Antidepressant Drugs and Phosphodiesterases

Abstract

This section aims to introduce the antidepressants and phosphodiesterases (PDEs) from four aspects. First, the general principle and background information of antidepressants are introduced, and the relationship between antidepressant and PDE is discussed. It is important to note that recent studies have pointed to the potentially important roles of brain-derived neurotrophic factor (BDNF) in the pathophysiology of depression and the activity of antidepressant drugs. Serum BDNF levels are lower in depressed patients and increased in response to antidepressant treatment. Second, serum BDNF concentrations are positively related to cortical BDNF levels. It is, therefore, quite conceivable that increased serum BDNF levels after a long-term treatment with antidepressants are beneficial to depressed patients. Third, it has been shown that short-term SSRI treatment in depressed patients remediates amygdala hyperactivity in response to negative emotional stimuli prior to clinical improvement in depressed mood. Finally, PDE4, one of the 11 PDE families, is an important component of the cyclic adenosine monophosphate (cAMP) signaling cascade, which has been implicated in both pathophysiology and treatment of major depressive disorder (MDD).