title: Inhibition/activation in bipolar disorder: validation of the Multidimensional Assessment of Thymic States scale (MAThyS).
abstract: BACKGROUND
  One of the major issues in clinical practice is the accurate differential diagnosis between mixed states and depression, often leading to inappropriate prescriptions of antidepressants in mixed states, and as a consequence, increasing the risk of manic switch and suicide. In order to better define the spectrum of mixed states, it may be useful to develop a dimensional approach. In this context, the MAThyS (Multidimensional Assessment of Thymic States) scale was built to assess activation/inhibition levels in all bipolar mood episodes, and to determine whether a clinical description in terms of activation/inhibition can help better define bipolar states with which both manic and depressive symptoms are associated. The aim of this paper is the validation of the MAThyS scale in 141 bipolar patients in acute states (manic, hypomanic, mixed, or depressive).
  
  
  METHODS
  The validation of the MAThyS scale was the primary outcome of this 24-week, phase III, open-label, olanzapine single-arm clinical trial. Principal component, factorial analysis, and Cronbach's coefficient calculation (internal consistency) were performed. Concurrent validity (correlations with 17-item Hamilton Depression Rating Scale [HAMD-17], Hamilton Anxiety Rating Scale [HAMA], and Young Mania Rating Scale [YMRS]) and responsiveness to the clinical intervention were assessed (change in MAThyS scale and effect size) at 6 and 24 weeks.
  
  
  RESULTS
  Scree plot of eigenvalues identified a 2-dimension structure ("activation/inhibition level" and "emotional component"). Psychometric properties were good: Cronbach's coefficient was >0.9. Concurrent validity was good with low correlation (-0.19) with the HAMA scale and a higher correlation at baseline with the YMRS (0.72) and HAMD-17(-0.43). As expected, the activation state was predominant in manic, hypomanic, and mixed states while inhibition was predominant in depressive states. MAThyS score improvement was observed (effect size: -0.3 at 6 and 24 weeks).
  
  
  CONCLUSIONS
  The MAThyS demonstrated good psychometric properties. The MAThyS scale may help clinicians to better discriminate and follow bipolar episodes, especially the broad spectrum of mixed episodes.
authors.affiliation: INSERM, U995, IMRB, Department of Genetics, AP-HP, Henri Mondor-Albert Chenevier Group, Psychiatry, Univ Paris 12, Faculty of Medicine, IFR10, Créteil, France.
authors.forename: Chantal
authors.initials: C
authors.lastname: Henry
authors.forename: Amandine
authors.initials: A
authors.lastname: Luquiens
authors.forename: Christophe
authors.initials: C
authors.lastname: Lançon
authors.forename: Hélène
authors.initials: H
authors.lastname: Sapin
authors.forename: Marcel
authors.initials: M
authors.lastname: Zins-Ritter
authors.forename: Stephanie
authors.initials: S
authors.lastname: Gerard
authors.forename: Elena
authors.initials: E
authors.lastname: Perrin
authors.forename: Bruno
authors.initials: B
authors.lastname: Falissard
authors.forename: Michael
authors.initials: M
authors.lastname: Lukasiewicz
mesh_terms: D014150:Antipsychotic Agents / Q000627:therapeutic use; D001569:Benzodiazepines / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000188:drug therapy; D003863:Depression / Q000175:diagnosis; D005163:Factor Analysis, Statistical; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D025341:Principal Component Analysis; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D015203:Reproducibility of Results
chemical_list: D014150:Antipsychotic Agents; D001569:Benzodiazepines; D000077152:Olanzapine