title: Predominant polarity in bipolar disorder and validation of the polarity index in a German sample.
abstract: BACKGROUND
  A large number of patients with bipolar disorder (BD) can be characterized by predominant polarity (PP), which has important implications for relapse prevention. Recently, Popovic et al. (EUR NEUROPSYCHOPHARM 22(5): 339-346, 2012) proposed the Polarity Index (PI) as a helpful tool in the maintenance treatment of BD. As a numeric expression, it reflects the efficacy of drugs used in treatment of BD. In the present retrospective study, we aimed to validate this Index in a large and well characterized German bipolar sample.
  
  
  METHODS
  We investigated 336 bipolar patients (BP) according to their PP and calculated the PI for each patient in order to prove if maintenance treatment differs according to their PP. Furthermore, we analysed whether PP is associated with demographic and clinical characteristics of BP.
  
  
  RESULTS
  In our sample, 63.9% of patients fulfilled criteria of PP: 169 patients were classified as depressive predominant polarity (DPP), 46 patients as manic predominant polarity (MPP). The two groups differed significantly in their drug regime: Patients with DPP were more often medicated with lamotrigine and antidepressants, patients with MPP were more often treated with lithium, valproate, carbamazepine and first generation antipsychotics. However, patients with DPP and MPP did not differ significantly with respect to the PI, although they received evidence-based and guideline-driven treatment.
  
  
  CONCLUSIONS
  The reason for this negative finding might well be that for several drugs, which were used frequently, no PI value is available. Nevertheless we suggest PP as an important concept in the planning of BD maintenance treatment.
authors.affiliation: Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wuerzburg, Fuechsleinstrasse 15, Wuerzburg, D-97080, Germany. Volkert_J@ukw.de.|Department of Psychiatry, Psychosomatic Medicine and Psychotherapy Goethe-University, Heinrich-Hoffmann-Straße 10, Frankfurt am Main, D-60528, Germany. Volkert_J@ukw.de.
authors.forename: Julia
authors.initials: J
authors.lastname: Volkert
authors.affiliation: Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wuerzburg, Fuechsleinstrasse 15, Wuerzburg, D-97080, Germany. Zierhut_K@ukw.de.
authors.forename: Kathrin C
authors.initials: KC
authors.lastname: Zierhut
authors.affiliation: Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wuerzburg, Fuechsleinstrasse 15, Wuerzburg, D-97080, Germany. E_Schiele_M@ukw.de.
authors.forename: Miriam A
authors.initials: MA
authors.lastname: Schiele
authors.affiliation: Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wuerzburg, Fuechsleinstrasse 15, Wuerzburg, D-97080, Germany. martina.wenzel@aol.de.
authors.forename: Martina
authors.initials: M
authors.lastname: Wenzel
authors.affiliation: Department of Psychiatry, Psychosomatic Medicine and Psychotherapy Goethe-University, Heinrich-Hoffmann-Straße 10, Frankfurt am Main, D-60528, Germany. Juliane.Kopf@kgu.de.
authors.forename: Juliane
authors.initials: J
authors.lastname: Kopf
authors.affiliation: Department of Psychiatry, Psychosomatic Medicine and Psychotherapy Goethe-University, Heinrich-Hoffmann-Straße 10, Frankfurt am Main, D-60528, Germany. Sarah.Kittel-Schneider@kgu.de.
authors.forename: Sarah
authors.initials: S
authors.lastname: Kittel-Schneider
authors.affiliation: Department of Psychiatry, Psychosomatic Medicine and Psychotherapy Goethe-University, Heinrich-Hoffmann-Straße 10, Frankfurt am Main, D-60528, Germany. Andreas.Reif@kgu.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Reif
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000928:Antidepressive Agents / Q000627:therapeutic use; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy* / Q000208:ethnology / Q000503:physiopathology; D002220:Carbamazepine / Q000627:therapeutic use; D005260:Female; D005858:Germany / Q000208:ethnology; D006801:Humans; D000077213:Lamotrigine; D018020:Lithium Compounds / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales / Q000592:standards; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014227:Triazines / Q000627:therapeutic use; D014635:Valproic Acid / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D000928:Antidepressive Agents; D014150:Antipsychotic Agents; D018020:Lithium Compounds; D014227:Triazines; D002220:Carbamazepine; D014635:Valproic Acid; D000077213:Lamotrigine