Racism, racial discrimination, and trauma: a systematic review of the social science literature

ABSTRACT

Objective: The aim of this paper is to provide a systematic review of studies that examine relationships between racial discrimination and trauma in order to further understand the relationship between racial oppression and psychological functioning.

Design: In this review, we describe the characteristics of 28 studies, identified by a comprehensive search strategy, including measurements of racial discrimination and trauma, as well as the nature of the reported associations.

Results: Half of studies included in this review were published in the last 6 years. The majority of studies used cross-sectional designs and were conducted in the United States with adults ≥18 years old. African American, White, Latinx, and Asian populations were most frequently included in these studies. Of the 44 associations examined in these studies, 70% of the trauma symptomology outcomes were statistically significantly associated with racial discrimination. Significant positive associations ranged in strength, with the strongest relationships between racial discrimination and trauma occurring in studies examining veteran populations and moderate relationships among these variables in non-veteran, student populations.

Conclusions: Our findings reveal that current research on race-based trauma seems to be limited by a lack of measures that capture the stress/intensity associated with race-related events, an inability to account for vicarious/collective/intergenerational experiences of trauma, and failure to control for non-race-based trauma.

KEYWORDS:

• Racism
• racial discrimination
• trauma
• race-based traumatic stress
• systematic review

Race refers to the social construct and practice of categorizing humans based on their skin tone, physical features (e.g. eye and/or nose shape, hair texture, etc.), and/or language (Carter and Pieterse 2005). This grouping practice, particularly prevalent in North America, includes the grouping of all people: Whites, people of Color (Blacks, Asians, Latinx, Native Americans), refugees, immigrants, and biracial people. The terms race, culture, and ethnicity are often confused or used interchangeably. Within the United States (U.S.), racial groups have been socially and legally separated for centuries. As such, racial groups have retained distinct cultural patterns which make race and culture, in many cases, seem to be one in the same (Marger 2014). Culture, however, is distinct from race: While race refers to the social practice of categorizing people based on physical features and/or language (Carter and Pieterse 2005), culture is the system of values, norms, behaviors, language, and history passed on from one generation to the next through socialization (Carter 2007). Ethnicity, although also conflated with these concepts, differs still – it is a person’s perceived group membership based on nationality and/or ancestry (Murry, Smith, and Hill 2001). The constructs of race, ethnicity, and culture and their intersections have been the basis of vastly different historical experiences of oppression in the U.S. Historically disenfranchised racial-cultural groups in the U.S. include Black/African, Latinx, Asian/Pacific Islanders, and Native–Indigenous (Carter 2007). More recent groups to experience discrimination and oppression include individuals from Middle Eastern backgrounds (Jamal, Naber, and Naber 2008). For the purposes of this paper, the term, people of Color, will be used to refer to historically disenfranchised American racial-cultural groups.

In the United States, people fall into a racial social hierarchy with Whites at the top as the dominant group, and people of Color at the bottom (Marger 2014; Smedley and Smedley 2005). Feagin (2006, 2014) describes an enduring system of oppression in the U.S. where people of Color have been the targets of a wide range of racism, including social and economic oppression (e.g. slavery, Jim Crow laws, Japanese internment camps, police brutality, mass incarceration, etc.), the negative depictions of people of Color in television, film and other media controlled mostly by Whites (Cortese 2010; Morris 2007; Stanfield 1993; Vera and Gordon 2003) and the everyday acts of invalidation and dismissal people of Color experience in a White-dominant society (i.e. racial microaggressions; Pierce 1995; Solorzano, Ceja, and Yosso 2000).

The behavioral manifestation of racism, racial discrimination, is at the intersection of power and prejudice. Racial discrimination is understood to be a combination of the ideology of racial superiority (racism) and the social structures and interpersonal behaviors associated with dominance and oppression (Pieterse and Powell 2016). As such, racial discrimination manifests in people of Color being denied access to resources, opportunities and the power to define reality (Neville and Pieterse 2009), the normalization of which is known as structural racism (Lawrence and Keleher 1995). Individuals, institutions, and the dominant culture express racism and racial discrimination in different ways, with racism occurring at the interpersonal, institutional, and cultural levels (cf. Jones and Carter 1996). Carter, Johnson, Muchow et al. (2016) categorize racial discrimination (occurring at the individual, institutional, or cultural level) into three types: avoidance wherein people are rejected or ignored because of their race; hostility wherein verbal and non-verbal acts are directed at people to demean, intimidate, or communicate inferior status to them based on their race; and aversive-hostility, wherein one encounters barriers in the form of lack of opportunity or a hostile environment.

A wealth of research indicates that racial discrimination is a stressor for its targets (e.g. Brondolo et al. 2009; Carter 2007; Clark et al. 1999; Pieterse and Carter 2007; Williams and Mohammed 2009, 2013). There is mounting evidence pointing to the connection between racial discrimination and a variety of negative physical and mental health outcomes (e.g. Britt-Spells et al. 2018; Lee and Ahn 2011, 2012, 2013; Paradies et al. 2015; Pascoe and Smart Richman 2009; Pieterse et al. 2012; Schmitt et al. 2014; Smedley 2012; Triana, Jayasinger, and Pieper 2015). This body of work rests on the conceptualization of stress as a phenomenon in which an individual perceives their resources to be insufficient to meet the demand of their environment, creating a stress reaction due to an inability to cope (Lazarus and Folkman 1984). Harrell (2000) has applied this concept to the effects of racism defining racism-related stress as race-related interactions between individuals/ groups and the environment that are “perceived to tax or exceed existing individual and collective resources or threaten well-being” (p. 44). Race-related stress, however, differs still from trauma.

