Abnormal diurnal weight gain among chronically psychotic patients contrasted with acutely psychotic patients and normals.

We found diurnal weight gain to be abnormal among 28 institutionalized chronically psychotic patients. They were weighed daily for 15 days at 7 a.m. and 4 p.m. 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. NDWG was 2.8 +/- 1.3% for the 28 study patients, 0.631 +/- 0.405% for 16 acutely psychotic controls, and 0.511 +/- 0.351% for 29 normals. Ninety-three per cent of the study sample had NDWG values above the upper limit of normal. Sex, diagnosis, smoking, baseline weight, blood pressure, and pulse did not explain these observations. NDWG related (N = 28, r = 0.552, P = 0.002) to antipsychotic drug dose. The implications of our findings are discussed.