Polydipsia, psychosis, and familial psychopathology

Objective: To compare the demographic and clinical factors and familial psy chopathology of chronic psychiatric inpatients with, and without, polydipsi a. Method. We undertook a case-control study of chronic psychiatric inpatients both with, and without, polydipsia. Clinical and demographic data were gat hered using a predesigned questionnaire, the Positive and Negative Syndrome Scale (PANSS), the Abnormal Involuntary Movement Scale (AIMS), the Mini-Me ntal State Examination Scale (MMSE), and the Family History-Research Diagno stic Criteria (FH-RDC). Results: The prevalence rate of polydipsia was 20.2%. The group with polydi psia was significantly younger, both at the time of their first-ever psychi atric and current psychiatric admissions, compared with the group without p olydipsia. The 2 groups were similar in terms of their illness characterist ics and psychiatric diagnoses. In the group with polydipsia, alcohol abuse predated the psychotic illness by a mean of 10.5 (SD 4.4) years, compared w ith 4.8 (SD 1.6) years for the same period in the unaffected group. The 2 g roups did not differ significantly regarding the antipsychotic medication d osage, the proportion on concomitant anticholinergic medication, the docume nted previous response to antipsychotic medication, or past treatment with electroconvulsive therapy (ECT). First-degree relatives of patients with po lydipsia were found to have significantly higher rates of alcohol dependenc e. Conclusion: This study provides further evidence for the higher rate of pol ydipsia among chronic psychiatric patient populations and for high rates of alcohol-related problems among their first-degree relatives.