Factors significantly associated with depression among HIV-positive patients on antiretroviral therapy included employment status [AOR = 0.22(95% CI 0.13–0.36)], the patient’s most CD4 count [AOR = 6.99 (95% CI 2.81–17.38)], duration of months on antiretroviral therapy [AOR = 5.05 (95% CI 2.38–10.74)] and presence of chronic non-communicable diseases [AOR = 7.90 (95% CI 4.21–14.85)]. The gene discussed is CD4; the disease is major depressive disorder.