Air Pollution and Symptom Severity in Hospitalized Subjects with Schizophrenia Spectrum Disorders

Air pollution has been demonstrated to represent a major threat to mental health, leading to higher risk of development or exacerbation of serious psychiatric disorders. The current study was aimed at investigating the associations between air pollutant concentrations (particulate matter 2.5 and 10, ozone, carbon monoxide, nitrogen dioxide) and symptom severity in a sample of inpatients suffering from schizophrenia spectrum disorders. We collected sociodemographic, clinical, and psychopathological characteristics of subjects (n=118) with schizophrenia spectrum disorders who were hospitalized in the Psychiatric Inpatient Unit of the University Hospital of Perugia in the period 1^stJanuary 2015-31^stDecember 2016. Psychopathological characteristics were assessed using the Positive And Negative Syndrome Scale (PANSS), the Brief Psychiatric Rating Scale (BPRS) and the Clinical Global impressions (CGI) scale. Hierarchical multiple regressions were run to assess the association between air pollutants concentrations and the PANSS, BPRS, and CGI total subscale scores, controlling the analyses for sex/age and meteorological data. We found a significant positive association between the average concentration of ozone before admission and the anxiety-depression factor score domain at the PANSS. No significant associations between the other pollutants and the different scores at the scales used for the psychopathological assessment were found. Short-term exposure to ozone may influence the clinical presentation of schizophrenia spectrum disorders and should be thus considered among the potentially modifiable risk factors in the urban environment. Air pollution should be considered among the main threats to human mental health and policymakers should address the built of sustainable urban environments.