Anxiety disorders are the most common class of mental health disorders in the U.S. (Kessler et al., 2005
). Although much progress has been made in understanding and predicting the clinical course of anxiety disorders, substantial gaps exist in the literature regarding African Americans, Latinos and non-Latino Whites. This is of particular public health significance given that currently African Americans and Latinos each comprise approximately 13% of the population, and by 2030, it is projected that approximately 35% of the U.S. population will be of these backgrounds (20% Latino and 15% African Americans; (U.S. Census Bureau, 2004
). Despite the increasing and substantial number of African American and Latino individuals in the U.S., there are yet no published data on the clinical course of adult anxiety disorders collected using a prospective longitudinal design in these populations.
The Harvard/Brown Anxiety Research Project (HARP) is a prospective, observational, longitudinal study of anxiety disorders that has been following participants for over 22 years. HARP is one of few studies examining the long-term course of anxiety disorders and has produced findings on the chronic and debilitating nature of anxiety disorders. For example, in 12 years of follow-up the probabilities of recovering from social phobia (SP), panic disorder with agoraphobia (PDA), and generalized anxiety disorder (GAD) were very low (.37, .48, .58 respectively) and lower than comorbid major depressive disorder (.73)(Bruce et al., 2005
). Moreover, for those individuals who do recover, many relapse, with cumulative probabilities of relapse ranging from .39 for SP to .58 for PDA. HARP revealed numerous predictors of a worse anxiety disorder course, such as psychiatric comorbidity (Bruce et al., 2005
, Yonkers, Dyck, Warshaw, & Keller, 2000
), lower socio-economic status (Warshaw, Massion, Shea, Allsworth, & Keller, 1997
), single / divorced marital status (Steketee et al., 1999
), poor relationships (Yonkers et al., 2000
), and an earlier age of onset (Warshaw et al., 1997
). Though HARP has significantly contributed to the understanding of the naturalistic course of anxiety, a major limitation of the original HARP cohort is that 97% of the sample is Non-Latino White.
A number of recent epidemiological studies have begun to examine the prevalence of anxiety and other psychiatric disorders in various racial and ethnic groups including African Americans and Latinos (Alegria et al., 2007a
; Breslau et al., 2006
; Grant et al., 2006
; Huang et al., 2006
; Riolo, Nguyen, Greden, & King, 2005
; Smith et al., 2006
; Williams et al., 2007a
; Williams et al., 2007b
). Two of the largest of these studies are the National Latino and Asian American Study (NLAAS; Alegria et al., 2004
) and the National Survey of American Life (NSAL, Jackson et al., 2004
), which were designed to be comparable to the National Comorbidity Study – Replication (NCS-R; Kessler et al. 2004
). Findings from the NCS-R have estimated the lifetime prevalence of anxiety disorders to be approximately 25% in Latinos, 24% in African Americans, and 29% in Non-Latino Whites (Breslau et al., 2006
). African Americans had a significantly lower rate of anxiety disorders than did Non-Latino Whites.
More recently, NLAAS authors reported a lifetime prevalence of all psychiatric disorders in Latinos that ranged from 28% for men to 30% for women (Alegria et al., 2007). Although this study has not yet reported prevalence rates for specific anxiety disorders, NLAAS findings reveal that higher rates of psychiatric disorders were associated with being Puerto Rican, US-born, third-generation Latino, and English-language-proficient. As the NCS-R included only English speaking Latinos, it seems likely that the NLAAS will find lower rates of anxiety disorders than found in Non-Latino Whites from the NCS-R.
Findings from NSAL indicate that, when compared to a Non-Latino White sample from the NCS-R, the prevalence of many anxiety disorders (GAD, PD, and SAD) is lower among African Americans than Non-Latino Whites, though the prevalence of PTSD is significantly greater among African Americans (Himle, Baser, Taylor, Campbell, & Jackson, 2009
). Further, levels of mental illness severity and disability were greater among African Americans than Non-Latino Whites. That is, though African American participants were less likely to suffer from many of the anxiety disorders, those who did have an anxiety disorder were more greatly impaired than their Non-Latino White counterparts. Caribbean Black respondents with anxiety disorders were the most likely to have severe symptoms and functional problems (Himle et al., 2009
In another large epidemiological study, the National Epidemiologic Survey on Alcohol and Related Conditions, lower 12-month prevalence rates of anxiety disorders were observed in both Blacks (10.4%) and Latinos (8.8%) compared to Whites (11.7%) (Huang et al., 2006
). However, a study of 1,803 young adults (age 19–21) living in Florida (Turner & Gil, 2002
) found somewhat different results. There were no differences in overall prevalence of anxiety disorders between African Americans, Cubans, foreign-born non-Cuban Latinos, and Non-Latino Whites. However, this study excluded Caribbean Blacks. Further, non-Cuban Latinos born in the U.S. were found to have a higher lifetime prevalence of anxiety disorders (19.9%) as compared to Non-Latino Whites (14.6%). This underscores the potential importance of examining nationality and birth in or outside the U.S. when examining the nature and course of anxiety disorders in African Americans (e.g., Caribbean Black or not) and Latinos.
