 This study is designed as a randomized double blind, parallel group trial to evaluate the effect of modafinil a proposed H1 agonist vs. placebo on eating parameters, weightBMI and sedation in healthy human subjects receiving olanzapine over a three week study period. This project utilizes the current state of the art feeding lab procedures, as reviewed by Mitchell and colleagues Mitchell et al. 1998, to better characterize the effect of modafinil on olanzapine associated eating behavior. This project will help to determine the efficacy of utilizing a H1 agonist as an adjunctive medication in patients receiving atypical antipsychotic therapy to prevent weight gain and excess sedation. 