Short-term Ambient Fine Particulate Matter and Anxiety Symptoms in Adolescents with Generalized Anxiety Disorder

Abstract

Background: Short-term ambient fine particulate matter has been associated with exacerbations of psychiatric disorders in children and adolescents as measured by psychiatric emergency department utilizations. It is currently unknown if a similar association is seen with a continuous measure of symptom severity. We sought to determine if anxiety symptoms in adolescents with moderate-to-severe generalized anxiety disorder (GAD) were related to short-term ambient fine particulate matter concentrations.Methods: An analysis of participants receiving a placebo in an ongoing clinical trial (FiESTAA; clinicaltrials.gov identifier: NCT02818751) designed to test the efficacy of a medication in pediatric GAD was conducted. The severity of anxiety symptoms was assessed weekly over 8 weeks using the Pediatric Anxiety Rating Scale (PARS) score administered by a psychiatrist. Participants’ geocoded residential addresses and PARS assessment dates were used to estimate short-term ambient concentrations of particulate matter smaller than 2.5 µm (PM2.5) using a previously validated spatiotemporal model. A Poisson fixed effects regression model with a participant-specific intercept was used to estimate the increase in PARS corresponding to a doubling in total ambient PM2.5 concentrations two and three days prior to PARS assessment while adjusting for temperature and humidity.Results: A subset of FiESTAA participants with currently available data (n = 5) representing 33 total PARS assessments were analyzed. A doubling of the total ambient PM2.5 concentrations two and three days prior to the assessment were associated with a 1.21 fold increase (95% CI: 0.98, 1.48) in the PARS score.Conclusions: These results will be replicated using the full FiESTAA dataset and within an additional clinical trial for GAD when all data is available. Initial results suggest that short-term ambient air pollution may influence the severity of anxiety symptoms in adolescents with GAD and future work should examine the impact of ambient air pollution on the pathoetiology of anxiety disorders.