title: m-Chlorophenylpiperazine effects in neuroleptic-free schizophrenic patients. Evidence implicating serotonergic systems in the positive symptoms of schizophrenia.
abstract: OBJECTIVE
  This study evaluated whether alterations in serotonin function in schizophrenic patients could be demonstrated by comparing the reactivity to a serotonin partial agonist, m-chlorophenylpiperazine (MCPP) in patients and healthy subjects. This study also assessed whether stimulation of serotonin receptors influenced the symptoms of schizophrenia.
  
  
  METHODS
  Double-blind randomized comparison of MCPP (0.1 mg/kg, intravenously, administered over 20 minutes) and placebo effects in patients and healthy subjects.
  
  
  METHODS
  Department of Veterans Affairs Medical Center, West Haven, Conn. PATIENTS AND HEALTHY SUBJECTS: Fifteen healthy subjects recruited by public advertisement and 12 schizophrenic inpatients who had been neuroleptic free for at least 2 weeks prior to entry into the study.
  
  
  METHODS
  The principal outcome variable was the positive symptoms of schizophrenia operationally defined as the sum of scores on the four key items for schizophrenia on the Brief Psychiatric Rating Scale and the Brief Psychiatric Rating Scale thought disorder factor. Anxiety was assessed with a clinician-rated visual analog scale and plasma hormone levels were measured.
  
  
  RESULTS
  m-Chlorophenylpiperazine significantly increased the positive symptoms of schizophrenia in patients but not healthy subjects. Patients and healthy subjects exhibited anxiety increases of comparable magnitude following MCPP. However, patients had higher baseline levels of anxiety and exhibited more prolonged anxiogenic responses to MCPP. Anxiety elevations did not correlate with increases in the four key symptoms in patients. Patients exhibited lower baseline prolactin levels compared with healthy subjects, but the two groups did not differ in their prolactin, growth hormone, and cortisol responses to MCPP.
  
  
  CONCLUSIONS
  Schizophrenics, the only psychotic patient group studied to date, are the first patient group to exhibit propsychotic responses to MCPP. These data provide further evidence that serotonin systems modulate positive symptoms in some schizophrenic patients.
authors.affiliation: Department of Psychiatry, Yale University School of Medicine, West Haven, Conn.
authors.forename: J H
authors.initials: JH
authors.lastname: Krystal
authors.forename: J P
authors.initials: JP
authors.lastname: Seibyl
authors.forename: L H
authors.initials: LH
authors.lastname: Price
authors.forename: S W
authors.initials: SW
authors.lastname: Woods
authors.forename: G R
authors.initials: GR
authors.lastname: Heninger
authors.forename: G K
authors.initials: GK
authors.lastname: Aghajanian
authors.forename: D S
authors.initials: DS
authors.lastname: Charney
mesh_terms: D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D004311:Double-Blind Method; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D010879:Piperazines / Q000494:pharmacology*; D010919:Placebos; D011388:Prolactin / Q000097:blood; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D012565:Schizophrenic Psychology; D012701:Serotonin / Q000502:physiology*
chemical_list: D014150:Antipsychotic Agents; D010879:Piperazines; D010919:Placebos; D012701:Serotonin; D011388:Prolactin; D013006:Growth Hormone; C015068:1-(3-chlorophenyl)piperazine; D006854:Hydrocortisone