Increased urine volume in chronic schizophrenic patients

Area of Science:

• Psychiatry
• Endocrinology
• Clinical Medicine

Background:

• Polydipsia (excessive thirst) and polyuria (excessive urine volume) are frequently observed in individuals with schizophrenia.
• The precise prevalence and clinical significance of these symptoms in schizophrenia require further investigation.

Purpose of the Study:

• To determine the prevalence of polydipsia and polyuria in patients with chronic schizophrenia.
• To compare urine volume in medication-free schizophrenic patients with normal and nonschizophrenic controls.
• To explore associations between polyuria and clinical factors, including premorbid history, neuroleptic response, and hyponatremia.

Main Methods:

• Urine volume was measured in milliliters per 24 hours for three groups: medication-free chronic schizophrenic patients, nonschizophrenic patients, and normal controls.
• Statistical analysis was performed to compare mean urine volumes between groups.
• Polyuria was defined as urine volume exceeding the range observed in normal controls.

Main Results:

• Schizophrenic patients exhibited significantly higher mean 24-hour urine volumes (2319 ml) compared to nonschizophrenic patients (1054 ml) and normal controls (1265 ml).
• Seven out of 35 schizophrenic patients demonstrated polyuria, exceeding normal control ranges, while no nonschizophrenic patients did.
• Polyuria correlated with a favorable premorbid history and positive response to neuroleptic medication. Neuroleptic treatment further increased urine volume.

Conclusions:

• Polydipsia and polyuria are relatively common in schizophrenia.
• Polyuria in schizophrenia may be associated with a better clinical outlook and response to treatment.
• Hyponatremia in polyuric schizophrenic patients might signify a distinct subgroup requiring further study.