While this data is accumulating on the prevalence and cross-sectional severity of anxiety disorder in minority populations, none of the studies in this area include prospective, longitudinal assessments of clinical course. Thus, there are no published data on the prospectively observed clinical course of anxiety and other psychiatric disorders in African American or Latino adult samples.
1.1. Potential Ethno-racial Differences / Minority Mental Health Disparities in DSM-IV Anxiety Disorder Course
Epidemiological data suggest that ethno-racial disparities may be most observable in the persistence, rather than prevalence, of anxiety disorders (Breslau et al., 2005
). In their work, individuals with anxiety disorders were asked to retrospectively recall the year in which their symptoms first began. Breslau and colleagues concluded that anxiety disorders may be more persistent in minority samples than in Non-Latino Whites because their retrospectively recalled duration of illness was longer. However, the validity of this finding is unclear, due to the reliance on a one-time, retrospective recollection. No other data is available on ethno-racial differences in anxiety disorder course, and no research to date has examined the time-varying variables that may moderate course (e.g., do changes in social economic status or degree of acculturation over time relate to changes in course of anxiety disorders?) or on the detailed nature of disorder course (e.g., time to recovery, time to recurrence, length of well intervals).
1.2. Nature and Course of Culture-Bound Syndromes and Culturally-Relevant Expressions of Anxiety
Culturally-specific syndromes related to anxiety have been described (e.g., Guarnaccia, Rubio-Stipec. & Canino, 1989
; Lewis-Fernandez et al., 2002
; Baer et al., 2003
; Bell et al., 1984
; Fukuda, 1993
; Douglass et al., 1994), but little empirical research exists specifying the nature or course of many of these syndromes. The most fully described culture-bound syndrome closely related to anxiety is ataques de nervios (Guarnaccia et al.,1989
; Lewis-Fernandez et al., 2002
). This syndrome is characterized by a sense of being out of control and symptoms including uncontrollable shouting, crying, trembling, and occasionally dissociative experiences, aggression, and/or fainting. In the NLAAS, 5.4 to 10.9% of the Latino sample reported experiencing ataques, with Puerto Ricans having the highest prevalence (Guarnaccia et al., 2010
). Ataques have been repeatedly found to be associated, cross-sectionally, with an increased likelihood of having a DSM mental health disorder, including anxiety disorders. However, data is lacking on the course of ataques over time, on how this syndrome may influence the course of DSM psychiatric disorders longitudinally, and on how this syndrome may be associated with anxiety-relevant traits, such as negative affect and anxiety sensitivity, over time.
Mal de ojo (the evil eye) and susto (fright or soul loss), are also documented in the DSMIV-TR (APA, 2000
). Recent work has better described these syndromes and begun to examine their prevalence (e.g., Baer et al. 2003
; Bayles & Katerndahl, 2009
; Weller, Baer, de Alba Garcia, & Rocha, 2008
). Mal de ojo is thought to be inflicted on an individual, as a result of the nefarious and often envious stare of another person. Symptoms of mal de ojo are often physical (e.g., fever, diarrhea) but may be psychological as well. Susto is thought to occur as a response to a frightening event that “causes the soul to leave the body” (APA, 2000
) and may be particularly relevant to Latino participants with a trauma history. Little research has examined the nature of these syndromes, and we could not identify any research that examined the course of these syndromes over time, or that has examined the role of anxiety-relevant traits (e.g. anxiety sensitivity, negative affect) in the presentation of these syndromes. In one of the few studies examining both of these syndromes (Bayles & Katerndahl, 2009
), a 10-minute survey was administered to 100 Latino primary care patients, who were primarily of Mexican decent. Participants reported high rates of lifetime experience with mal de ojo (10%), susto (14%), and ataques de nervios (6%). Moreover, the occurrence of ataques was significantly correlated with susto.
