A repeated measures GLM ANOVA showed a marked improvement of depression severity over time (F = 69.37, d.f. 3,75, p < 0.0001), with the expected abrupt amelioration at the first TSD then followed by a further improvement, and a significant effect of the IL-1β:IL1ra ratio on the pattern of decrease of HDRS scores (interaction with time: F = 3.00, p = 0.0360). This evidence concerns the gene IL1B and major depressive disorder.