Trauma is related to stress in that psychologists understand it to be a more acute form of stress resulting from a particular event or series of events that overwhelm a person’s typical coping mechanisms (Pearlman and Saakvitne 1995; Van der Kolk 1998). In fact, the etymology of the word trauma, comes from the Greek word, τραῦμα, which is literally translated to “wound” (“Wound” 1989). Thus, the connection between stress and trauma is that some stressful life events have the ability to result in psychological wounds or injuries to the self (Carter 2007). Due to individual differences and the subjective nature of such experiences, two people experiencing the same event or condition may react differently, wherein one may experience stress (with the ability to cope), and the other may experience trauma (overwhelmed by the experience and unable to cope; cf. Carter et al. 2017).

Distressing psychological responses to traumatic experiences have been conceptualized in the field of psychiatry and psychology as a specific disorder – Post-Traumatic Stress Disorder (PTSD; American Psychiatric Association 2013). The hallmark of PTSD has been exposure to a traumatic event (e.g. violent or accidental death/threatened death, actual/threatened serious injury, or actual/threatened sexual violence) with accompanying reactions including feelings of helplessness and fear. It should be noted, however, that the definition and criteria of PTSD has come under criticism for its lack of attention to stressful events associated with racial discrimination and the experience of racism (Butts 2002; Carter 2007). As such, the relationship between racism-related stress and psychological symptoms has become an increasing area of inquiry. Research has been driven by various scholars’ argument that our current conceptualization of trauma needs to be expanded to account for non-life-threatening experiences that do represent a psychological threat and result in emotional pain (Carlson 1997; Helms, Nicolas, and Green 2010).

The race-trauma connection

In research that has examined the prevalence of trauma (in accordance with the PTSD model), researchers have found higher rates of traumatic stress in response to significant life stressors among people of Color as compared to the general population (Breslau et al. 1998). For example, Pieterse et al. (2010) found that racial discrimination was a stronger predictor of trauma-related symptoms than general life stress in a sample of Black college students. Similarly, for Asian students, campus racial climate contributed to a significant amount of variance in trauma symptoms, again more so than general life stress (Pieterse et al. 2010). In a sample of veterans, Loo, Fairbank, and Chemtob (2005), found that the experience of race-related stressors was associated with more severe PTSD outcomes when compared with veterans with no or few race-related stressors. Echoing these findings, Roberts et al. (2011) found Blacks to have significantly higher rates of PTSD (8.7%) than Whites (7.4%), even after controlling for the number of reported traumatic events over the lifespan.

There is also evidence of differential exposure to stressful life events with Whites tending to report less stress associated with life events than people of Color (Norris 1992; Pole et al. 2005). While findings in this area are too few to draw conclusions, the disparity in impact of stressful life events between people of Color and Whites remains unexplained by covariates that theoretically might serve as buffers such as level of acculturation (Marshall and Orlando 2002), socioeconomic status, education, and mental health (Roberts et al. 2011), and frequency of stressful life events (Pole, Gone, and Kukarni 2008).

An important development in the field of race and trauma has been Carter’s (2007) theory of race-based traumatic stress which posits race-based traumatic stress is a unique type of trauma. Carter’s (2007) work builds on Carlson’s (1997) theory of traumatic stress, a form of stress arising out of emotional pain, rather than a violent or life-threatening event, making a connection between racial discrimination and traumatic stress. Carter and Forsyth (2010) found that people of Color who experienced racism were also reported higher levels of anxiety, guilt/shame, avoidance/numbing, and hypervigilance, suggesting that race-based traumatic stress may share some symptoms with the experience of PTSD. Additionally, researchers have documented that interpersonal trauma (i.e. person-to-person trauma) tends to produce more severe emotional reactions than experiences of impersonal trauma (i.e. natural disasters, automobile accidents, etc.; Courtois 2004), which is particularly important given the prevalence of interpersonal race-based stressors.

Given the body of work highlighting the connection between exposure to racism and increased levels of stress in people of Color (e.g. Williams and Mohammed 2009, 2013), higher rates of trauma reactions in people of Color (e.g. Frueh et al. 2002; Frueh, Brady, and de Arellano 1998; Norris et al. 2002; Perilla, Norris, and Lavizzo 2002; Ruef, Litz, and Schlenger 2000), and the adverse physical and mental health effects associated with the experience of racial discrimination (e.g. Britt-Spells et al. 2018; Lee and Ahn 2013; Paradies et al. 2015; Pascoe and Smart Richman 2009; Pieterse et al. 2012; Schmitt et al. 2014; Smedley 2012; Triana, Jayasinger, and Pieper 2015), it seems that an important and necessary next step is to examine the existing literature on racial discrimination as a potential factor contributing to trauma (Bryant-Davis and Ocampo 2005; Carter 2007; Harrell 2000).

