOD items were included to determine how often participants worried about discrimination directed at themselves and others in their racial group as children. Response options matched those of the first question. To garner information about the nature of discrimination experienced in childhood, an open-ended qualitative question asked participants: Is there anything you would like to share about racial discrimination experienced while you were a child?

2.5. Analysis strategy The frequency and nature of childhood racial discrimination were examined using summary measures and a qualitative thematic analysis. Childhood racial discrimination, coded 1 (rarely/never), 2 (some of the time), and 3 (most of the time) was examined as an ordinal measure given a natural order could be discerned between the responses, but the magnitude of difference between the groups could not be determined. Findings related to this variable were described using frequencies. Within later regression models, this variable was added as an ordinal measure. Narrative inquiry was the primary analytic approach used to characterize the nature of childhood discrimination (Creswell and Poth, 2017). This began with inductive codes assigned to segments of the data, followed by the connection of codes to larger identifying themes. This was proceeded by the connection and clustering of themes to understand patterns in the data, and the selection of representative quotes for each theme (Boyatzis, 1998; Saldaña, 2015). Bootstrapped linear regression models (k = 5000) examined the association between childhood racial discrimination and the continuous form of AL. Bias-corrected and accelerated bootstrap intervals were used to adjust for skew. A series of confounders were tested using individual regression models before entry into the main model (age, gender, Indigenous group, current income group, childhood income group, marital status, number of children, being a single parent, attendance at residential school). Those associated with AL at p < 0.20 were retained (age, current income). Confounders were tested as potential interaction variables using Loess curves and multiplicative interaction terms before entry into the final model; none were found. This included no statistically significant gender differences for the associations examined. Previous studies have controlled for health-risk behaviour and mental health when examining associations between discrimination and AL. We disagree with such an approach, given racial discrimination has predicted later mental health and health-risk behaviour problems across more than 30 longitudinal studies examining a variety of ethnicities and age groups worldwide (Assari et al., 2019, 2017; Paradies et al., 2015). This large body of longitudinal evidence suggests mental health and health-risk behaviour variables should be examined as part of the causal chain linking racial discrimination to AL (i.e., as mediators), rather than noise that is controlled in statistical models, the analysis of which is beyond the scope of the current paper. A stratified analysis was used to examine whether CC buffered the adverse impact of childhood discrimination on AL. The sample was dichotomized into high and low CC subgroups using the sample mean, and two bootstrapped linear regression models (k = 5000) examined the association between childhood racial discrimination and the continuous form of AL for each subgroup, adjusting for age and income. Variance inflation factors calculated across all variables included in regression models indicated multicollinearity was not a concern (range: 1.01 to 1.09). Data were analyzed using IBM SPSS 25 and NVivo 11.0.

2.3.3. Cultural continuity We selected the 10-item Vancouver Index Enculturation Subscale to examine CC (Ryder et al., 2000). Questions examined cultural identity, engagement and connectedness.. Example questions included: (1) I often participate in my Indigenous cultural traditions, (2) It is important for me to maintain or develop the practices of my Indigenous culture, and (3) I believe in the values of my Indigenous culture. Response options range from 1 (disagree) to 9 (agree) for each question. Using reliability generalization, a meta-analysis found the average internal consistency across 14 studies was α = 0.83 (Huynh et al., 2009). In the present study the internal consistency was also strong (α = 0.85). 2.3.4. Covariates Sociodemographic factors included age, gender, income group, Indigenous group, marital status, number of children, single parenting, number of children being carried for, residential school attendance, and medication use. Income group was assessed by two questions that asked participants which income group they most identified with as a child, and as an adult. Response options for each question were: upper income, upper-middle income, middle income, lower-middle income, and lower income. Income group was assessed in this manner to improve validity, given university students may not know their household income as a child, or currently as an adult if they are living with their parents; and given previous Indigenous research has documented low missing values when income was measured in this way in our region. (Currie et al., 2013, 2011). 2.4. Missing data Data were collected from 150 participants, 42 of whom were removed from the analysis because they chose to not complete or return at-home samples, their at-home salivary sample was collected more than 45 min after their wake time, their wake time on two consecutive days was two standard deviations higher than the average wake time for the sample (11.41 a.m.), and/or because the overall timing of athome sampling was completed in ways that did not follow procedure; all of which resulted in the inability to calculate valid CAR (Stalder et al., 2016). Two additional participants were removed because they were pregnant, and one for not reporting their age. There were no missing data on questions related to gender, income, CC, or child discrimination. The final sample size included in the analysis was N = 105. Independent-samples t-tests confirmed the mean age, income, discrimination score, and CC score of participants included and excluded from the analysis for missing data were not statistically different (independent samples t-tests for age: t = 0.86, df = 147, p = 0.39;

