Schizophrenia and affective disorder in black and white patients: a methodologic note.

Contrary to many published reports of higher rates of schizophrenia and lower rates of affective disorder among blacks, this analysis of data collected over a ten-year period in a psychiatric clinic that serves a predominantly black population found minimal differences between the two ethnic groups. Methodologic considerations that reduce spurious black-white differences are discussed. The authors urge proper caution in evaluating such reported differences and propose screening measures to identify biased diagnostic procedures.