As PDE4 is the major enzyme hydrolyzing cAMP in cells of the CNS,13, 14, 22, 27 inhibition of PDE4 produces beneficial effects in a variety of CNS disorders, including depression,12, 27 anxiety,22 memory loss,28, 29, 30 and alcoholism.31, 32. The gene discussed is PDE4A; the disease is major depressive disorder.