title: Novel surveillance of psychological distress during the great recession.
abstract: BACKGROUND
  Economic stressors have been retrospectively associated with net population increases in nonspecific psychological distress (PD). However, no sentinels exist to evaluate contemporaneous associations. Aggregate Internet search query surveillance was used to monitor population changes in PD around the United States' Great Recession.
  
  
  METHODS
  Monthly PD query trends were compared with unemployment, underemployment, homes in delinquency and foreclosure, median home value or sale prices, and S&P 500 trends for 2004-2010. Time series analyses, where economic indicators predicted PD one to seven months into the future, were performed in 2011.
  
  
  RESULTS
  PD queries surpassed 1,000,000 per month, of which 300,000 may be attributable to the Great Recession. A one percentage point increase in mortgage delinquencies and foreclosures was associated with a 16% (95%CI, 9-24) increase in PD queries one-month, and 11% (95%CI, 3-18) four months later, in reference to a pre-Great Recession mean. Unemployment and underemployment had similar associations half and one-quarter the intensity. "Anxiety disorder", "what is depression", "signs of depression", "depression symptoms", and "symptoms of depression" were the queries exhibiting the strongest associations with mortgage delinquencies and foreclosures, unemployment or underemployment. Housing prices and S&P 500 trends were not associated with PD queries.
  
  
  CONCLUSIONS
  A non-traditional measure of PD was used. It is unclear if actual clinically significant depression or anxiety increased during the Great Recession. Alternative explanations for strong associations between the Great Recession and PD queries, such as media, were explored and rejected.
  
  
  CONCLUSIONS
  Because the economy is constantly changing, this work not only provides a snapshot of recent associations between the economy and PD queries but also a framework and toolkit for real-time surveillance going forward. Health resources, clinician screening patterns, and policy debate may be informed by changes in PD query trends.
authors: Children's Hospital Informatics Program at the Harvard-MIT Division of Health Sciences and Technology, Boston, MA, USA. john.ayers@childrens.harvard.edu
authors: John W
authors: JW
authors: Ayers
authors: Benjamin M
authors: BM
authors: Althouse
authors: Jon-Patrick
authors: JP
authors: Allem
authors: Matthew A
authors: MA
authors: Childers
authors: Waleed
authors: W
authors: Zafar
authors: Carl
authors: C
authors: Latkin
authors: Kurt M
authors: KM
authors: Ribisl
authors: John S
authors: JS
authors: Brownstein
mesh_terms: D000328:Adult; D001007:Anxiety / Q000453:epidemiology; D003863:Depression / Q000453:epidemiology; D003866:Depressive Disorder / Q000453:epidemiology; D057172:Economic Recession / Q000706:statistics & numerical data / Q000639:trends*; D004651:Employment / Q000706:statistics & numerical data / Q000639:trends; D006801:Humans; D001523:Mental Disorders / Q000453:epidemiology*; D018803:Models, Economic; D011159:Population Surveillance; D012189:Retrospective Studies; D013315:Stress, Psychological / Q000453:epidemiology*; D014478:Unemployment / Q000523:psychology; D014481:United States / Q000453:epidemiology