Thus, the main goal of this study was to investigate sleep quality, daytime sleepiness, depression, and laboratory variabilities (levels of serum phosphorus, leukocytes, and CRP) and interdialytic weight gain in HD patients on a chronic hemodialysis treatment program with respect to the measured levels of alexithymia and to examine which factors most affected the daytime sleepiness of HD patients. The gene discussed is CRP; the disease is major depressive disorder.