3. Results Characteristics of the sample are provided in Table 2. The mean age was 27.7 years (SD = 8.6, range 18–57 years). While the mean age of Indigenous university students in Canada has not been accurately assessed, the mean age of Indigenous people in Canada is comparable at 32.1 years (Statistics Canada, 2017). Almost three quarters of participants were female (73.3%) in keeping with the higher enrollment of Indigenous females compared to males in Canadian universities 4

Social Science & Medicine 241 (2019) 112564

C.L. Currie, et al.

(SD = 1.3, range 0–6). In the full sample (N = 105), childhood racial discrimination was significantly associated with increased adult AL in a bootstrapped linear regression model adjusted for age and income group (Table 4). The full model explained 22% of the variance in adult AL score, 11% of which was explained by childhood discrimination. To examine the role of Indigenous CC in buffering the adverse impacts of childhood discrimination on AL, the sample was stratified into low (n = 54) and high (n = 51) CC subgroups using the sample mean for the 10-item Vancouver Index (M = 76, SD = 10.7, range: 36 to 90), and graphed (Fig. 1). Next, models examined associations between childhood discrimination and adult AL within each subgroup adjusting for age and income. As shown in Table 4, among those in the low CC group, childhood discrimination, current age, and income were all significantly associated with AL. The model explained 41% of the variance in AL score among those in the low CC subgroup; 21% of which was explained by childhood discrimination. Among those in the high CC group, the model explained 6% of the variance in AL score, and only age remained a statistically significant correlate of this outcome.

Table 2 Characteristics of the sample. Sociodemographics

Total N (%)

Total sample Gender Female Male Age 18–24 years 25–34 years 35–44 years 45 + years Indigenous group First Nations Metis Indigenous Current income group Upper-middle/middle Lower-middle Low income Marital status Living with a romantic partner Not living with a romantic partner Number of children None 1–2 children 3 or more children Did you attend residential school Yes No Did not answer Childhood racism Rarely or never Some of time Most of time Allostatic load score 0 to 1 2 to 3 4 to 6

105 (100) 77 (73.3) 28 (26.7) 45 (42.9) 37 (35.2) 16 (15.2) 7 (6.7) 64 (61.0) 16 (15.2) 25 (23.8) 33 (20.0) 51 (48.6) 21 (31.5) 41 (39.0) 64 (61.0)

4. Discussion

60 (57.1) 24 (22.9) 21 (20.0)

Emerging evidence suggests altered AL may be a key aetiologic pathway linking discrimination to health. This study extends current knowledge by highlighting childhood racial discrimination as a determinant of AL among Indigenous adults. The aggregate measure of physiologic dysregulation used in this study suggests Indigenous adults who experienced more frequent discrimination in childhood were experiencing early and more pronounced wear and tear on neuroendocrine, cardiovascular, metabolic and immune system functioning in young and middle adulthood than their peers, after adjustment for age and income. This finding builds on Brody et al. (2014) who found racial discrimination experienced between 16 and 18 years was associated with AL at age 20; and Ong et al. (2017) who found racial discrimination experienced over the life course was associated with AL in middle adulthood. These findings are also consistent with a larger body of evidence suggesting that the cumulative impacts of adverse childhood experiences over time can provoke long-term and even permanent conditioning of neuroendocrine responses and other AL biomarkers (Li et al., 2017; McGowan et al., 2009; Scheuer et al., 2018). In this study, participants recalled racially-targeted, emotionally abusive, and sometimes aggressive experiences of childhood discrimination. Participants linked these experiences not only to how it made them feel at the time, but how it continued to affect them today as adults, including a sense of ongoing resentment and low self-worth. Discrimination was experienced directly by participants as children, as well as within a larger intergenerational context they were conscious of. They worried frequently as children about discrimination directed at others in their racial group, and described caregiver-directed discrimination they had witnessed, the impacts of which could also be hypothesized to have implications for the next generation (Chief MoonRiley et al., 2019), and is an area that future studies could pursue.

