Failure of antipsychotic drug dose to explain abnormal diurnal weight gain among 129 chronically psychotic inpatients.

1. The diurnal weight gain was found to be abnormal among 129 chronically psychotic inpatients. 2. The patients were weighed at 7 a.m. and 4 p.m. weekly for three weeks. We normalized the diurnal weight gain (NDWG) as a percentage by subtracting the 7 a.m. weight from the 4 p.m. weight, multiplying the difference by 100, and then dividing the result by the 7 a.m. weight. 3. NDWG was 2.2 +/- 1.5 percent for 87 male patients compared (p less than .0001) with .53 +/- .41 for 14 male controls. 4. NDWG was 1.8 +/- 1.0 percent for 42 female patients compared (p less than .0001) with .49 +/- .30 for 15 female controls. 5. Seventy percent of male and female patients had NDWG values greater than two standard deviations above the mean values of controls. 6. Differences in age, sex, morning weight, antipsychotic drugs, lithium, carbamazepine, phenytoin, blood pressure, and pulse did not explain these findings.