Though not truly a culture-bound syndrome, sleep paralysis (the temporary loss of voluntary muscle movement upon wakening or falling asleep), is thought to be more frequent in African Americans, and most frequent in individuals with panic disorder, PTSD, and/or history of trauma (Ohayon & Shapiro, 2000
; Paradis, Friedman, & Hatch, 1997
; Sharpless et al., 2010
; Sharpless & Barber, 2011
; Steine et al., 2011
). A recent systematic review (Sharpless & Barber, 2011
) attempted to estimate the pooled prevalence rates for sleep paralysis across 35 studies. The authors estimate that sleep paralysis occurs in approximately 7.6% of the general population, 34.6% of patient samples with panic disorder, and as many as 44.3% of African Americans with psychiatric disorders such as panic disorder. There is no existing data on the longitudinal course of sleep paralysis, or its relationship to anxiety disorders over time.
For all of these culturally-relevant anxiety-related syndromes, data is lacking regarding course and relationship, over time, to other anxiety symptoms and functioning.
1.3. Potential Moderators of Course of Anxiety Disorders of Particular Relevance to Ethno-racial Minorities
1.3.1. Treatment Received / Mental Health Treatment Disparities
Ethno-racial minorities suffer health care disparities in access to and quality of treatment (Atdjian & Vega, 2005
; Schraufnagel, Wagner, Miranda, & Roy-Byrne, 2006
). Recent studies have begun to examine the unmet need for mental health services in African Americans (Jackson et al., 2007
; Neighbors et al. 2007
) and Latinos (Alegria et al., 2007b
; Vega et al., 2007
). Breslau et al. (2005)
suggest that although there are assumptions that ethnic disadvantage in treatment received may be a source of the increased persistence of mood and anxiety disorders, this issue suffers from a lack of empirical data. Further, they report that the ethno-racial differences observed in the persistence of disorders remained after controlling for treatment differences. To date, Breslau et al. (2005)
is the only study that examines if disparities in treatment for mood and anxiety disorders offer a partial explanation for any existing ethno-racial disparities in course of anxiety disorders.
1.3.2. Environmental Stressors
Cultural differences in stressful life conditions may be a risk factor contributing to potential ethno-racial disparities in the course of anxiety and depressive disorders (Breslau et al, 2005
). Stressors that vary between cultural groups range from the relatively common experience of major life stressors to less frequent, but impactful events such as trauma exposure. Some studies suggest that ethno-racial minorities are at higher risk for certain types of trauma exposure, such as assault violence (Breslau et al., 1998
) and for the development of PTSD (Koenen, Stellman, Stellman, & Sommer, 2003
). Observed cross-cultural differences in trauma exposure may be partly accounted for by demographic variables such as lower income, residence in high crime neighborhoods, and less education (Adams & Boscarino, 2005
; Brewin et al., 2000
; Galea et al., 2004
1.3.3. Country of Origin and Duration of U.S. Residence
Factors such as country of origin and time spent in the U.S. may impact the course of anxiety disorders. The NSAL study of mental disorders in the black population of the U.S. suggests that black Caribbean-born female immigrants to the U.S. had a lower 12-month risk of anxiety disorders, substance abuse, and any mental disorder compared to other African Americans. Longer length of residence in the U.S. was associated with increased risk of lifetime mental disorders for all Caribbean immigrants (Williams et al., 2007b
). Similar findings have been reported from the NLAAS (Alegria et al., 2007c
), which showed that U.S. origin and increased duration of residence were associated with greater mental health burden in Latino individuals. Differences due to length of residence were accounted for by family stressors, contextual factors and social status factors.
1.3.4. Social Economic Status
Anxiety disorders may be influenced by access to resources in the environment and thus indicators of social status such as income and education may be relevant moderators of anxiety disorder course. A number of studies have shown that low income is associated with increased prevalence and severity of anxiety disorders (e.g. Kessler, Mickelson, & Williams, 1994; Roy-Byrne, Russon, Cowley, & Katon, 2003
). Further, this relationship may not be solely due to access to at least minimally adequate mental health treatment (Roy-Byrne Joesch, & Wang; 2009
). The association between social economic status (SES) and anxiety is complicated in that whereas lower SES may set a context for the development of more anxiety, it is also true that anxiety disorders may lead to work dysfunction and reduced SES. Interestingly, perceived social status (a perception of one's social status relative to others in the U.S. based on money, education, and job respect) has been suggested to be an even more relevant correlate of risk for anxiety disorders (Alegria et al., 2007c
), than objective indicators such as income and education.