7 (6.7) 95 (90.5) 3 (2.9) 29 (27.6) 60 (57.1) 16 (15.2) 22 (21.0) 66 (62.8) 17 (16.3)

(Ferrao, 2010). The percentage of the sample who identified as First Nations matched Census estimates for the country as a whole, while the percentage who identified as Métis was lower than Census estimates (Statistics Canada, 2017). 3.1. Racial discrimination in childhood Approximately three in four participants (72.3%) experienced racial discrimination some or most of the time in childhood. As children, most (80.0%) worried some or most of the time about personally experiencing discrimination, and the majority (62.2%) also worried about others in their racial group experiencing discrimination. Approximately half the sample responded to an open-ended question about childhood discrimination (n = 48, 53.3% of sample). The mean frequency of child discrimination reported by those who did and did not answer this question was “some of the time” and did not statistically differ between groups. Themes and representative quotes(Table 3) provide insight regarding the nature of the discrimination experienced, including incidents that were racially-targeted and emotionally abusive. Many provided detailed descriptions suggesting these experiences remained memorable in adulthood, despite the young age in which some of the incidents had taken place. Participants also discussed racial discrimination directed at their family members, suggesting child discrimination had affected them both personally and intergenerationally. Participants also discussed the residual effects of childhood discrimination on their lives as adults today.

4.1. Cultural continuity, childhood discrimination and AL Indigenous CC buffered the impacts of childhood racial discrimination on adult AL in this study. Among Indigenous adults with high CC, childhood discrimination had no impact on physiologic dysregulation in adulthood, as measured through AL. This finding builds on previous research suggesting a strong racial identity buffers the impact of racial discrimination experienced between 17 and 19 years of age on cytokine levels at age 22 (Brody et al., 2015) among African American youth. As well, having a strong racial identity has been shown to buffer the impact of lifetime racial discrimination on mental distress among Indigenous Sami adults (Friborg et al., 2017). That said, an earlier review of effective strategies for coping with discrimination found racial identity development buffered the impacts on wellbeing in

3.2. Child racial discrimination, AL, and cultural continuity The mean AL score for the sample was 2.5 out of a possible 7 5

Social Science & Medicine 241 (2019) 112564

C.L. Currie, et al.

Table 3 Themed responses: Is there anything you would like to share about discrimination experienced while you were a child? (n = 48). Theme and Supporting Quotations Theme 1

Theme 2

Theme 3

Theme 4

Theme 5

Theme 6

Name calling People in high school thought racism toward First Nations was funny. (P 13, age 19) I experienced this nearly every day in school. Teachers would ask me if I didn't do my work because I was an Indian, and Indians are just lazy and can't do anything. (P53, age 25) Caucasian kids would call me names – savage, wagon burner, squaw. (P55, age 46) Segregated at school In elementary the Native children were treated as if they were social deficits. Many, including myself were put into special classes. Many became targets for the Caucasian kids. (P96, age 30) I experienced discrimination from teachers in both elementary and high school. Once in high school I was automatically placed in a modified class due to being Native. (P83, age 26) When I was a teenager we were segregated from non-Natives in the schools. (P132, age 43) Discrimination during leisure activities Playing hockey and hearing racist comments from players and fans. (P75, age 24) Playing volleyball in Nobleford and some of the spectators were calling us “squaws” (P127, age 29) I went to visit my cousins who lived in Lethbridge and we walked to a nearby playground where there were white kids who started screaming at us to get off their land, that we were ugly and dirty Indians, and that our parents were drunks. (P19, age 32) Aggressive experiences Five years old – An older couple called me a dirty Native baby who should go [expletive]. The neighborhood kids threw rocks at us. People yell things like ‘[expletive] minority, [expletive] Natives’, things of that nature. ‘All Natives are just drunks!!!’ – was very hurtful. (P99, age 26) I witnessed my parents and grandmother being attacked by a large group of White people. I was 8 years old at the time. (P135, age 22) It was really unfair and scary to see how aggressive people would be towards me, even at a really young age. (P60, age 18) Impacts of discrimination directed at others I was just worried about how the teachers would treat my fellow First Nations classmates as we were usually used as ‘examples’. (P3, age 48) When I was a child my mother never made our Metis culture to be anything. I think it's because she is much darker than me and it is this physical ‘Native’ feature that she was once bullied over. (P102, age 21) Impacts of childhood discrimination in adulthood You grow up being resentful of the Western world. (P65, age 25) Discriminated from K-12. Very low self-esteem because of it. (P5, age 41) Yes, I was treated unfairly in Calgary. It caused me to have very low self-esteem and feel like I didn't deserve anything better in life. (P74, age 48)

Table 4 Linear regression models for the direct effects of childhood racial discrimination on AL score with and without stratification by Indigenous cultural continuity.

