INTRODUCTION

Although traditionally, suicide was believed to be a more crucial public health problem for Whites, recent literature suggests a rapid rise in suicide rate among Blacks.[1, 2, 3] According to a recent report, Blacks may experience similar rates of suicide attempts as Whites.[4] As suicide presents at a younger age among Black populations, less time is available for prevention of suicide among Black.[5]

Although we know that suicide rates vary among ethnic groups,[6, 7, 8] very few studies have explored how ethnicity shapes risk and protective factors of suicide among Blacks in the United States.[9, 10] Different culture, life values and socio-historical experiences may result in differences in the rate and pattern of suicide among various ethnic groups.[11] However, understanding of ethnic specific pathways that lead to suicide among Blacks requires further research.

Joe et al. showed that African Americans are five times more likely to attempt suicide than Caribbean Blacks.[10] Another study by Joe et al. also studied the contribution of psychiatric disorders to suicide attempts among Blacks.[9] However, these studies did not compare African Americans and Caribbean Blacks for the role of each psychiatric disorder on suicidality.

From the long list of risk factors of suicide,[12, 13, 14] psychiatric disorders are possibly the strongest one.[15, 16, 17, 18, 19] A systematic review showed that almost 98% of individuals who commit suicide endorse a clinical diagnosis of psychiatric disorder. Based on the literature, although most psychiatric disorders increase the chance of suicide, mood disorders (accounting for 30% of suicides), followed by substance-use related disorders (18% of suicides) possibly contribute more than other mental disorders.[20, 21]

The current study aimed to test if ethnicity moderates the effect of lifetime psychiatric disorders on lifetime suicidal ideation among a nationally representative sample of Black Americans.

METHODS

Data came from the National Survey of American Life (NSAL), which was conducted ad part of the Collaborative Psychiatric Epidemiology Surveys. The NSAL is comprised of national household surveys collected from 3,570 African Americans, 1,621 Caribbean Blacks and 891 non-Hispanic White adults. African Americans samples, being the largest portion of NSAL, were selected from 48 neighboring states and included households that contained at least one Black adult. The Caribbean Blacks sample included 265 samples that were collected from households within the core sample. The remaining samples were collected from households within geographic areas that had a high Caribbean population.[22] Caribbean Blacks were sampled from residential areas that reflect the distribution of the African Americans population and from additional metropolitan areas where Caribbean Blacks composed more than 10% of the population.[23]

RESULTS

As depicted in Table 1, most African Americans and Caribbean Blacks did not meet criteria for the five lifetime psychiatric disorder(s) included in this study. Among African Americans, major depressive disorder, general anxiety disorder, post-traumatic stress disorder, alcohol abuse disorder and unemployment were positively associated with lifetime suicidal ideation, while age was negatively associated with lifetime suicidal ideation. Gender, education level, marital status and country region were not associated with lifetime suicidal ideation [Table 2].

Table 1. Descriptive statistics of study variables among African Americans and Caribbean Blacks (n=5,181)

Table 2. Impact of psychiatric disorders (lifetime) on suicidal ideation (lifetime) among African Americans (n=3,570)

Among Caribbean Blacks, major depressive disorder, drug abuse and never being married were positively associated, and age and general anxiety disorder were negatively associated with lifetime suicidal ideation. Post-traumatic stress disorder, alcohol abuse disorder, gender, education level, employment and country region were not significantly associated with lifetime suicidal ideation [Table 3].

Table 3. Impact of psychiatric disorders (lifetime) on suicidal ideation (lifetime) among Caribbean Blacks (n=1,621)

In the absence of interaction terms, the model with the pooled sample showed that major depressive disorder, general anxiety disorder, post-traumatic stress disorder, alcohol abuse disorder and unemployment were all positively associated with lifetime suicidal ideation. Drug abuse was marginally associated with higher lifetime suicidal ideation. Age was negatively associated with lifetime suicidal ideation, and ethnicity was not significantly associated with lifetime suicidal ideation [Table 4].

