In addition, the high class had a higher body mass index; a lower performance status; a higher number of comorbidities; a higher comorbidity burden; were more likely to self-report a diagnosis of depression or back pain; were more likely to have had surgery, chemotherapy, and radiation therapy; and were more likely to receive an antiemetic regimen that included a neurokinin-1 receptor antagonist and two other antiemetics. This evidence concerns the gene TACR1 and depressive disorder.