Model 1: Adjusted, no stratification Childhood discrimination Current age Current income group Model 2: Low cultural continuity Childhood discrimination Current age Current income group Model 4: High cultural continuity Childhood discrimination Current age Current income group

N

Adj R2

105

0.22

48

57

β

SE

B (95% CI)

p

0.23 0.32 −0.12

0.18 0.02 0.14

0.47 (0.11, 0.83) 0.05 (0.02, 0.08) −0.19 (−0.47, 0.10)

< 0.01 < 0.01 0.19

0.27 0.36 −0.24

0.24 0.02 0.19

0.54 (0.05, 1.02) 0.06 (0.02, 0.11) −0.37 (−0.76, 0.03)

0.03 < 0.01 0.07

0.17 0.27 0.03

0.30 0.02 0.21

0.38 (−0.22, 0.99) 0.04 (0.00, 0.08) 0.05 (−0.38, 0.48)

0.21 < 0.05 0.81

0.41

0.06

Note. β is the standardized beta weight, B is the unstandardized beta weight.

2010). CC may have buffered the impacts of discrimination on stress by buffering the degree to which individuals became or remained socially dislocated due to discrimination, given those who were cultural continuous would have greater access to social resources in which they can establish and maintain a meaningful interdependence. Low CC amplified the effect of childhood discrimination on AL in adulthood, with the proportion of variance in adult AL explained by childhood discrimination increasing from 11% to 21% when the sample was limited to those with CC scores that fell below the sample mean. A systematic review found interventions to increase Indigenous CC can be effective in enabling the expression of Indigenous cultural identities, and can have positive health and wellbeing effects (MacLean et al., 2017). Such programs will not, however, address high levels of racism directed at Indigenous children in colonized nations. Our results combine with others to suggest that racial discrimination is an adverse childhood experience that has impacts on health in childhood and later in adulthood. Greater efforts are needed to address this problem. Australia has a national anti-racism school program that is based on the understanding that racism is cruel and unjust, that the country has a

only three out of 12 papers across ethnic groups (Brondolo et al., 2009). Yet it is important to note that the construct examined in this study, cultural continuity, goes beyond positive racial identity to include the extent to which Indigenous adults are culturally and socially engaged within their Indigenous cultural group. This is significant, as immersion can open up a social milieu that encourages individuals to see the many strengths that exist within their culture and history, to hold high esteem for themselves and their ethnicity, and to socialize with others who are also culturally continuous and thus view one another in a similarly esteemed light. Those who were more culturally continuous may have been better equipped to recognize that racist experiences in childhood were due to social injustices and inaccurate stereotypes, rather than personal or ethnic deficits, given they have direct experience with the actual (rather than the stereotyped) cultural values, activities, and spiritual traditions of their group. CC may also provide resilience given human beings are not psychologically self-sufficient, but naturally inclined to establish and maintain a profound interdependence with society (Polanyi, 1944). A lack of psychosocial integration, termed social dislocation, is individually painful and socially destructive (Alexander, 6

Social Science & Medicine 241 (2019) 112564

C.L. Currie, et al.

Fig. 1. Childhood racial discrimination and adult allostatic load score, stratified by Indigenous cultural continuity (SE bars).

effect may have been exacerbated in the present study given the distal nature of the experience.

shared responsibility to create a society free of racial discrimination, and that schools play a vital role in preparing youth for responsible citizenship (NSW Department of Education). Unfortunately, there remains a reluctance to discuss ongoing racial discrimination directed at Indigenous children in Canada and strategies to address the problem.

5. Conclusions Racial discrimination is an adverse childhood experience that may have a biological toll on adult health through altered activation of the stress response system, which could, over time, exacerbate health inequities within this population. Indigenous CC served as a resilience factor that buffered the adverse impacts of childhood discrimination on adult AL score. These results combine with others to highlight the need for increased efforts to prevent racial discrimination directed at Indigenous children, and increased programming to bridge the gap that often exists between Indigenous peoples and their cultures due to historical and ongoing colonization.

4.2. Strengths and limitations Study strengths include guidance by an Indigenous Advisory Committee, the use of a validated measure of Indigenous CC, and the use of a cumulative AL approach to examine the impact of childhood discrimination on biological function. This study also addresses a gap in the literature by examining the impact of racial discrimination on AL within an Indigenous population. Limitations include use of a crosssectional design which precludes inferences about causation and temporal sequence, and a relatively small sample of participants collected in a university setting from one location that is not representative of all Indigenous populations in Canada. Analyses excluded approximately 43% of the sample due to missing data; however, a comparative analysis suggests those excluded did not differ on the exposure, outcome, stratification or confounding variables examined. Some biomarkers measured at one time-point have evidence of diurnal patterns or frequent fluctuation (Hucklebridge et al., 2005; Izawa et al., 2013; Whetzel and Klein, 2010). We did not have a metabolic biomarker. The analysis of salivary biomarkers did not adjust for flow rate.. Response bias due to self-report measures is also a concern, particularly for racism. Research suggests racism, given it is often implicit in nature and pervasive in society, may not always be consciously perceived and reported (Krieger et al., 2005). Thus, self-reported discrimination may result in underreporting, revealing only a small portion of the actual effect of racism on the individual (Berger and Sarnyai, 2015). This

