title: The association of depression with platelet activation: evidence for a treatment effect.
abstract: BACKGROUND
  Depression is associated with an increased risk of cardiovascular disease (CVD). Although the mechanism is uncertain, prothrombotic and inflammatory factors may play a role.
  
  
  OBJECTIVE
  As platelets play a key role in CVD, we determined first, whether depressed individuals had more activated platelets than non-depressed individuals and second, whether treatment of depression reduced platelet activation levels.
  
  
  METHODS
  We recruited 108 depressed outpatients and 45 control subjects all without a history of CVD. After psychological assessment, the depressed patients were offered treatment with medication and/or psychotherapy. Flow cytometric markers of platelet activation and level of depression were assessed at baseline and at 4 weeks and 6 months after treatment.
  
  
  RESULTS
  Depression was associated with increased platelet activation with a higher number of circulating CD62p (0.76x10(9) L(-1) vs. 0.46, P=0.019) and CD63 (P=0.05) positive platelets compared with controls. Patients with depression also had more circulating platelet-leukocyte aggregates than controls (P<0.001). There was a positive correlation between the severity of depression and the level of platelet activation. Platelets from depressed patients were also hyperreactive to adenosine 5 -diphosphate (ADP) stimulation with increased CD62p and CD63 exposure (P=0.003 and 0.019, respectively). Six months of treatment resulted in a reduced number of circulating CD62p and CD63 positive platelets (29.84% and 53.38% decrease) and a 20.9% reduction in CD63 exposure after ADP activation.
  
  
  CONCLUSIONS
  Depression is associated with increased in vivo platelet activation and resolution of depression using psychotherapy and/or medication reduces platelet activation. These findings provide insights into the link between depression and cardiovascular risk.
authors.affiliation: Northern Blood Research Centre, Department of Haematology and Transfusion Medicine, University of Sydney, Sydney, NSW, Australia. mmorelko@med.usyd.edu.au
authors.forename: M-C
authors.initials: MC
authors.lastname: Morel-Kopp
authors.forename: L
authors.initials: L
authors.lastname: McLean
authors.forename: Q
authors.initials: Q
authors.lastname: Chen
authors.forename: G H
authors.initials: GH
authors.lastname: Tofler
authors.forename: C
authors.initials: C
authors.lastname: Tennant
authors.forename: V
authors.initials: V
authors.lastname: Maddison
authors.forename: C M
authors.initials: CM
authors.lastname: Ward
mesh_terms: D000328:Adult; D000928:Antidepressive Agents / Q000494:pharmacology / Q000627:therapeutic use; D015703:Antigens, CD / Q000032:analysis; D002318:Cardiovascular Diseases / Q000209:etiology; D016022:Case-Control Studies; D003863:Depression / Q000097:blood* / Q000150:complications / Q000628:therapy*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D019007:P-Selectin / Q000032:analysis; D015539:Platelet Activation / Q000187:drug effects; D010980:Platelet Membrane Glycoproteins / Q000032:analysis; D011613:Psychotherapy; D060149:Tetraspanin 30
chemical_list: D000928:Antidepressive Agents; D015703:Antigens, CD; C554586:CD63 protein, human; D019007:P-Selectin; D010980:Platelet Membrane Glycoproteins; D060149:Tetraspanin 30