In a large, nationally representative US sample of adults, after we adjusted for sociodemographic characteristics, African Americans and Caribbean Blacks had equal or lower prevalence than non-Hispanic Whites of lifetime and 12-month diagnoses of several Axis I psychiatric disorders. Among Blacks in the study, Caribbean Blacks had lower lifetime prevalence of MDD, alcohol dependence, and drug abuse than did African Americans. Furthermore, Caribbean Blacks had lower likelihood of 12-month diagnoses of social anxiety disorder and substance use disorder but had greater likelihood of psychotic disorder diagnosis than did African Americans. There were no differences in persistence of Axis I disorders between Caribbean Blacks and African Americans although differences existed when each group was compared with Whites. The study, which is the first one to provide national estimates of personality disorder diagnoses in both African American and Caribbean Blacks, found significant differences in risk of several Axis II personality disorders compared with non-Hispanic Whites.
Consistent with previous studies that have shown decreased prevalence of major depressive disorder, anxiety disorders, drug abuse, and alcohol dependence among Blacks in general,15,25,26,43
this study found equal or lower 12-month and lifetime prevalence of these Axis I psychiatric disorders in Caribbean Blacks and African Americans compared with non-Hispanic Whites after we adjusted for socioeconomic characteristics. Despite having many risk factors for psychiatric disorders, protective factors may attenuate these risks among African Americans and Caribbean Blacks. Involvement in family, religious, and other community networks; disclosure of perceived discrimination; and cultural norms about distress tolerance may promote increased resilience.10,44–46
In addition, religious affiliation may discourage alcohol and drug use.22,47
Genetic protective factors for substance use disorders may also play a role. For example, the ADH1B*3 and ALDH1A1*3 alleles of alcohol dehydrogenase are more common among African Americans than non-Hispanic Whites.48
These alleles are associated with decreased family history of alcoholism, decreased hedonic responses to alcohol, and increased metabolism of alcohol to acetaldehyde leading to uncomfortable side effects, which tend to deter alcohol consumption49,50
and lower the risk of alcohol dependence.
We also found that despite overall lower likelihood of any anxiety disorder among African Americans, African Americans had greater persistence of anxiety disorders than did non-Hispanic Whites. Lower treatment rates,51,52
poorer quality of the treatment when it is sought,15,53,54
and higher and more chronic exposure to actual or perceived race-based discrimination55,56
may contribute to this increased chronicity. Lack of opportunities to speak to others about discrimination is associated with increased odds of anxiety disorders in Black respondents.10
Furthermore, culturally normalized anxiety about perceived discrimination may decrease African Americans’ motivation to seek treatment. African Americans also had lower persistence of substance use disorders than did non-Hispanic Whites. Recent increases in access to treatment of substance use disorders among Blacks may contribute to these findings.52,57
The NESARC was the first epidemiological survey to examine the relationship between race and ethnicity and a wide range of personality disorders among African Americans and Caribbean Blacks. African Americans were less likely than non-Hispanic Whites to be diagnosed with avoidant or dependent personality disorder, but more likely to be diagnosed with paranoid personality disorder. Furthermore, both African American and Caribbean Blacks were more likely to be diagnosed with schizoid personality disorder. Several reasons may contribute to these higher rates of Cluster A personality disorders among Blacks.
First, the historical legacy of the United States has led to continued concerns among Blacks about oppression in American society. Our findings may be partially understood as a natural response by a minority group to a society in which racism, discrimination, and economic and social marginalization are not uncommon.10,45
The experience of racial profiling may also lead to cultural mistrust.58,59
The point at which distrust in the face of adverse environmental circumstances becomes pathological may not be easy to delineate.
Second, socializing predominantly with members of one’s same race and actively promoting cultural pride is associated with multiple benefits, such as increased self-esteem, academic achievement, anger control, and decreased anxiety in youths.60
It may also promote coping strategies that might sometimes be understood as Cluster A traits, such as suspicions about members outside one’s culture, mistrust, and limited interaction with members outside one’s cultural group.
