title: Persistent versus transient depressive symptoms in relation to platelet hyperactivation: a longitudinal analysis of dementia caregivers.
abstract: BACKGROUND
  Depressive symptoms and caregiving stress may contribute to cardiovascular disease (CVD) via chronic platelet activation; however, it remains unclear whether this elevated activation constitutes a trait or state marker. The primary objective was to investigate whether persistent depressive symptoms would relate to elevated platelet activation in response to acute psychological stress over a three-year period.
  
  
  METHODS
  Depressive symptoms (Brief Symptom Inventory) were assessed among 99 spousal dementia caregivers (52-88 years). Platelet P-selectin expression was assessed in vivo using flow cytometry at three time-points over the course of an acute stress test: baseline, post-stress, and after 14 min of recovery. Two competing structural analytic models of depressive symptoms and platelet hyperactivity with three yearly assessments were compared.
  
  
  RESULTS
  Although depressive symptoms were generally in the subclinical range, their persistent elevation was associated with heightened platelet reactivity and recovery at all three-years while the change in depressive symptoms from the previous year did not predict platelet activity.
  
  
  CONCLUSIONS
  These results focus on caregivers providing consistent home care, while future studies may extend these results by modeling major caregiving stressors.
  
  
  CONCLUSIONS
  Enduring aspects of negative affect, even among those not suffering from clinical depression are related to hemostatic changes, in this case platelet reactivity, which might be one mechanism for previously reported increase in CVD risk among elderly Alzheimer caregivers.
authors.affiliation: Department of Psychiatry, University of California, San Diego, USA.
authors.forename: Kirstin
authors.initials: K
authors.lastname: Aschbacher
authors.forename: Susan K
authors.initials: SK
authors.lastname: Roepke
authors.forename: Roland
authors.initials: R
authors.lastname: von Känel
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Mills
authors.forename: Brent T
authors.initials: BT
authors.lastname: Mausbach
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Patterson
authors.forename: Joel E
authors.initials: JE
authors.lastname: Dimsdale
authors.forename: Michael G
authors.initials: MG
authors.lastname: Ziegler
authors.forename: Sonia
authors.initials: S
authors.lastname: Ancoli-Israel
authors.forename: Igor
authors.initials: I
authors.lastname: Grant
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001792:Blood Platelets / Q000378:metabolism*; D017028:Caregivers / Q000523:psychology*; D003704:Dementia / Q000451:nursing*; D003863:Depression / Q000378:metabolism* / Q000523:psychology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008961:Models, Structural; D019007:P-Selectin / Q000378:metabolism*; D010555:Personality Inventory; D015539:Platelet Activation; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors; D013315:Stress, Psychological / Q000150:complications* / Q000523:psychology; D013997:Time Factors
chemical_list: D019007:P-Selectin