Acknowledgements The authors thank members of the Indigenous Advisory Committee who provided input on the development of the larger project from which this study was based, as well as the Indigenous students who shared their experiences and perspectives with us. This study was funded by an operating grant from the Institute of Indigenous Peoples' Health within the Canadian Institutes of Health Research (Funding Reference Number: 131590, PI: Currie, CL). Dr. Currie's time on this project was supported by an Alberta Innovates Translational Health Chair in Aboriginal Health and Well-Being. References Adam, E.K., Heissel, J.A., Zeiders, K.H., Richeson, J.A., Ross, E.C., Ehrlich, K.B., Levy,

7

Social Science & Medicine 241 (2019) 112564

C.L. Currie, et al.

Greenwood, M., De Leeuw, S., Lindsay, N.M., 2018. Determinants of Indigenous Peoples' Health : beyond the Social. Gustafsson, P.E., San Sebastian, M., Janlert, U., Theorell, T., Westerlund, H., Hammarström, A., 2014. Life-course accumulation of neighborhood disadvantage and allostatic load: empirical integration of three social determinants of health frameworks. Am. J. Public Health 104, 904–910. https://doi.org/10.2105/AJPH.2013. 301707. Heim, C., Ehlert, U., Hellhammer, D.H., 2000. The potential role of hypocortisolism in the pathophysiology of stress-related bodily disorders. Psychoneuroendocrinology 25, 1–35. Hucklebridge, F., Hussain, T., Evans, P., Clow, A., 2005. The diurnal patterns of the adrenal steroids cortisol and dehydroepiandrosterone (DHEA) in relation to awakening. Psychoneuroendocrinology 30, 51–57. https://doi.org/10.1016/j.psyneuen. 2004.04.007. Hungry Wolf, B., 1980. The Ways of My Grandmothers. Harper Collins Publishers, New Work, NY. Huynh, Q.-L., Howell, R.T., Benet-Martinez, V., 2009. Reliability of bidimensional acculturation scores: a meta-analysis. J. Cross Cult. Psychol. 40, 256–274. https://doi. org/10.1177/0022022108328919. Izawa, S., Miki, K., Liu, X., Ogawa, N., 2013. The diurnal patterns of salivary interleukin-6 and C-reactive protein in healthy young adults. Brain Behav. Immun. 27, 38–41. https://doi.org/10.1016/j.bbi.2012.07.001. Jackson, J.P., Weidman, N.M., 2004. Race, Racism, and Science : Social Impact and Interaction. ABC-CLIO. Johnson, J., Wood, A.M., Gooding, P., Taylor, P.J., Tarrier, N., 2011. Resilience to suicidality. Buffering Hypothesis 31, 563–591. Johnson, S.C., Cavallaro, F.L., Leon, D.A., 2017. A systematic review of allostatic load in relation to socioeconomic position: poor fidelity and major inconsistencies in biomarkers employed. Soc. Sci. Med. 192, 66–73. https://doi.org/10.1016/j.socscimed. 2017.09.025. Juster, R.-P., McEwen, B.S., Lupien, S.J., 2010. Allostatic load biomarkers of chronic stress and impact on health and cognition. Neurosci. Biobehav. Rev. 35, 2–16. https://doi.org/10.1016/j.neubiorev.2009.10.002. Juster, R.-P., Moskowitz, D.S., Lavoie, J., D'Antono, B., 2013. Sex-specific interaction effects of age, occupational status, and workplace stress on psychiatric symptoms and allostatic load among healthy Montreal workers. Stress 16, 616–629. https://doi.org/ 10.3109/10253890.2013.835395. Kirmayer, L.J., 1994. Suicide among Canadian aboriginal peoples. Transcult. Psychiatr. 