title: Compounds containing cytosolic choline in the basal ganglia: a potential biological marker of true drug response to fluoxetine.
abstract: OBJECTIVE
  Studies have identified two types of antidepressant response: true drug response and placebo pattern response. This study examined the relationship between true drug response and choline-creatine ratios in the basal ganglia of depressed patients treated with fluoxetine.
  
  
  METHODS
  The authors evaluated drug-free outpatients with major depression before (N = 41) and after (N = 15) 8 weeks of fluoxetine treatment, 20 mg/day, by using proton magnetic resonance spectroscopy.
  
  
  RESULTS
  There was a significant difference in the degree of change from baseline to week 8 in choline-creatine ratios between the true drug response group (N = 8) and the placebo pattern response/nonresponse group (N = 7); the true drug response patients had a 20% increase in choline-creatine ratios, and the placebo pattern response/nonresponse patients had a 12% decrease in choline-creatine ratios.
  
  
  CONCLUSIONS
  These data suggest that true drug response to fluoxetine treatment in depression may be associated with an increase in choline-creatine ratios in the basal ganglia.
authors.affiliation: Depression Clinical and Research Program, Massachusetts General Hospital, Harvard Medical School, USA.
authors.forename: S B
authors.initials: SB
authors.lastname: Sonawalla
authors.forename: P F
authors.initials: PF
authors.lastname: Renshaw
authors.forename: C M
authors.initials: CM
authors.lastname: Moore
authors.forename: J E
authors.initials: JE
authors.lastname: Alpert
authors.forename: A A
authors.initials: AA
authors.lastname: Nierenberg
authors.forename: J F
authors.initials: JF
authors.lastname: Rosenbaum
authors.forename: M
authors.initials: M
authors.lastname: Fava
mesh_terms: D000328:Adult; D000553:Ambulatory Care; D000704:Analysis of Variance; D001479:Basal Ganglia / Q000737:chemistry* / Q000187:drug effects*; D015415:Biomarkers; D002794:Choline / Q000032:analysis* / Q000378:metabolism; D003401:Creatine / Q000032:analysis* / Q000378:metabolism; D003600:Cytosol / Q000737:chemistry* / Q000187:drug effects; D003866:Depressive Disorder / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D005473:Fluoxetine / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D010919:Placebos; D011569:Psychiatric Status Rating Scales; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D010919:Placebos; D005473:Fluoxetine; D003401:Creatine; D002794:Choline