title: Platelet GSK3B activity in patients with late-life depression: marker of depressive episode severity and cognitive impairment?
abstract: OBJECTIVE
  Increased GSK3B activity has been reported as a state marker of major affective episodes in patients with depression and bipolar disorder. No study so far has addressed GSK3B activity in late-life depression. The aims of the present study were to determine GSK3B activity in platelets of elderly patients with major depression, and the association between GSK3B activity and the severity of depressive symptoms and cognitive impairment.
  
  
  METHODS
  Forty drug-free elderly patients with major depressive episode were compared to healthy older adults (n = 13). Severity of the depressive episode and current cognitive state were determined by the Hamilton Depression Scale (HAM-D) and the Cambridge Cognitive Test (CAMCOG), respectively. Total- and ser-9-phosphorylated GSK3B (tGSK3B and pGSK3B) were determined in platelets by enzyme immunometric assays (EIA). GSK3B activity was indirectly inferred by the GSK3B ratio (i.e. pGSK3B/tGSK3B).
  
  
  RESULTS
  Elderly depressed patients had significantly lower pGSK3B levels (P = 0.03) and GSK3B ratio (P = 0.03), indicating higher GSK3B activity. Higher GSK3B activity were observed in patients with severe depressive episode (HAM-D scores >22, P = 0.03) and with cognitive impairment (CAMCOG scores <86, P = 0.01).
  
  
  CONCLUSIONS
  The present findings provide additional evidence of the involvement of GSK3B in the pathophysiology of late-life major depression. Higher GSK3B activity may be more relevant in those patients with more severe depressive symptoms and cognitive impairment.
authors.affiliation: Laboratory of Neuroscience - LIM 27, Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, São Paulo, Brazil. brenosatler@usp.br
authors.forename: Breno Satler
authors.initials: BS
authors.lastname: Diniz
authors.forename: Leda Leme
authors.initials: LL
authors.lastname: Talib
authors.forename: Helena Passarelli Giroud
authors.initials: HP
authors.lastname: Joaquim
authors.forename: Vanessa Rodrigues Jesus
authors.initials: VR
authors.lastname: de Paula
authors.forename: Wagner Farid
authors.initials: WF
authors.lastname: Gattaz
authors.forename: Orestes Vicente
authors.initials: OV
authors.lastname: Forlenza
mesh_terms: D000342:Affective Symptoms; D017668:Age of Onset; D000368:Aged; D015415:Biomarkers; D001792:Blood Platelets / Q000201:enzymology*; D003865:Major Depressive Disorder / Q000453:epidemiology / Q000378:metabolism / Q000523:psychology; D005260:Female; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D016743:Mental Competency; D011569:Psychiatric Status Rating Scales; D012720:Severity of Illness Index; D012737:Sex Factors; D028761:Withholding Treatment
chemical_list: D015415:Biomarkers; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3