title: Pituitary volume and early treatment response in drug-naïve first-episode psychosis patients.
abstract: BACKGROUND
  An early response to antipsychotic treatment in patients with psychosis has been associated with a better course and outcome. However, factors that predict treatment response are not well understood. The onset of schizophrenia and related disorders has been associated with increased levels of stress and hyper-activation of the hypothalamic-pituitary-adrenal (HPA) axis. This study examined whether pituitary volume at the onset of psychosis may be a potential predictor of early treatment response in first-episode psychosis (FEP) patients.
  
  
  METHODS
  We investigated the relationship between baseline pituitary volume and symptomatic treatment response over 12 weeks using mixed model analysis in a sample of 42 drug-naïve or early treated FEP patients who participated in a controlled dose-finding study of quetiapine fumarate. Logistic regression was used to examine predictors of treatment response. Pituitary volume was measured from magnetic resonance imaging scans that were obtained upon entry into the trial.
  
  
  RESULTS
  Larger pituitary volume was associated with less improvement in overall psychotic symptoms (Brief Psychiatric Rating Scale (BPRS) P=0.031) and positive symptoms (BPRS positive symptom subscale P=0.010). Regardless of gender, patients with a pituitary volume at the 25th percentile (413 mm(3)) were approximately three times more likely to respond to treatment by week 12 than those at the 75th percentile (635 mm(3)) (odds ratio=3.07, CI: 0.90-10.48).
  
  
  CONCLUSIONS
  The association of baseline pituitary volumes with early treatment response highlights the importance of the HPA axis in emerging psychosis. Potential implications for treatment strategies in early psychosis are discussed.
authors.affiliation: Orygen Youth Health - Research Centre, University of Melbourne, Australia. bagarner@unimelb.edu.au
authors.forename: B
authors.initials: B
authors.lastname: Garner
authors.forename: G E
authors.initials: GE
authors.lastname: Berger
authors.forename: J P
authors.initials: JP
authors.lastname: Nicolo
authors.forename: A
authors.initials: A
authors.lastname: Mackinnon
authors.forename: S J
authors.initials: SJ
authors.lastname: Wood
authors.forename: C M
authors.initials: CM
authors.lastname: Pariante
authors.forename: P
authors.initials: P
authors.lastname: Dazzan
authors.forename: T M
authors.initials: TM
authors.lastname: Proffitt
authors.forename: C
authors.initials: C
authors.lastname: Markulev
authors.forename: M
authors.initials: M
authors.lastname: Kerr
authors.forename: M
authors.initials: M
authors.lastname: McConchie
authors.forename: L J
authors.initials: LJ
authors.lastname: Phillips
authors.forename: C
authors.initials: C
authors.lastname: Pantelis
authors.forename: P D
authors.initials: PD
authors.lastname: McGorry
mesh_terms: D000293:Adolescent; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D003987:Dibenzothiazepines / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D015233:Models, Statistical; D010902:Pituitary Gland / Q000187:drug effects* / Q000473:pathology*; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000188:drug therapy* / Q000473:pathology*; D000069348:Quetiapine Fumarate; D012720:Severity of Illness Index; D013997:Time Factors; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D003987:Dibenzothiazepines; D000069348:Quetiapine Fumarate