title: Prospective assessment of neuropsychological functioning and mood in US Army National Guard personnel deployed as peacekeepers.
abstract: OBJECTIVE
  The present study examined the impact of deployment on neuropsychological functioning and mood in Army National Guard personnel. We hypothesized that deployment on a peacekeeping mission, compared to non-deployment, would result in reduced proficiencies in neuropsychological performance and negative mood changes, and that such changes would relate to working in a high-strain job (high demands/low control), in accordance with Karasek's demand-control model.
  
  
  METHODS
  This prospective cohort study involved 119 male soldiers (67 participants examined before and after deployment to the Bosnia operational theatre and 52 non-deployed soldiers assessed twice over a comparable period).
  
  
  RESULTS
  Unit-level adjusted, multivariate analyses found that deployed soldiers, compared to their non-deployed counterparts, demonstrated reduced proficiency in tasks involving motor speed [unstandardized coefficient B= -3.88, 95% confidence interval (95% CI) -6.38- -1.39; B= -3.84, 95% CI -5.55- -2.14; dominant and non-dominant hand, respectively] and sustained attention (B=0.031, 95% CI 0.009-0.054), along with decreased vigor (B= -2.71, 95% CI -3.63- -1.77). Deployed soldiers also showed improved proficiency in a working-memory task (B= -0.098, 95% CI -0.136- -0.060) with less depression symptomatology (B= -3.19, 95% CI -5.26- -1.13). Work stress levels increased over time in both deployed and non-deployed groups, but observed deployment effects remained significant after accounting for a high-strain job.
  
  
  CONCLUSIONS
  The observed change in performance associated with peacekeeping deployment compared to non-deployment (slowed processing speed, reduced motor speed and reported vigor, together with improved proficiency in a working memory task) suggests an adaptive response to mission occupational stressors. This pattern does not appear to be influenced by working in a high-strain job. Further study is required to examine whether these results reflect transient or permanent changes in functioning.
authors.affiliation: Military Performance Division, US Army Research Institute of Environmental Medicine, Kansas St, Building 42, Natick, MA 01760, United States. susan.proctor@us.army.mil
authors.forename: Susan P
authors.initials: SP
authors.lastname: Proctor
authors.forename: Kristin J
authors.initials: KJ
authors.lastname: Heaton
authors.forename: Kathryn Dutille
authors.initials: KD
authors.lastname: Dos Santos
authors.forename: Erik S
authors.initials: ES
authors.lastname: Rosenman
authors.forename: Timothy
authors.initials: T
authors.lastname: Heeren
mesh_terms: D000339:Affect; D000367:Age Factors; D006304:Health Status; D006801:Humans; D008297:Male; D008603:Mental Health; D008889:Military Personnel / Q000523:psychology*; D009483:Neuropsychological Tests; D009784:Occupational Diseases / Q000453:epidemiology*; D016272:Occupational Health; D011446:Prospective Studies; D012959:Socioeconomic Factors; D013315:Stress, Psychological / Q000453:epidemiology*; D014481:United States