IL4 and major depressive disorder: In a cross-sectional study (17) comparing alexithymics vs. non-alexythymics in a sample of healthy young women, we observed that the alexithymic subjects exhibited significantly decreased production of interleukin1β (IL-1β), IL-2, and IL-4 by phytohaemagglutinin stimulated peripheral blood lymphocytes, associated with reduced ratios of Th1/Th2 (IL-2/IL-10) and of CD4/CD8, as well as reduced CD4 percentages, regardless of anxiety or depression levels.