IFNA1 and major depressive disorder: However, we observed no significant increase in depression symptoms (HAM-D) immediately after IFN-α (7.00 ± 1.32 to 7.50 ± 1.42, t(29) = 0.89, p = 0.38), nor any association between acute changes in depression (4 h) and subsequent development of depression symptoms at 4, 8, or 12 weeks.