African Americans (AAs) with major depressive disorder (MDD) experience more impairment and poorer treatment outcomes relative to whites, yet are underrepresented in family studies of MDD. In a recent study, one of the first to investigate the familial aggregation of major depression among AAs, the effect of family history (FH) of MDD appears to be exacerbated among individuals exposed to high trauma. Participants' reports of depression from clinical and FH interviews were used to examine depression rates among 435 first‐degree relatives and half‐siblings of 63 depressed cases and 222 relatives of 33 nondepressed controls. Researchers found:

• Cases and controls did not differ in either FH of MDD, or prevalence of MDD in relatives.
• However, exposure to high trauma was associated with increased risk of MDD and the combined effect of FH and trauma was greater than expected under an additive model.
• Similarly, the relative risk for MDD among relatives of cases with high‐trauma levels was 2.2 (1.24–4.2), compared to relatives of controls with low trauma.