A significant correlation between ward temperature and the severity of symptoms in schizophrenia inpatients — A longitudinal study

Abstract Background: Preliminary data suggest that schizophrenia outpatients' mental status might be affected, at least to some extent, by environmental temperature. To further substantiate the potential role of environmental temperature and schizophrenic symptoms we examined, in a naturalistic design, the relationship between environmental temperature of schizophrenia inpatients (i.e., ward temperature) and their mental status. Methods: Mean daily temperature of a closed psychiatric ward was monitored for 32 consecutive weeks. Temperature assessments were performed at 3 different locations within the ward at the same hour daily. Mean daily temperature was defined as the average of the 3 values. During each of the 32 weeks of the study, the inpatients were divided into two sub-groups: schizophrenia patients ( n = 22–34 patients/week) and non-schizophrenia psychotic patients ( n = 5–12 patients/week). The mental status of all participants was evaluated weekly using the positive and negative syndrome scale (PANSS). All participants were treated with antipsychotics during the entire study period. Results: Schizophrenia patients' total PANSS score, as well as each of the PANSS' subscales (positive, negative, general psychopathology, depression) were positively and significantly correlated with ward temperature ( r = 0.52–0.64; p = 0.002–0.0001). No correlation was found between ward temperature and any of the PANSS' subscales in the non-schizophrenia psychotic subjects. Conclusion: Our results suggest that schizophrenia inpatients' mental status might be modulated, at least to some extent, by environmental (i.e., ward) temperature and that this phenomenon is specific to schizophrenia patients. Our findings imply the need for optimally adjusting ward temperature (e.g., about 19 °C in this study) for the management of patients with acute psychotic exacerbation of schizophrenia.