■ A decrease of the number of NK and cytotoxic T cells, including CD8+ cells and a shift in Th1 and Th2 cells, with higher expression of the latter, in patients with higher levels of stress, anxiety, depression, negative affect, alexithymia, dysfunctional coping styles and unhealthy health behaviors and a benefic role of positive affect, adjusted coping styles, meaning in life and stress related growth. The gene discussed is CD8A; the disease is major depressive disorder.