31, 3–58. https://doi.org/10.1177/136346159403100101. Krieger, N., Smith, K., Naishadham, D., Hartman, C., Barbeau, E.M., 2005. Experiences of discrimination: validity and reliability of a self-report measure for population health research on racism and health. Soc. Sci. Med. 61, 1576–1596. Li, Z., He, Y., Wang, D., Tang, J., Chen, X., 2017. Association between childhood trauma and accelerated telomere erosion in adulthood: a meta-analytic study. J. Psychiatr. Res. 93, 64–71. https://doi.org/10.1016/J.JPSYCHIRES.2017.06.002. MacLean, S., Ritte, R., Thorpe, A., Ewen, S., Arabena, K., 2017. Health and wellbeing outcomes of programs for Indigenous Australians that include strategies to enable the expression of cultural identities: a systematic review. Aust. J. Prim. Health 23, 309. https://doi.org/10.1071/PY16061. McEwen, B.S., 1998a. Protective and damaging effects of stress mediators. N. Engl. J. Med. 338, 171–179. McEwen, B.S., 1998b. Stress, adaptation, and disease: allostasis and allostatic load. Ann. N. Y. Acad. Sci. 840, 33–44. https://doi.org/10.1111/j.1749-6632.1998.tb09546.x. McGowan, P.O., Sasaki, A., D'Alessio, A.C., Dymov, S., Labonté, B., Szyf, M., Turecki, G., Meaney, M.J., 2009. Epigenetic regulation of the glucocorticoid receptor in human brain associates with childhood abuse. Nat. Neurosci. 12, 342–348. https://doi.org/ 10.1038/nn.2270. McTaggert, R., 1991. Principles for participatory action research. Adult Educ. Q. 41, 168–187. NSW Department of Education, 2018. Racism. No Way: Anti-racism Education and Resources for Australian Schools. n.d. [WWW Document]. http://www. racismnoway.com.au/ (accessed 2.17.19). Ong, A.D., Williams, D.R., Nwizu, U., Gruenewald, T.L., 2017. Everyday unfair treatment and multisystem biological dysregulation in African American adults. Cult. Divers. Ethn. Minor. Psychol. 23, 27–35. https://doi.org/10.1037/cdp0000087. Available from. Oster, R.T., Grier, A., Lightning, R., Mayan, M.J., Toth, E.L., 2014. Cultural continuity, traditional Indigenous language, and diabetes in Alberta First Nations: a mixed methods study. Int. J. Equity Health 13, 92. https://doi.org/10.1186/s12939-0140092-4. Paradies, Y., Ben, J., Denson, N., Elias, A., Priest, N., Pieterse, A., Gupta, A., Kelaher, M., Gee, G., 2015. Racism as a determinant of health: a systematic review and metaanalysis. PLoS One 10, e0138511. https://doi.org/10.1371/journal.pone.0138511. Phelan, J.C., Link, B.G., 2015. Is racism a fundamental cause of inequalities in health? Annu. Rev. Sociol. 41, 311–330. https://doi.org/10.1146/annurev-soc-073014112305. Polanyi, K., 1944. The Great Transformation: the Political and Economic Origins of Our Times. (Beacon, Boston, MA). Priest, N., King, T., Bécares, L., Kavanagh, A.M., 2016. Bullying victimization and racial discrimination among Australian children. Am. J. Public Health 106, 1882–1884. https://doi.org/10.2105/AJPH.2016.303328. Ryder, A., Alden, L., Paulhus, D., 2000. Is acculturation unidimensional or bidimensional? A head-to-head comparison in the prediction of personality, self identity, and adjustment. J. Personal. Soc. Psychol. 79, 49–65. Saldaña, J., 2015. The Coding Manual for Qualitative Researchers, third ed. Sage Publications, New York.

