Due to the likelihood that hormones and peptides influence the weight gain associated with Depakote, blood samples will be archived for later analysis, pending availability of funds. Specifically, a portion of the archives will be used to measure gastric inhibitory polypeptide (GIP) and oxyntomodulin. Oxyntomodulin and GIP will not be assayed immediately because commercially available assay kits are not yet available. Oxyntomodulin has been implicated in the control of food intake and satiety in both humans and animals [9], and GIP modulates insulin secretion and might provide new treatments for diabetes [10]. Additionally, levels of PYY3-36, glucagon-like peptide-1 (GLP-1), leptin, and ghrelin will be measured. PYY3-36 and GLP-1 are distal gut hormones that have been found to reduce food intake [9, 11]. PYY3-36 decreases food intake by 30% when infused into humans [11], and obese humans and rodents have attenuated fasting and post-prandial PYY3-36 levels that are likely associated with their obesity [12]. GLP-1 also decreases food intake in rodents and man, and it works synergistically with PYY3-36 [13]. Leptin reduces food intake [14] and increases energy expenditure in humans [15], while ghrelin increases food intake and is likely an important regulator of food intake [16].