RESUMO
We found abnormal diurnal weight gain among 25% of acutely psychotic patients with schizophrenia and 68% of chronically psychotic patients with schizophrenia. They were weighed at 7:00 AM and 4:00 PM weekly for 3 weeks. We normalized the diurnal weight gain (NDWG) as a percentage by subtracting the 7:00 AM weight from the 4:00 PM weight, multiplying the difference by 100, and dividing the result by the 7:00 AM weight, NDWG was 0.93% +/- 0.89% for the 36 acutely psychotic patients and 2.2% +/- 1.5% for the 68 chronically psychotic patients (F = 25.297, p less than 0.0001). Drugs did not explain this difference. Our data, though preliminary, suggest that water dysregulation, as manifested by abnormal diurnal weight gain, develops in schizophrenia as patients progress into Arieti's third stage of this disorder. A longitudinal study design, rather than our cross-sectional one, would be necessary to assess developmental changes in schizophrenia.