Table 4. Impact of psychiatric disorders (lifetime) on suicidal ideation (lifetime) among African Americans and Caribbean Blacks (n=5,181)

The pooled model with interaction terms showed that major depressive disorder, general anxiety disorder, post-traumatic stress disorder, alcohol abuse disorder and unemployment were all positively associated with lifetime suicidal ideation. Drug abuse did not have any main effect on lifetime suicidal ideation. Age was negatively associated with lifetime suicidal ideation and African American ethnicity had a marginally significant and positive main effect on lifetime suicidal ideation. Interaction between Caribbean Black ethnicity and drug abuse was positive and marginally significant, showing that the effect of drug abuse on suicidal ideation is larger among Caribbean Blacks than African American. The interaction between Caribbean Black ethnicity and anxiety disorder was statistically significant, suggesting that the effect of anxiety disorder on suicidal ideation is larger among African Americans than Caribbean Blacks [Table 5].

Table 5. Impact of psychiatric disorders (lifetime) on suicidal ideation (lifetime) among African Americans and Caribbean Blacks (n=5,181)

DISCUSSION

Based on our findings, ethnicity may modify the additive effect of lifetime psychiatric disorders on suicidal ideation among Black adults in the United States. Based on our additive model, anxiety disorder was positively associated with serious suicidal thoughts among African Americans, but not Caribbean Blacks, while drug abuse was associated with suicidal thoughts among Caribbean Blacks, but not African Americans.

A recent study among Blacks in the United States showed that number of psychiatric disorders is a risk factor of lower age at suicidal ideation and this effect might be dose dependent. In that study; however, the number of psychiatric disorders-not the type of the disorder-was shown to be predictive of age of onset of suicidal ideation among Black adults.[25] Similar effects have been reported among other ethnicities.[26, 27, 28]

Based on Joe et al., psychiatric disorders predict suicide attempts among Black ideators. Joe et al., found that Blacks with psychiatric disorders are eight times more likely to attempt suicide than those without psychiatric disorders.[9] Kessler et al. has also showed that among the general population of US adults, number of psychiatric disorders might be the strongest predictor of suicidal attempt.[29] Major depressive disorder is one of the most widely known psychiatric disorders, which can affect the rate of suicide.[19]

Based on the results of current study, suicide prevention programs geared toward Blacks that consider psychiatric disorders may benefit from an ethnic-specific design.[30] Although screening and treatment of psychiatric disorders is a crucial step in suicide prevention among Black adults, screening of anxiety seems to be more important for African Americans while drug use disorder may be of higher importance for Caribbean Blacks. Thus program planners who wish to reduce suicidal behaviors of Black adults through screening and treatment of psychiatric disorders may benefit from tailoring their screening and interventions based on ethnicity.

The current study had several limitations. As the NSAL was a cross-sectional survey, causative associations are not plausible. Moreover, the validity of the single item measure for lifetime suicidal thought is unknown. Suicidal thought measurement is subjected to possible over-or under-reporting in this study. In addition, we do not have evidence regarding similar validity of diagnoses based on Composite International Diagnostic Interview among African Americans and Caribbean Blacks.[24, 31]

Although our study suggested that ethnicity shapes suicidality of Black adult populations due to psychiatric disorders, we did not study why these associations depend on ethnicity. Future research should explore possible buffers among Caribbean Blacks that cancel out the effect of general anxiety disorder as a risk factor of suicidal ideation. Researchers are also invited to study possible mechanisms that may reduce African Americans suicidal thoughts due to drug abuse.

CONCLUSIONS

To conclude, ethnicity may moderate the additive effect of psychiatric disorders on suicidal ideation among Black adults in the United States. Based on our model, the effect of anxiety disorder seems to be larger for African Americans, while the effect of drug abuse may be more pronounced for Caribbean Blacks.