Current review

The current review examined the existing literature on the relationship between racism and trauma. The primary focus was to examine associations between racial discrimination and trauma symptoms, with a secondary focus of assessing current approaches to measuring and assessing race-based trauma in the extant literature. Based on our search of the literature, no systematic reviews of the racial discrimination and trauma link were found, therefore the current work marks the first systematic review of empirical studies examining racial discrimination and trauma in adult populations in the United States. This review aims to describe: (1) the nature of associations found between racial discrimination and trauma for adults in the United States; (2) measurement of reported racial discrimination used in this research, including timeframes, settings, and impact of exposure; and (3) other characteristics of this body of research racial discrimination and trauma. In line with theory, we anticipated that moderate relationships would emerge between racial discrimination and traditional PTSD trauma symptoms (e.g. dissociation, intrusive thoughts, etc.). We did however anticipate that the effect sizes would be small given the theoretical inability of the PTSD frame to capture the full spectrum of race-based traumatic stress (Carter 2007). Due to the heterogeneity observed in measurement approaches to both racism discrimination and trauma, we concluded that a meta-analytic investigation was not appropriate at this stage. As such, we report our findings as a systematic narrative review of the racial discrimination and trauma literature as it currently stands.

Method

Literature search and study selection

A systematic narrative review was conducted to review the existing empirical outlining the relationship between racial discrimination and trauma. Using systematic and explicit methods, this study sought to identify, select, and assess relevant primary research on the relationship between racial discrimination and trauma (Wright et al. 2007). The systemic review strategy was guided by Moher et al.’s (2015) PRISMA-P checklist which includes suggested data collection items for a systematic review protocol. As per Moher et al. (2015), we recorded administrative data for each article (title, registration, authors, amendments, support); introduction data (rationale, objectives), and defined our methodology (defined eligibility criteria, search strategy, information sources, data items, outcomes, data collection process, and plans for data synthesis).

Eligibility criteria

The literature search was conducted to identify studies that met the following inclusion criteria:

1. Empirical studies using quantitative methods including (i.e. experimental, retrospective / prospective cohort, longitudinal, and cross-sectional designs).

2. Published in peer-reviewed journals or unpublished dissertations/ theses, manuscripts from the earliest time available to December 2017 were considered.

3. Studies included both a specific measure of racial discrimination (i.e. self-report measure of discrimination based on racial-ethnic backgrounds) and trauma (e.g. PTSD symptomology, trauma symptom checklist, or other self-report measure of experience with trauma) and/or a combined racial discrimination-trauma measure.

4. Participants were adults (ages ≥18; studies that utilized college student populations and included some participants under age 18 were not excluded) and studies were conducted in the United States (immigrants, refugees, foreign-born participants were included as long as the study was conducted in the U.S.). This search was limited to adults in the U.S. given the unique history and system of racism in the U.S. (cf. Feagin 2006, 2014).

Information sources & search strategy

In terms of methodology, the search began with an extensive review of the literature using various combinations of the following search terms: race based trauma, race based stress, racial stress, racial trauma, racial discrimination, racism, perceived racism/discrimination, racial oppression, ethnic discrimination. We explored several databases, including PsychINFO, PsychARTICLES, Medline, EbscoHost, CINAHL, Google Scholar, PubMed, and ProQuest (for dissertation/theses). Reference lists of articles selected for inclusion were mined by hand for additional relevant studies. In addition, Google searches with the same search terms were conducted to search for unpublished articles in PDF form not included in database searches, and experts in the field were contacted requesting unpublished manuscripts and/or manuscripts under review that might meet criteria. A Google Scholar alert with the same key words was also set up to e-mail the primary investigator of any newly added publications during the period of the search (from September-December 2017). All searches were conducted in English. The initial search yielded 94 titles: 64 journal articles, 14 dissertations, 9 book chapters, and 7 unpublished manuscripts that were screened for inclusion.

A detailed screening was conducted to ensure that the studies met the study criteria which reduced the total number of articles and papers (elimination of 69 studies) to 28 studies (5 dissertations, 18 articles, and 5 unpublished manuscripts) that met all of the inclusion criteria and was comprised in the final data set. All study details were recorded in an Excel document.

Data & outcome Items

Variables for which data was sought included any measures and/or items related to racial and/or ethnic-based discrimination (e.g. measures of discrimination frequency and/or stress) and any measures and/or items related to trauma (e.g. PTSD diagnostic measures, items measuring single trauma symptoms such as dissociation and/or flashbacks).

Data collection & coding process

Data was collected by hand by a team of four doctoral-level psychology graduate students. Data was then coded by hand, splitting the team of researchers into two teams of two. Inter-rater reliability was calculated following Huberman and Miles (1994), where a reliability rate of 85% or greater is viewed as statistically acceptable. Agreements were defined as any instance in which the coders pulled the same piece of data from a given codable objective (e.g. title, author, variable). Disagreements were defined as instances in which the coders pulled different pieces of data to the same codable objective. The percent of inter-rater reliability was calculated utilizing Huberman and Miles (1994) formula: (Reliability = Agreement/ Agreement + Disagreement). The overall inter-rater reliability rate for this study equaled 87.2%. Once it was determined that the coding teams were reliable (two consecutive passes of coding where the coders met or exceeded the 85% minimum level of reliability), the remaining articles were coded and data was recorded in an electronic spreadsheet.

