Effects of Modafinil on Olanzapine Weight Gain

This study is designed as a 3 week, randomized, double blind, placebo controlled, trial. Olanzapine and modafinil will be titrated to 10mg and 200mg respectively. Feeding lab assessments will be conducted at baseline and endpoint. Assessments of hunger/satiety, kilocalories consumed and weight will be obtained. Plasma ghrelin and PYY3-36 levels will be drawn at baseline and endpoint prior to breakfast and two hours post. Study hypothesis: The modafinil/olanzapine group will gain less weight than the olanzapine/placebo group over three weeks of drug intake.