Statistical analysis revealed that the changes in serum glucose at study completion were significant (p<0.05). The mean serum glucose level was 87.3 mg/dl (SD=6.7) at baseline and 73.7 mg/dl (SD=10.5) at study completion. The patients’ mean weight at 8 weeks was 192 lb, with an average weight gain of 10 lb (SD=7). Their mean olanzapine dose at study completion was 11.8 mg/day (SD=6.7). Three out of seven patients had serum glucose levels below 70 mg/dl at week 8 (i.e., 65, 68, and 57); two out of three continued to use olanzapine and had normal serum glucose levels at the 1-month follow-up. The other patient discontinued olanzapine and had a normal serum glucose level at the 1-month follow-up. Family history of diabetes was positively correlated (r=0.7) with lowered blood glucose level at week 8.