Data synthesis

There were no plans for data synthesis beyond descriptive data analysis due to the small sample size and heterogeneity of the data. In terms of descriptive findings, we examined descriptive analyses of the full sample of studies included, as well as subgroup analyses of the quality and characteristics of measures of trauma and racial-ethnic discrimination exposure. Lastly, we examined the nature of associations between racial-ethnic discrimination and trauma.

Results

From the 94 titles generated by the search, 28 studies met the inclusion criteria. Of the 28 papers, 18 were published journal articles and reports and 5 were unpublished articles, and 5 were theses/dissertations. The primary reasons for exclusion were: samples being out of age range, samples not being conducted with participants in the U.S., or studies lacking a measure of trauma and/or racism. A number of studies were also excluded because they utilized measures of general discrimination that did not specify discrimination due to racial, ethnic, or cultural background. Findings were screened to ensure that they were not published from the same study and/or utilizing the same sample.

Description of the studies

Table 1 provides details of the key characteristics of included studies. Half of studies included in this review were published in the past six years (50% n = 14). Most of the studies used a cross-sectional study design (93% n = 26), with two studies utilizing longitudinal designs. All of the studies in this review employed convenience (i.e. non-representative) samples, with a majority of studies including samples of >200 participants (75% n = 21). The most common ethnic/ racial groups represented in the studies were Black (70% n = 20), White (57% n = 16), and Asian (50% n = 14), followed by Latinx (46% n = 13), Biracial (30%, n = 8), Middle Eastern (10% n = 3), and Native American (10% n = 2). Combined, the total number of participants included in this review is 11,775.

Table 1. Characteristics of 28 empirical studies of racial discrimination and trauma.

Year of publication	Number of studies	% of total studies
2000–2005	4	14
2006–2010	10	36
2011–2017	14	50
Study Design I
Observational	28	104
Experimental	0	0
Study Design II
Cross Sectional	26	93
Longitudinal	2	7
Sampling Procedure
Convenience	28	104
Population / Representative	0	0
Sample Size
n < 100	2	7
100 n < 200	5	18
200 n <1000	16	57
n > 1000	5	18
Region of Study
United States	28	100
Study Population Characteristics
Age
≥18	26	93
College-age including some participants <18	2	7
Racial-Ethnic Group
Black	20	71
Latinx	13	46
White	16	57
Asian	14	50
Biracial	8	29
Middle Eastern	3	11
Native American	2	7
Other	2	7
Racial Discrimination Measures
Conceptualization of Racial Discrimination
Measure of Frequency	21	75
Measure Race Based Traumatic Stress Symptoms	7	25
Exposure Timeframe
None	7	25
Specified Timeframe	9	32
Lifetime	12	43
Type of Discrimination
Direct	24	86
Vicarious	4	14
Intensity
Measure of Intensity of Experience	2	7
Setting
Specified setting	10	36
Unspecified	18	64
Dataset
National Dataset	3	11
Other	25	89
Trauma Measures
PTSD-model	20	71
Dissociation	4	14
Other	4	14

Measures of racial discrimination exposure

Almost all racial discrimination exposure measures included some form of frequency (see Table 1), with the majority of studies utilizing Likert-scales (e.g. ranging from never to very often or almost all of the time (n = 12) with two studies measuring frequency asking participants to indicate “yes” or “no” to whether they experienced any events due to their race or ethnicity, and one study asking participants to record the number of times they experienced a race-based event. Other studies used a forced-choice scale that measured perception of discrimination rather than frequency, with a Likert-scale ranging from strongly agree to strongly disagree (n = 4) and two studies used a combined frequency-intensity Likert-scale from 0 this event never happened to me to 4 this event happened and I was extremely upset. A handful of studies were unique in that researchers utilized the Race Based Traumatic Stress Symptom Scale (Carter et al. 2013), a combined measure of race and trauma (n = 7).

In terms of timeframe, the majority of studies examined lifetime exposure to racism (n = 14), followed by studies that examined racism exposure in a specified timeframe (e.g. as an international student, in their current workplace, during time the military, after 9/11; n = 7). The remainder of studies utilized the Race Based Traumatic Stress Symptom Scale (n = 7), examining a single memorable event of racial discrimination.

In terms of setting and experience, most studies examined racial discrimination in a specified setting (e.g. school, healthcare, workplace; n = 10), with the remainder of studies leaving setting unspecified (n = 18) in their examination. Almost all of the studies examined direct experiences of racial discrimination (n = 24), with only four studies including measurement of experiences of intergenerational or vicarious racial discrimination. Of the studies that reported reliability for racial discrimination scales (n = 20), reliability ranged from .67-.98 for racial discrimination scales, with the majority of scales (n = 16; 84%) reporting reliability above .86 (see Table 2 for reliability information of racial discrimination measures).

Table 2. Reliability of measures included in the study.

