Examining the Relationship between Drought and Mental Health Outcomes of Depression and Anxiety in the U.S.

Abstract Examining the relationship between drought and mental health outcomes of depression and anxiety in the U.S. By Robyn J. Cathey December 4, 2017 BACKGROUND: Drought is likely linked to depression and anxiety through environmental and economic factors. Having a better understanding of this relationship would assist public health officials and policy-makers in future drought preparedness and mitigation strategies. METHODS: Depression and anxiety data were collected for 36 states from HCUPnet, an online system of hospital inpatient and emergency department information. Drought data were collected from the U.S. Drought Monitor, a weekly monitor integrating multiple drought indices to produce a single index, for 2011-2014. Proportions were calculated for state hospital mental health discharges from total state hospital discharges. Annual state drought data was dichotomized based on a 30% areal drought threshold for drought exposure conditions. Repeated measures ANOVA was used for analysis of the relationship between states’ depression and anxiety discharges and states’ drought exposure. RESULTS: The effect of time on depression was significantly different for states in the exposed and unexposed condition, F (3, 32) = 4.22, p = 0.01. The effect of time on anxiety was not different for states in the exposed and unexposed drought conditions, F (3, 32) = 1.92, p = 0.15. Post-hoc comparisons using four paired samples t-tests indicated a significant effect of drought exposure on depression comparing exposed drought condition with unexposed drought condition during 2011, 2012, 2013 and 2014. A significant effect of drought exposure condition on anxiety comparing exposed drought condition with unexposed drought condition during 2011, 2012, 2013 and 2014. CONCLUSION: Depression and anxiety discharges differed over time and between states in the exposed and unexposed drought conditions from 2011-2014. Depression and anxiety discharges were higher for states in the unexposed drought condition. Further research would refine the examination of this relationship

Elemental Fingerprinting of Mussel Shells to Predict Population Sources and Redistribution Potential in the Gulf of Maine

As the climate warms, species that cannot tolerate changing conditions will only persist if they undergo range shifts. Redistribution ability may be particularly variable for benthic marine species that disperse as pelagic larvae in ocean currents. The blue mussel, Mytilus edulis, has recently experienced a warming-related range contraction in the southeastern USA and may face limitations to northward range shifts within the Gulf of Maine where dominant coastal currents flow southward. Thus, blue mussels might be especially vulnerable to warming, and understanding dispersal patterns is crucial given the species' relatively long planktonic larval period (>1 month). To determine whether trace elemental “fingerprints” incorporated in mussel shells could be used to identify population sources (i.e. collection locations), we assessed the geographic variation in shell chemistry of blue mussels collected from seven populations between Cape Cod, Massachusetts and northern Maine. Across this ∼500 km of coastline, we were able to successfully predict population sources for over two-thirds of juvenile individuals, with almost 80% of juveniles classified within one site of their collection location and 97% correctly classified to region. These results indicate that significant differences in elemental signatures of mussel shells exist between open-coast sites separated by ∼50 km throughout the Gulf of Maine. Our findings suggest that elemental “fingerprinting” is a promising approach for predicting redistribution potential of the blue mussel, an ecologically and economically important species in the region