title: Validation of a diagnostic screening blood test for bipolar disorder.
abstract: BACKGROUND
  Bipolar disorder is difficult to diagnose, and probably is both overdiagnosed and underdiagnosed. Misdiagnosis has deleterious consequences for the prognosis of the disorder. In a previous study (n = 134), measurement of blood cellular membrane potential (expressed as membrane potential ratio [MPR™]) diagnosed bipolar illness with a sensitivity of .78 and a specificity of .88. The current study was performed as a validation of the initial study.
  
  
  METHODS
  We recruited consecutive outpatients with DSM-IV-diagnosed bipolar I disorder (BD I) and those without bipolar illness (n = 153) and measured their MPR™.
  
  
  RESULTS
  BD I patients were relatively hyperpolarized, with an MPR™ of .601 (± standard deviation .0179), compared with non-bipolar patients (MPR™ .675 ± .0174). The sensitivity and specificity for BD I are .93 and .90, respectively.
  
  
  CONCLUSIONS
  Before clinical application, future studies must utilize consensus diagnosis as the "gold standard" diagnosis and examine the effect of mood-stabilizing drugs on MPR™.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, Louisville, KY 40202, USA.
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Woodruff
authors.forename: Rif S
authors.initials: RS
authors.lastname: El-Mallakh
authors.forename: Alagu P
authors.initials: AP
authors.lastname: Thiruvengadam
mesh_terms: D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000097:blood / Q000175:diagnosis*; D002648:Child; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008564:Membrane Potentials / Q000502:physiology*; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012680:Sensitivity and Specificity