D.J., Kemeny, M., Brodish, A.B., Malanchuk, O., Peck, S.C., Fuller-Rowell, T.E., Eccles, J.S., 2015. Developmental histories of perceived racial discrimination and diurnal cortisol profiles in adulthood: A 20-year prospective study. Psychoneuroendocrinology 62, 279–291. Available from. https://linkinghub. elsevier.com/retrieve/pii/S0306453015008914. Adam, E.K., Quinn, M.E., Tavernier, R., McQuillan, M.T., Dahlke, K.A., Gilbert, K.E., 2017. Diurnal cortisol slopes and mental and physical health outcomes: a systematic review and meta-analysis. Psychoneuroendocrinology 83, 25–41. https://doi.org/10. 1016/j.psyneuen.2017.05.018. Alexander, B., 2010. The Globalization of Addiction: a Study in Poverty of the Spirit. Oxford University Press, Oxford, UK. Assari, S., Moazen-Zadeh, E., Caldwell, C.H., Zimmerman, M.A., 2017. Racial discrimination during adolescence predicts mental health deterioration in adulthood: gender differences among blacks. Front. Public Heal. 5, 104. https://doi.org/10. 3389/fpubh.2017.00104. Assari, S., Mistry, R., Lee, D.B., Caldwell, C.H., Zimmerman, M.A., 2019. Perceived racial discrimination and marijuana use a decade later; gender differences among black youth. Front. Pediatr. 7, 78. https://doi.org/10.3389/fped.2019.00078. Auger, M.D., 2016. Health: a metasynthesis of qualitative research in Canada and the United States. Int. Indig. Policy J. 7. https://doi.org/10.18584/iipj.2016.7.4.3. Bals, M., Turi, A.L., Skre, I., Kvernmo, S., 2010. Internalization symptoms, perceived discrimination, and ethnic identity in indigenous Sami and non-Sami youth in Arctic Norway. Ethn. Health 15, 165–179. https://doi.org/10.1080/13557851003615545. Bastien, B., 2004. Blackfoot Ways of Knowing. University of Calgary Press, Calgary, AB. Beckie, T.M., 2012. A systematic review of allostatic load, health, and health disparities. Biol. Res. Nurs. 14, 311–346. https://doi.org/10.1177/1099800412455688. Berger, M., Sarnyai, Z., 2015. “More than skin deep”: stress neurobiology and mental health consequences of racial discrimination. Stress 18, 1–10. https://doi.org/10. 3109/10253890.2014.989204. Boyatzis, R., 1998. Transforming Qualitative Information: Thematic Analysis and Code Development. Sage Publications, Thousand Oaks, CA. Brody, G.H., Lei, M.-K., Chae, D.H., Yu, T., Kogan, S.M., Beach, S.R.H., 2014. Perceived discrimination among African American adolescents and allostatic load: a longitudinal analysis with buffering effects. Child Dev. 85, 989–1002. https://doi.org/10. 1111/cdev.12213. Brody, G.H., Yu, T., Miller, G.E., Chen, E., 2015. Discrimination, racial identity, and cytokine levels among African-American adolescents. J. Adolesc. Health 56, 496–501. https://doi.org/10.1016/j.jadohealth.2015.01.017. Brondolo, E., Brady Ver Halen, N., Pencille, M., Beatty, D., Contrada, R.J., 2009. Coping with racism: a selective review of the literature and a theoretical and methodological critique. J. Behav. Med. 32, 64–88. https://doi.org/10.1007/s10865-008-9193-0. Castagné, R., Garès, V., Karimi, M., Chadeau-Hyam, M., Vineis, P., Delpierre, C., KellyIrving, M., Consortium, for the L, 2018. Allostatic load and subsequent all-cause mortality: which biological markers drive the relationship? Findings from a UK birth cohort. Eur. J. Epidemiol. 33, 441–458. https://doi.org/10.1007/s10654-0180364-1. Chandler, M.J., Lalonde, C.E., 1998. Cultural continuity as a hedge against suicide in Canada's first nations. Transcult. Psychiatry 35, 193–211. Chief Moon-Riley, K., Copeland, J.L., Metz, G.A.S., Currie, C.L., 2019. The biological impacts of Indigenous residential school attendance on the next generation. SSM Popul. Heal. 7. https://doi.org/10.1016/J.SSMPH.2018.100343. Clow, A., Thorn, L., Evans, P., Hucklebridge, F., 2004. The awakening cortisol response: methodological issues and significance. Stress 7, 29–37. https://doi.org/10.1080/ 10253890410001667205. Creswell, J.W., Poth, C.N., 2017. Qualitative Inquiry & Research Design: Choosing Among Five Approaches, fourth ed. ed. Sage Publications, New York. Cunningham, J., Paradies, Y.C., 2013. Patterns and correlates of self-reported racial discrimination among Australian aboriginal and Torres Strait Islander adults, 200809: analysis of national survey data. Int. J. Equity Health 12, 47. https://doi.org/10. 1186/1475-9276-12-47. Currie, C.L., Wild, T.C., 2012. Adolescent use of prescription drugs to get high in Canada. Can. J. Psychiatr. 57, 745–751. Currie, C.L., Wild, T.C., Schopflocher, D.P., Laing, L., Veugelers, P.J., Parlee, B., McKennitt, D.W., 2011. Enculturation and alcohol use problems among Aboriginal university students. Can. J. Psychiatr. 56, 735–742. Currie, C.L., Wild, T.C., Schopflocher, D.P., Laing, L., Veugelers, P., 2013. Illicit and prescription drug problems among urban Aboriginal adults in Canada: the role of traditional culture in protection and resilience. Soc. Sci. Med. 88, 1–9. https://doi. org/10.1016/j.socscimed.2013.03.032. Currie, C.L., Wild, T.C., Schopflocher, D., Laing, L., 2015. Racial discrimination, posttraumatic stress and prescription drug problems among Aboriginal Canadians. Can. J. Public Health 106, e382–e387. https://doi.org/10.17269/CJPH.106.4979. Danese, A., McEwen, B.S., 2012. Adverse childhood experiences, allostasis, allostatic load, and age-related disease. Physiol. Behav. 106, 29–39. https://doi.org/10.1016/j. physbeh.2011.08.019. Ferrao, V., 2010. Women in Canada: a Gender Based Statistical Report. Statistics Canada. Fletcher, D., Sarkar, M., 2013. Psychological resilience. Eur. Psychol. 18, 12–23. https:// doi.org/10.1027/1016-9040/a000124. Friborg, O., Sørlie, T., Hansen, K.L., 2017. Resilience to discrimination among indigenous Sami and non-Sami populations in Norway: the SAMINOR2 study. J. Cross Cult. Psychol. 48, 1009–1027. https://doi.org/10.1177/0022022117719159. Government of Canada, 2008. Statement of Apology- to Former Students of Indian Residential Schools. R5-142/2013E-PDF - Government of Canada Publications Canada.ca. Ottawa, ON. Government of Canada, 2018. What is Indian status? [WWW Document]. https://www. aadnc-aandc.gc.ca/eng/1100100032463/1100100032464 (accessed 1.14.19).