Third, the assessment of patterns of behavior is dependent on the cultural norms underlying the assessment instrument. The diagnostic criteria for personality disorders may have some inherent cultural biases. The personality disorder criteria for antisocial and paranoid personality disorders may be more likely to be attributed to Blacks than to others.61
Future studies should explore the relationship between cultural factors and personality disorder diagnostic criteria.
Fourth, genetic influences may also partially contribute to ethnic differences in personality traits. Because personality traits are partially heritable, differences in allele distribution, gene-by-environment interactions, and epigenetic factors, may all contribute to higher prevalence of symptoms of Cluster A disorders among Blacks.62–65
Although more complex, they may be comparable to high-risk alleles associated with prostate cancer in Black men66
or the low-risk alleles associated with alcohol use, discussed previously.
Regardless of the reasons underlying it, the higher prevalence of Cluster A personality-related behaviors among Blacks is likely to interfere with their lives in a culture that does not generally value those traits. Black patients are more likely to be diagnosed with schizophrenia rather than with an affective disorder with psychotic features even when clinicians are blind to race.67,68
Understanding racial/ethnic contributions to Cluster A personality symptoms may aid in clinical assessment and diagnosis of Black patients with psychotic spectrum symptoms. Furthermore, for Blacks, personality disorders are associated with decreased lifetime likelihood of exposure to available psychosocial and medication treatments and fewer treatment sessions after treatment is initiated.69
The findings from this study are overall broadly consistent with the NSAL results with 3 exceptions. The present study found lower odds of lifetime alcohol dependence, drug abuse, and MDD in Caribbean Blacks compared with African Americans, whereas the NSAL did not find significant differences between these groups for these diagnoses.25,70
However, at least 2 previous studies have also found lower alcohol use disorder in Caribbean Blacks compared with African Americans,71,72
providing support for our finding. The difference in the prevalence of the substance use disorders may be also partially related to use of alcohol and substance abuse as screeners for dependence in the World Health Organization Composite International Diagnostic Interview, which was used in the NSAL. This approach can lead to an underestimation of prevalence of substance use disorders that differs by ethnic subgroup73
The reasons for the difference in prevalence of MDD may be more complex. Overall, the lower rates of MDD in Caribbean Blacks than in African Americans are consistent with the overall pattern of lower rates of Axis I psychiatric disorders among Caribbean Blacks documented in this study. Small differences in the sampling strategies or assessment instruments may have also contributed to the differences. Nevertheless, it is possible that the NESARC may have partially underestimated or the NSAL overestimated the prevalence of MDD and certain substance use disorders in Caribbean Blacks.
This study has several limitations. First, as with all cross-sectional epidemiological surveys, this study can establish associations, but not determine causality, between race/ethnicity and psychiatric diagnoses. Second, we relied on DSM-IV
criteria for diagnosis of psychiatric disorders. These categories may not optimally reflect the psychiatric disorders of specific racial and ethnic groups, although a number of studies have explored this issue and found that DSM
criteria are appropriate cross-nationally.74,75
Third, we focused our study on African Americans and Caribbean Blacks. Sample size and associated statistical power considerations precluded us from examining finer-grained subdivisions. Finally, we focused on psychiatric diagnoses and sociodemographic factors and did not explore the role of physical health indicators such as obesity, smoking, and medical diagnoses, which might further our understanding of the interplay between race, medical conditions, and mental health.76
In summary, Blacks have lower prevalence of most Axis I disorders than do non-Hispanic Whites. African Americans have greater persistence of anxiety and lower persistence of substance use disorders than do non-Hispanic Whites. This study contributes important data and analysis of the relationship between race/ethnicity and personality disorder diagnoses among African Americans and Caribbean Blacks in the United States. Understanding psychiatric illness within the population of Blacks in the United States is essential to improve the care of this historically underserved community.