The primary objective of this proposed study will be to compare the baseline PET scan to the endpoint scan in 15 BPD patients who have been treated with olanzapine. The comparison of the scans will be done through a statistical image analysis, using a pixel-by-pixel group mean subtraction strategy with appropriate correction for multiple comparisons. In an exploratory fashion we will compare frontal and temporal regions of interest to address hypotheses of which areas of the brain might show changes with olanzapine treatment.