title: Platelet serotonergic predictors of clinical improvement in obsessive compulsive disorder.
abstract: OBJECTIVE
  Serotonin reuptake inhibitors (SRIs) are the most efficient pharmacological treatment of obsessive-compulsive disorders (OCD). Previous studies have suggested that some peripheral serotonergic parameters can be used to predict the clinical outcome of the treatment of OCD patients with SRIs. We tried to identify further peripheral serotonergic parameters that could help predict the clinical outcome of SRI treatment in a sample of patients with OCD.
  
  
  METHODS
  We compared 19 OCD patients before and after 8 weeks of SRI treatment with 19 sex-matched and age-matched controls. We assessed clinical improvement and whole-blood serotonin (5-HT) concentration, platelet 5-HT transporter (5-HTT) and 5-HT2A receptor binding characteristics and platelet IP3 content.
  
  
  RESULTS
  Before treatment, OCD patients had higher platelet IP3 content and fewer 5-HTT binding sites than the controls. Treatment with SRIs further lowered the number of 5-HTT binding sites, normalized platelet IP3 contents, and lowered the number of platelet 5-HT2A binding sites and whole-blood 5-HT concentrations below control values. The patients who improved most following SRI treatment had higher whole-blood 5-HT concentrations before treatment.
  
  
  CONCLUSIONS
  Our results confirm that whole-blood 5-HT concentration is a predictor for clinical improvement and indicate that abnormal intracellular mechanisms may be involved in OCD patients, in particular, the overstimulation of the phosphoinositide signaling system.
authors.affiliation: Service de Psychopathologie de l'Enfant et de l'adolescent, AP-HP, Hôpital Robert Debré, Paris, France.
authors.forename: Richard
authors.initials: R
authors.lastname: Delorme
authors.forename: Nadia
authors.initials: N
authors.lastname: Chabane
authors.forename: Jacques
authors.initials: J
authors.lastname: Callebert
authors.forename: Bruno
authors.initials: B
authors.lastname: Falissard
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Mouren-Siméoni
authors.forename: Frédéric
authors.initials: F
authors.lastname: Rouillon
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Launay
authors.forename: Marion
authors.initials: M
authors.lastname: Leboyer
mesh_terms: D000293:Adolescent; D000328:Adult; D001665:Binding Sites / Q000187:drug effects / Q000502:physiology; D015415:Biomarkers / Q000737:chemistry; D001792:Blood Platelets / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D002352:Carrier Proteins / Q000097:blood / Q000737:chemistry; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002648:Child; D004032:Diet; D005260:Female; D005602:France; D006801:Humans; D007099:Imipramine / Q000378:metabolism / Q000494:pharmacology; D007295:Inositol Phosphates / Q000737:chemistry / Q000378:metabolism; D007456:Iodine Isotopes / Q000737:chemistry / Q000493:pharmacokinetics; D008238:Lysergic Acid Diethylamide / Q000378:metabolism / Q000494:pharmacology; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood / Q000737:chemistry; D026901:Membrane Transport Proteins; D008875:Middle Aged; D009419:Nerve Tissue Proteins; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis* / Q000188:drug therapy; D017374:Paroxetine / Q000378:metabolism / Q000494:pharmacology; D011569:Psychiatric Status Rating Scales; D011854:Radiochemistry; D044402:Receptor, Serotonin, 5-HT2A / Q000737:chemistry / Q000502:physiology; D012701:Serotonin / Q000097:blood; D050486:Serotonin Plasma Membrane Transport Proteins; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use; D016896:Treatment Outcome; D014316:Tritium; D014364:Tryptophan / Q000378:metabolism
chemical_list: D015415:Biomarkers; D002352:Carrier Proteins; D007099:Imipramine; D007295:Inositol Phosphates; D007456:Iodine Isotopes; D008238:Lysergic Acid Diethylamide; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D017374:Paroxetine; D044402:Receptor, Serotonin, 5-HT2A; D012701:Serotonin; D050486:Serotonin Plasma Membrane Transport Proteins; D017367:Selective Serotonin Reuptake Inhibitors; D014316:Tritium; D014364:Tryptophan; C493230:SLC6A4 protein, human