The use of ob/ob animals has shown the involvement of catecholamines and serotonin (5-HT) in the leptin-deficient syndrome: in mutant animals, dopaminergic agonists reduce food intake and restrain metabolic dysfunctions, while SSRI antidepressant treatment decreases hyperphagia and hyperglycemia [1]. This evidence concerns the gene LEP and Hyperglycemia.