title: Stress and the city: impact of urban upbringing on the (re)activity of the hypothalamus-pituitary-adrenal axis.
abstract: OBJECTIVE
  Urbanization is a major challenge for the 21st century with a significant impact on health; mental health, in particular, can be negatively affected. The mechanisms linking urban living to psychopathology, however, remain unclear. We tested the hypothesis that urban upbringing may alter the activity of the hypothalamus-pituitary-adrenal (HPA) axis, one of the body's major stress response systems.
  
  
  METHODS
  In three independent experiments (n = 248 in total), we measured the changes in cortisol, the end-product of the HPA axis, in response to different stress tasks (memory recall with critical social evaluation [Experiment 1] or Socially Evaluated Cold Pressor Test [Experiment 2] and to awakening in participants raised in cities or more rural areas.
  
  
  RESULTS
  Urban upbringing was associated with elevated cortisol responses to acute stress (task × time point of measurement × urbanicity interaction: F(2,132) = 3.10 [p = .048] in Experiment 1 and F(2,112) = 3.29 [p = .041] in Experiment 2) but with a blunted cortisol awakening response (time point of measurement × urbanicity interaction: F(1,114) = 4.00, p = .048). The autonomic stress response, as indicated by blood pressure measurements, was not affected by urban upbringing. Moreover, current city living was not associated with any changes in the physiological responses to stress or awakening.
  
  
  CONCLUSIONS
  Our findings suggest that urban upbringing changes the (re)activity of the HPA axis. Given that changes in HPA axis regulation have been associated with several psychiatric disorders, this may represent a mechanism that contributes to the increased risk for psychopathology in urban populations.
authors.affiliation: From the Institute of Experimental Psychology (V.S., K.A., P.S., L.S.), Department of Biological Psychology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.
authors.forename: Vera
authors.initials: V
authors.lastname: Steinheuser
authors.forename: Karina
authors.initials: K
authors.lastname: Ackermann
authors.forename: Pia
authors.initials: P
authors.lastname: Schönfeld
authors.forename: Lars
authors.initials: L
authors.lastname: Schwabe
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D010913:Pituitary-Adrenal System / Q000378:metabolism* / Q000503:physiopathology; D011897:Random Allocation; D013315:Stress, Psychological / Q000378:metabolism* / Q000503:physiopathology; D014505:Urban Population; D055815:Young Adult
chemical_list: D006854:Hydrocortisone