The author, after a short historical introduction which shows the Medicine, especially the Neurology, as the predecessor of the Psychiatry, intents to relate in a theorico-practical way the anxiety and the depression within a bio-chemical and endocrinological frame. He presents the hipo and hipercalcemia signals and symptoms demonstrating with a casuistic from his clinical practice the similitude between anxiety and depression respectively. Finally he realizes a theorical analysis about the investigations published over the AMP-ciclic and infers about the hormonal interference and the clinical data linked with the manic-depressive disease.