There has been studies about the clinical diagnoses of Afro-Americans:
"Recent theoretical models suggest that perceived racism acts as a stressor for African Americans and may be associated with a variety of negative psychological consequences, notably paranoia. Paranoia among African Americans is believed to reflect the lower end of the paranoia continuum based on experiences with racism. Thus, it may be beneficial to measure paranoia on a continuum, but few studies have adopted this strategy. This study examined the relationship between perceived racism and paranoia across the continuum in 128 African American college students." (here)
"Epidemiological data on ethnic racial differences in inpatient psychiatric treatment consistently show, regardless of type of hospital, that African Americans are overrepresented among those with diagnoses of schizophrenia and underrepresented among those with diagnoses of affective disorder.1 The prevalence of diagnoses of paranoid schizophrenia is particularly striking among African-American inpatients. Prevalence studies of inpatient samples revealed that paranoid schizophrenia is the most frequent diagnosis given to African Americans.2–4"As far as rappers are concerned I don't know their music or their culture but saying that their behavior has anything to do with mental illness is stereotype not only rappers but those who have mental issues. I believe it's quite odd to claim that a group, any group of people can be considered mentally ill.
"The disproportionately high rates of schizophrenia, particularly paranoid schizophrenia, diagnosed in African Americans, have also been found in prison inmate populations.5 Moreover, Toch et al.5 argued that the high rate of diagnosis of paranoid schizophrenia among black prisoners, coupled with the fact that African Americans had a substantially greater number of infractions regardless of mental health status, may reflect interactions between cultural factors and pathology to predispose them to aggressive behavior. The cultural factor that they identified was distrust of authority, including those represented in the criminal justice system, because of African Americans’ experience historically in this country. These researchers adopted the concept of “cultural paranoia” proposed by Grier and Cobbs,6 and its extension of “confluent paranoia” introduced by Ridley,7 to support their interpretation.
However, research indicates that attributions of violence or aggression to black individuals seeking mental health services often represent biases associated with racial stereotypes, especially those about African-American males." (here)
I rather leave it to the media that diagnoses Britney Spears as this or that, and the whole collection of diagnoses these kind of journalists analyze on those who are at the spotlights.
It's amazing how easy "crazy"; "madness", "insane", "mental ill"... is still used to whatever is out of the ordinary life.
I wish people could be schizophrenic, bipolar, borderline, have cancer, arthritis - whatever - in peace and only talk about it when or if they wanted.