Racial discrimination measures	α
Spencer Discrimination Scale	0.86
Race-Related Events Scale (RES)	0.86
Schedule of Racist Events (SRE)
Work Environment Inventory (WEI)	0.65
Race-Related Stress Scale: Racial Prejudice & Stigmatization subscale	0.97
Race-Related Stress Scale: Bicultural Identification & Conflict subscale	0.93
Race-Related Stress Scale: Racist Environment	0.93
Race-Related Stress Scale: Total Score	0.97
Impact of Race-Related Events (IRE)
Perceived Ethnic Discrimination Questionnaire (PEDQ)	.74–.84
Acculturative Stress Scale for International Students (ASSIS)	0.92
Race-Related Events Scale (RRES)
Perceived Racial/Ethnic Discrimination Stress Scale
Index of Race Related Stress: Cultural Racism subscale	0.91
Index of Race Related Stress: Institutional Racism subscale	0.95
Index of Race Related Stress: Collective Racism subscale	0.93
Index of Race Related Stress: Individual Racism subscale	0.93
Index of Race Related Stress: Total Score	0.98
Racial Vigilance	0.86
Experiences of Discrimination Scale (EOD)	.67–.74
Everyday Racial Discrimination	0.90
The Oppression Questionnaire (OQ)	0.98
The Brief Perceived Racism in the Workplace Scale (BPR)	0.90
Trauma Measures
Childhood Trauma Questionnaire	0.90
Dissociative Experiences Scale (DES)	0.95
Life Stressors Checklist–Revised
Mississippi Scale for Combat-Related Posttraumatic Stress Disorder-Civilian Version (M-PTSD-C)	.64–.87
Mississippi Scale for Combat-Related Posttraumatic Stress Disorder (M-PTSD)	0.61–0.90
Peritraumatic Dissociative Experiences Questionnaire (PDEQ)	0.83
Posttraumatic Stress Disorder Checklist-Civilian Version (PCL-C)	0.93
Posttraumatic Stress Disorder Checklist-Specific (PCL-S-6)	0.89
Posttraumatic Stress Disorder Checklist-Specific (PCL-S)	0.95
PTSD Symptoms Scale – SR	0.87
Trauma Symptom Checklist-40 (TSC-40)	0.73
Stress Response Questionnaire for Disorders of Extreme Stress (SRQ-DES)	0.78
Posttraumatic Symptom Scale–Self-Report (PSS-SR)	0.91
Alcohol Use Disorder and Associated Disability Interview Schedule (AUDADIS-IV)	0.69
World Mental Health Composite International Diagnostic Interview
Trauma and Attachment Belief Scale (TABS) Full Scale	0.93
TABS: Self Safety	0.77
TABS: Other Safety	0.66
TABS: Self-trust	0.77
TABS: Other-Trust	0.83
TABS: Self-Esteem	0.76
TABS: Other-Esteem	0.73
TABS: Self-Intimacy	0.58
TABS: Other Intimacy	0.73
TABS: Self Control	0.70
TABS: Other Control	0.73
The Life Events Checklist (LEC)	0.63
The Dissociative Symptom Scale (DSS)	0.89
Amount of Exposure to Client Trauma Material
Intensity of Exposure to Client Trauma Material

Notes: blanks signify that reliability information was not reported.

Measures of trauma

The bulk of the studies in this review specifically examined PTSD conceptualizations of trauma (n = 13), with other studies examining dissociate experiences associated with trauma (n = 3), and other measures of trauma (n = 5). The remaining studies used the Race-Based Traumatic Stress Symptom Scale (n = 7), a combined measure capturing symptomology specific to race-based-trauma. The most common measures were versions of the Mississippi Scale for Combat-Related Posttraumatic Stress Disorder (M-PTSD; Keane, Caddell, and Taylor 1988) and the Posttraumatic Stress Disorder Checklist (PCL; Weathers et al. 1993). Of the studies that reported reliability for trauma measures (n = 15), reliability ranged from .61-.95, with the majority of scales (n = 14; 54%) reporting reliability above .75 (see Table 2 for reliability information of trauma measures).

Associations between racial discrimination and trauma

In the studies that examined racial discrimination and trauma, we found consistent patterns of associations, with 70% of associations (n = 31) as positively significant (see Table 3). Significant positive associations ranged from r = .10-.68, with 37% of associations above .45 and 17% of the associations above .50.

Table 3. Findings of 18 empirical quantitative studies of reported racial discrimination and various measures of trauma.