8

Social Science & Medicine 241 (2019) 112564

C.L. Currie, et al.

https://doi.org/10.1073/pnas.1417325112. Stalder, T., Kirschbaum, C., Kudielka, B.M., Adam, E.K., Pruessner, J.C., Wüst, S., Dockray, S., Smyth, N., Evans, P., Hellhammer, D.H., Miller, R., Wetherell, M.A., Lupien, S.J., Clow, A., 2016. Assessment of the cortisol awakening response: expert consensus guidelines. Psychoneuroendocrinology 63, 414–432. https://doi.org/10. 1016/j.psyneuen.2015.10.010. Statistics Canada, 2017. Aboriginal Peoples in Canada: Key Results from the 2016 Census. Statistics Canada Catalogue No. 11-001-X. (Ottawa, ON). Whetzel, C.A., Klein, L.C., 2010. Measuring DHEA-S in saliva: time of day differences and positive correlations between two different types of collection methods. BMC Res. Notes 3, 204. https://doi.org/10.1186/1756-0500-3-204. Williams, D.R., 1997. Race and health: basic questions, emerging directions. Ann. Epidemiol. 7, 322–333. https://doi.org/10.1016/S1047-2797(97)00051-3. Williams, D.R., Lawrence, J.A., Davis, B.A., 2019. Racism and health: evidence and needed research. Annu. Rev. Public Health 40, 105–125. https://doi.org/10.1146/ annurev-publhealth-040218-043750.

Scheuer, S., Wiggert, N., Brückl, T.M., Awaloff, Y., Uhr, M., Lucae, S., Kloiber, S., Holsboer, F., Ising, M., Wilhelm, F.H., 2018. Childhood abuse and depression in adulthood: the mediating role of allostatic load. Psychoneuroendocrinology 94, 134–142. https://doi.org/10.1016/J.PSYNEUEN.2018.04.020. Shepherd, Carrington, C.J., Li, J., Cooper, M.N., Hopkins, K.D., Farrant, B.M., 2017a. The impact of racial discrimination on the health of Australian Indigenous children aged 5-10 years: analysis of national longitudinal data. Int. J. Equity Health 16. https:// doi.org/10.1186/s12939-017-0612-0. Shepherd, Delgado, R.H., Sherwood, J., Paradies, Y., 2017b. The impact of Indigenous cultural identity and cultural engagement on violent offending. BMC Public Health 18, 50. https://doi.org/10.1186/s12889-017-4603-2. Sinclair, M., 2015. Honouring the Truth, Reconciling for the Future: Summary of the Final Report of the Truth and Reconciliation Commission of Canada. Truth and Reconciliation Commission of Canada, Ottawa. Solís, C.B., Kelly-Irving, M., Fantin, R., Darnaudéry, M., Torrisani, J., Lang, T., Delpierre, C., 2015. Adverse childhood experiences and physiological wear-and-tear in midlife: findings from the 1958 British birth cohort. Proc. Natl. Acad. Sci. 112, E738–E746.

9