1.3.5. Acculturation and Enculturation Alegria et al. (2007c)
provide a comprehensive description of the complex issues associated with studying adaptation to a new culture. They differentiate the construct of acculturation (acquisition of cultural elements of the dominant society) from the process of enculturation (which focuses on preserving the norms of the native group). The authors argue that both processes can occur simultaneously and should be measured separately as potential contributors to mental health. To date, little research has examined the roles of acculturation and enculturation in mental health functioning, and no studies have investigated the long-term dynamics of these processes in relation to anxiety disorders.
1.3.6. Experienced Discrimination
Experienced (or self-reported) racial or ethnic discrimination is associated with worse self-reported physical and mental health (Borrell et al., 2006
; Gee, Ryan, Laflamme, & Holt, 2006
; Seller, Bonham, Neighbors, & Arnell, 2009
; Finch, Kolody, & Vega, 2000
; Siefer, Finlayson, Williams, Delva, & Ismail, 2007
) in community samples. There are a few studies demonstrating associations between experienced discrimination and anxiety disorders. Kessler and colleagues (1999)
found that self-reported discrimination (based on race/ethnicity, gender, religion, age, or other factors) was associated with major depression and generalized anxiety disorder. Another study which utilized a more comprehensive assessment of DSM-IV mental disorders, (Alegria et al., 2007c
; Gee, Spencer, Chen, Yip, & Takeuchi, 2007
) found that self-reported racial discrimination was associated with a greater probability of having any DSM-IV disorder, depressive disorder, or anxiety disorder within the past 12 months, controlling for socio-demographic characteristics and other variables.
1.3.7. Family Burden and Family Cultural Conflict
Family burden refers to demands from immediate and extended family members. Family cultural conflict refers to conflict with family around issues affected by cultural beliefs, such as career goals. Minorities from families in which different members are at different levels of acculturation and enculturation may experience higher rates of family conflict. Alegria et al. (2007c)
suggest that family burden and family cultural conflict are associated in cross-sectional analyses with an increased risk for 12-month prevalence of anxiety and depressive disorders in Latino individuals.
1.3.8. The Need for Longitudinal Data
Research has begun to examine the relationship between anxiety and a number of individual and societal factors, with particular relevance to ethno-racial minority samples (i.e. treatment received, environmental stressors, country of origin, duration of U.S. residence, SES and perceived social status, acculturation, enculturation, perceived discrimination, family burden, family cultural conflict). However, the lack of prospective studies on the course of anxiety disorders in minority samples has caused a dearth of knowledge regarding how these constructs may affect the long-term course of anxiety. Further, many of these variables are time-varying, rather than static. For example, duration of time in the U.S. increases each year an individual continues reside in this country. Income varies with as individuals find better work or are laid off. Degree of acculturation may increase over time, etc. There is a need for longitudinal studies that may examine how anxiety and functioning change over time, as individuals and their lives change.
1.4 HARP–II Specific Objectives
Given the absence of available data on the clinical course of anxiety disorders in African Americans and Latinos, and the possibility that the socio-cultural factors described above may moderate the course and outcome of anxiety disorders, the aims of HARP-II are:
- AIM 1: Create the first comprehensive description of the prospective clinical course of psychopathology and psychosocial functioning associated with anxiety disorders in African Americans, Latinos, and Non-Latino Whites.
- AIM 2: Test hypothesized predictors (e.g. nativity/immigration status; perceived social status; acculturation and enculturation; experienced discrimination; family burden and family cultural conflict) of the prospective clinical course of psychopathology and psychosocial functioning associated with anxiety disorders within each of the 3 ethnic groups.
- AIM 3: Compare the prospective clinical course and outcome of anxiety disorders among African Americans, Latinos, and Non-Latino Whites.
- AIM 4. Identify which within-group predictor variables vary by ethnicity and are associated with between- group differences in prospective course and outcome of anxiety disorders. That is, we will first examine which demographic, clinical, treatment history, and environmental stressor variables studied as within-group predictors in Aim 2 show significant variation across ethno-racial groups and then incorporate the most salient predictors that emerge to test the hypothesis that socio-cultural variables will be associated with ethno-racial differences in course.