Trauma measure	Racial discrimination measure	Positive		Unrelated	Negative		Publication	Sample	N
Posttraumatic Symptom Scale–Self-Report (PSS-SR)	Everyday Racial Discrimination	0.33	*				Bowleg et al. (2014)^a	Black male adults	526
Stress Response Questionnaire for Disorders of Extreme Stress (SRQ-DES)	Index of Race Related Stress: Cultural Racism subscale			0.21			Douglas (2004)	Multiracial university students	330
	Index of Race Related Stress: Institutional Racism subscale			0.25
	Index of Race Related Stress: Collective Racism subscale			0.14
	Index of Race Related Stress: Individual Racism subscale	0.31	*
	Index of Race Related Stress: Total Score			0.16
	Racial Vigilance	0.26	**
PTSD Checklist-Specific (PCL-S)^††	Race-Related Events Scale (RES)	0.35	**				Flores et al. (2010)	Mexican-American youth and adults	110
Amount of Exposure to Client Trauma Material	The Brief Perceived Racism in the Workplace Scale (BPR)			−0.07			Hahn (2010)	Doctoral-level psychology interns	234
Intensity of Exposure to Client Trauma Material	The Brief Perceived Racism in the Workplace Scale (BPR)				−0.14 *
Childhood Trauma Questionnaire	Schedule of Racist Events (SRE)			0.04			Harrington et al. (2006)	Black and White female university students	231
Life Stressors Checklist–Revised		0.55	**
Trauma Symptom Checklist-40 (TSC-40)	Spencer Discrimination Scale	0.10	*				Kang and Burton (2014)	Incarcerated African-American youth	189
PTSD Symptoms Scale – SR	Perceived Racial/Ethnic Discrimination Stress Scale	0.35	**				Khaylis, Waelde, and Bruce (2007)	Multiracial university students	91
Mississippi Scale for Combat-Related Posttraumatic Stress Disorder (M-PTSD)	Impact of Race-Related Events (IRE)	0.61	**				Loo, Fairbank, and Chemtob (2005)	Asian-American Vietnam veterans	300
Mississippi Scale for Combat-Related Posttraumatic Stress Disorder (M-PTSD)	Vietnam Racial Stressor Scale (VRSS): Racial Prejudice and Stigmatization subscale	0.49	**				Loo et al. (2001)	Asisn-American Vietnam veterans	300
	VRSS: Bicultural Identification & Conflict subscale	0.33	**
	VRSS: Racist Environment subscale	0.41	**
	VRSS: Total Score	0.48	**
Posttraumatic Stress Disorder Checklist-Civilian Version (PCL-C)	Perceived Ethnic Discrimination Questionnaire	0.16	*				Pieterse et al. (2010)^a	Multiracial university students	289
Impact of Events Scale (IES)	General Ethnic Discrimination Scale (GEDS)	0.30	*				Polanco-Roman (2017)	Multiracial university students	1541
The Life Events Checklist (LEC)	The Experiences of Discrimination scale (EOD)	0.21	*				Polanco-Roman, Danies, and Anglin (2016)^a	Multiracial university students	743
The Dissociative Symptom Scale (DSS)	The Experiences of Discrimination scale (EOD)	0.18	*
Peritraumatic Dissociative Experiences Questionnaire (PDEQ)	Work Environment Inventory (WEI)	0.48	**				Pole et al. (2005)	Multiracial urban police officers	668
Mississippi Scale for Combat-Related Posttraumatic Stress Disorder-Civilian Version (M-PTSD-C)		0.28	**
World Mental Health Composite International Diagnostic Interview	Perceived Race-Based Discrimination Experiences Scale	0.17	**				Rodriguez-Seijas et al. (2015)	Non-instutionalized Black American adults	5191
Trauma and Attachment Belief Scale (TABS) Full Scale	The Oppression Questionnaire (OQ)	0.30	*				Swift (2010)	Non-vertan, non-traumatized Black American adults	146
TABS: Self Safety		0.46	**
TABS: Other Safety		0.37	**
TABS: Self-Trust				0.13
TABS: Other-Trust		0.31	*
TABS: Self-Esteem				0.01
TABS: Other-Esteem				0.26
TABS: Self-Intimacy				0.12
TABS: Other Intimacy		0.29	*
TABS: Self Control				0.04
TABS: Other Control				0.16
Dissociative Experiences Scale (DES)	Race-Related Events Scale (RES)	0.12	**				Waelde, Pennington, Mahan et al. (2010)	Multiracial university students	408
Posttraumatic Stress Disorder Checklist-Specific (PCL-S)^††		0.22	**
Posttraumatic Stress Disorder Checklist-Specific (PCL-S-6)^†	Acculturative Stress Scale for International Students (ASSIS)	0.46	**				Wei et al. (2012)	Chinese international university students in the U.S.	383
Mississippi Scale for Combat-Related Posttraumatic Stress Disorder-Civilian Version (M-PTSD-C)	Race-Related Stressor Scale (RRSS): Racial Prejudice and Stigmatization subscale	0.67	**				Zamon Williams (2007)	African-American Vietnam veterans	95
	RRSS: Bicultural Identification & Conflict subscale	0.53	**
	RRSS: Racist Environment subscale	0.48	**
	RRSS: Total Score	0.68	**

Notes: K = 28, although only 17 studies provided usable correlations.

†the specific version with six items (PCL-S-6) was used, where specific events were classified as racial discrimination experiences.

‡self-report measure covering the 17 DSM-IV-R symptoms of PTSD.

^aCorrelations unpublished in manuscript, provided by authors through personal communication.

^bThis measure examines trauma history, not symptoms (i.e. a checklist of 30 traumatic events such as natural disaster, car accident, or physical abuse).

The strongest associations were between the PTSD-specific measure, the Mississippi Scale for Combat-Related Posttraumatic Stress Disorder (M-PTSD) with the Race-Related Stress Scale’s (RSS; two correlations) and the Impact of Race-Related Events (IRE; one correlation), both with Asian-American veteran populations (r = .61, .68, .61, respectively). Moderate associations were found between the Schedule of Racist Events (SRE) with the Life Stressors Checklist–Revised (r = .55), the Oppression Questionnaire with the Trauma and Attachment Belief Self Safety subscale (TABS; r = .46), the Acculturative Stress Scale for International Students (ASSIS) with the Post-Traumatic Stress Disorder Checklist (PCL-S-6; r = .46), both conducted with student populations, and one study screening out any participants with a previous PTSD diagnosis or a report of any PTSD-qualifying traumatic experiences. Further moderate correlations were found between the Work Environment Inventory (WEI) with the Peritraumatic Dissociative Experiences Questionnaire (PEDQ; r = .48), among urban police officers, and again between the Mississippi Scale for Combat-Related Posttraumatic Stress Disorder (M-PTSD) with the Race-Related Stress Scale’s (RSS; r = .53, .48) and the Vietnam Racial Stressor Scale (VRSS; r = .49, .48), again with veteran populations of Color.

Discussion

Scholars have discussed racism and trauma at length (e.g. Bryant-Davis and Ocampo 2005; Carter 2007; Clark et al. 1999; Carter and Forsyth 2009; Carter, Forsyth, Mazzula, et al. 2005; Harrell 2000; Comaz-Diaz and Jacobsen 2001; Helms, Nicolas, and Green 2010), yet a clear demonstration of the association between racial discrimination and trauma has yet to be determined through empirical review. The aim of this review was to examine racial discrimination as a potential factor contributing to trauma and to provide the first systematic review of empirical studies on reported racial discrimination and trauma for adult populations in the United States. Our goals were: (1) to describe the nature and characteristics of this body of research racial discrimination and trauma; (2) to present details of measurement of reported racial discrimination being used in the field, including timeframes, settings, and impact of exposure; and (3) to report the associations found between racial discrimination and trauma as a proxy for evaluating the efficacy of PTSD-specific measures in capturing race-specific forms of trauma.

At first glance, we found moderate to strong, positive associations between racial discrimination and trauma, providing support for the idea that racial discrimination and trauma are likely related (Bryant-Davis and Ocampo 2005; Loo et al. 2001). The findings were stronger than we had expected. A comparison between Carter et al.’s (2013) measure of race-based traumatic stress (Carter et al. 2013) and the DSM-V (American Psychological Association 2013) criteria for PTSD reveals that several symptoms of race-based traumatic stress (e.g. hypervigilance, avoidance, intrusive thoughts, depression, physical symptoms; Carter et al. 2013; Carter and Sant-Barket 2015) overlap with symptoms of PTSD. Given that race-based traumatic stress may share some symptoms with the experience of PTSD, the moderate to strong correlations are not wholly surprising.

A closer look at the strongest findings revealed that the largest positive correlations were found in samples entirely composed of veterans who may also have experienced combat-related trauma, in addition to race-based trauma, thus potentially creating artificially high correlations between measures of racial discrimination and PTSD-defined trauma. It is important to note that Loo et al. (2001) and Zamon Williams (2007), two of the studies reporting the strongest correlations, made adaptations to the Race-Related Stressor Scale (for Asian-American veterans) and the Vietnam Racial Stressor Scale (for African-American veterans) in effort separate the associations between race-related stressors and trauma symptoms from those of combat exposure, military rank, psychiatric distress, and PTSD symptoms. In examining race-based trauma, controlling for other types of trauma is highly important and both Loo et al.’s (2001) and Zamon Williams (2007) works have attended to this issue. Other researchers (e.g. Swift 2010) made efforts to control for “other” types of trauma that may have the potential to inflate the strength of associations by excluding participants who report that they have previously experienced a traumatic event or who have been previously diagnosed with PTSD. There is little evidence, however, that other researchers in the field have attempted to control for “other” types of trauma when attempting to examine race-based trauma (i.e. they have not asked participants to identify if they have experienced non race-based traumatic events or if they had previously been diagnosed with PTSD). This finding highlights the importance of control in future research abound race-based trauma.

A closer look at Swift’s (2010) study with a non-veteran population reveals other sources of trauma were indeed well-controlled for and this study reveals moderate to strong correlations between oppression and the Trauma Attachment and Beliefs (TABS) subscales of self-safety and other-safety, highlighting the connection between race-based experiences with safety concerns. The use of the TABS is particularly noteworthy as it is designed to assess cognitive schemas easily impacted by trauma (e.g. safety, trust, esteem, intimacy, and control; Pearlman 2003). The finding of safety being the only cognitive trauma schema related to oppression in the study echoes Carter’s (2007) theory that race-based traumatic stress may be a unique form of stress.

Similarly, several other studies with non-veteran populations (e.g. Flores et al. 2010; Khaylis, Waelde, and Bruce 2007; Wei et al. 2012) found moderate correlations between PTSD symptoms and racial discrimination. Given that overall, correlations between non-veteran populations and trauma were moderate at best, it is possible that PTSD conceptualizations of trauma may not be capturing the full experience of race-based trauma. In line with this finding, future research should also work to examine theoretically unique aspects of race-based trauma that differ from PTSD such as low self-esteem and anger, as identified by Carter (2007). The strength of associations of low self-esteem and anger with racial discrimination should also be tested.

Measures of racial discrimination

In terms of measures of racial discrimination, the majority of measures focused only on the frequency of racial discrimination experiences. It was surprising that only one measure in our review, The Schedule of Racist Events (SRE; Landrine and Klonoff 1996), examined intensity of the experience, utilizing a combined frequency-intensity Likert-scale from 0 this event never happened to me to 4 this event happened and I was extremely upset. Given the breadth of previous research on the stressfulness of racial discrimination, it was surprising that so few studies incorporated measures that examine intensity of stress associated with the experience of racial discrimination. In our view, the more advanced measures of racial discrimination are those that go beyond frequency and account for both frequency and level of stress.

Furthermore, in examining racial trauma, an advancement in racial discrimination measurement is the examination of symptoms related to specific incidents: all of the instruments included in this study apart from the Race-Based Traumatic Stress Symptom Scale (Carter et al. 2013), focused on cumulative experiences of racial discrimination rather than specific race-based events. In line with the diagnostic criteria of PTSD, it makes sense for racial discrimination (and potential trauma related to racial discrimination) to be examined within the context of a specific event. Therefore, in order to gain an accurate measure of race-based trauma, researchers may want to refrain from cumulative measures and engage in event-specific inquiries.

Lastly, few studies examined vicarious or generational experiences of racial discrimination, with the majority of studies focusing only on direct experiences. Researchers have indicated that vicarious trauma may be particularly important for people of Color: Helms, Nicolas, and Green (2010) have noted the plausibility that people of Color “might experience acts against their personhood as stressful or even traumatic” (p. 68). For example, Dassouri and Silva (1998) describe a Latino American client experiencing PTSD-like symptoms after witnessing border patrol beatings of Mexican immigrants on television. Furthermore, given the unique history of racism in the United States (cf. Feagin 2006), and the wide body of work establishing a potential for intergenerational transmission of PTSD (Crenshaw and Hardy 2005; Kellermann 2001) as an “invisible” form of trauma (Franklin, Boyd-Franklin, and Kelly 2006). It is also surprising that racial discrimination measures typically do not examine intergenerational experiences of racism and racial discrimination (i.e. experiences of grandparents, parents, friends passed down to younger generations). Additionally, given the prevalence of and access to smartphones with video recording capabilities and the growing importance of social media, it seems crucial to examine vicarious experiences racial discrimination (i.e. the vicarious experience of trauma via video footage on internet; cf. Bor et al. 2018).

The challenge, of course, is that for people of Color, racist events are experienced multiple times over one’s lifetime (Landrine and Klonoff 1996). Therefore, the most comprehensive conceptualizations of race-based trauma will need to consider the impact of specific racist events, cumulative race-based incidents, and the existence of any inter-generational transmission of trauma, all of which combined could result in a more accurate measure of race-based trauma. That is to say, race-based trauma may be a more complex form traumatic stress (Ford 2008) and therefore, more complex measures may be needed to capture the experience of racial trauma.

Limitations of current literature

While more research is needed to elucidate how race-based traumatic stress differs from other forms of psychological trauma, the findings from this study shed light on the potential unique nature of race-based trauma, pointing to the need to expand the notion of trauma as conceptualized by the DSM-V to include a wider array of experiences that may be considered traumatic. The current criteria and definition of trauma remains problematic in that it limits the ability for people with other types of traumatic experiences (e.g. race-based trauma) to access appropriate diagnosis, medical care, and insurance reimbursement. Our findings also raise questions about if PTSD symptomology is an adequate measure of race-based trauma due to the weak to moderate correlations between racial discrimination and PTSD in non-veteran samples. Furthermore, the current definition of trauma in the DSM-V may be problematic in that it could also contribute to pathologizing misdiagnoses, especially among people of Color (e.g. clients being diagnosed with paranoid personality disorder when they are really experiencing a race-based traumatic stress reaction). Thus, it remains important for researchers and clinicians to keep in mind those traumatic events that fall outside the DSM criteria when treating clients and making differential diagnoses.

A further limitation relates to the current assessment of racism and racial discrimination. As previously outlined, racism within the U.S. is conceptualized as occurring at both individual/interpersonal and institutional/structural levels (Jones 2000). However, as outlined in the current review, most of the assessment of racial discrimination or experience of racism focus primarily in individual level experiences. The impact of structural racism, vicarious racism, or intergenerational aspects of racism is difficult to capture in measures that rely solely on self-report and typically only capture individual experiences of racial discrimination. As such, there exists the possibility the current findings, though compelling, remain an underestimate of the relationship between racism, racial discrimination and trauma-related symptoms (cf. Bryant-Davis, Adams et al. 2017).

Conclusion

The current review as focused on the empirical findings associated with experiences of racism, racial discrimination and trauma symptoms. The review may serve as an introduction to the ways that researchers and health professionals can begin to respond, to and consider the relationship between racial discrimination and trauma. While this review is based only on studies in the U.S., the findings may serve as a foundation for understanding the negative impact of racial discrimination across nations. The U.S. has a unique history and system of racism, yet the experiences of the groups represented in this study might also be reflective of the experience of other marginalized racial groups outside the U.S., given research that has examined the impact of racism from a global perspective (Paradies et al. 2015). The review also serves to highlight the continued need for health care professionals to be attentive social factors that have a direct bearing on health and well-being.

Disclosure statement

No potential conflict of interest was reported by the authors.