title: Test-retest reliability of a new questionnaire for the retrospective assessment of long-term lithium use in bipolar disorder.
abstract: BACKGROUND
  The identification of predictors of treatment response holds tremendous potential for the improvement of clinical outcomes in bipolar disorder (BP). The goal of this project is to evaluate the test-retest reliability of a new clinical tool, the Lithium Questionnaire (LQ), for the retrospective assessment of long-term lithium use in research participants with BP.
  
  
  METHODS
  Twenty-nine individuals with BP-I (n=27), major depression (n=1), or schizoaffective disorder (n=1) were recruited for participation. The LQ was administered to all participants at two time-points, spaced 17 months apart on average, and used to determine each subject׳s score on the Retrospective Criteria of Long-Term Treatment Response in Research Subjects with Bipolar Disorder Scale, or the Alda Scale. Scores were confirmed through a best-estimate procedure, and test-retest reliability (intra-class correlation coefficient [ICC]) of the LQ was calculated.
  
  
  RESULTS
  The correlation between the total Alda Scale scores at the two time-points was in the moderate range (ICC=0.60). Relevant clinical factors such as age or presence of Axis I psychiatric comorbidity did not influence the reliability.
  
  
  CONCLUSIONS
  The validity of the LQ was not examined. Inclusion of two participants with non-BP diagnoses may have affected the LQ׳s reliability, but re-analysis of our data after exclusion of these participants did not influence the reliability. The absence of measures of mood and cognition at time of LQ may be a limitation of this work.
  
  
  CONCLUSIONS
  The LQ holds promise for the standardization of the retrospective assessment of long-term treatment in BP.
authors.affiliation: University of Iowa Carver College of Medicine, Department of Psychiatry, Iowa City, IA, USA. Electronic address: sarah-k-tighe@uiowa.edu.
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Tighe
authors.affiliation: The Johns Hopkins University School of Medicine, Department of Psychiatry and Behavioral Sciences, Baltimore, MD, USA.
authors.forename: Megan
authors.initials: M
authors.lastname: Ritchey
authors.affiliation: The Johns Hopkins University School of Medicine, Department of Psychiatry and Behavioral Sciences, Baltimore, MD, USA.
authors.forename: Barbara
authors.initials: B
authors.lastname: Schweizer
authors.affiliation: The Johns Hopkins University School of Medicine, Department of Psychiatry and Behavioral Sciences, Baltimore, MD, USA.
authors.forename: Fernando S
authors.initials: FS
authors.lastname: Goes
authors.affiliation: The Johns Hopkins University School of Medicine, Department of Psychiatry and Behavioral Sciences, Baltimore, MD, USA.
authors.forename: Dean
authors.initials: D
authors.lastname: MacKinnon
authors.affiliation: The Johns Hopkins University School of Medicine, Department of Psychiatry and Behavioral Sciences, Baltimore, MD, USA.
authors.forename: Francis
authors.initials: F
authors.lastname: Mondimore
authors.affiliation: The Johns Hopkins University School of Medicine, Department of Psychiatry and Behavioral Sciences, Baltimore, MD, USA.
authors.forename: J
authors.initials: J
authors.lastname: Raymond DePaulo
authors.affiliation: Human Genetics Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Francis J
authors.initials: FJ
authors.lastname: McMahon
authors.affiliation: The Johns Hopkins University School of Medicine, Department of Psychiatry and Behavioral Sciences, Baltimore, MD, USA; Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Germany; Institute of Psychiatric Phenomics and Genomics, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Schulze
authors.affiliation: The Johns Hopkins University School of Medicine, Department of Psychiatry and Behavioral Sciences, Baltimore, MD, USA; The Johns Hopkins University Bloomberg School of Public Health, Department of Mental Health, Baltimore, MD, USA.
authors.forename: Peter P
authors.initials: PP
authors.lastname: Zandi
authors.affiliation: University of Iowa Carver College of Medicine, Department of Psychiatry, Iowa City, IA, USA.
authors.forename: James B
authors.initials: JB
authors.lastname: Potash
mesh_terms: D000328:Adult; D000928:Antidepressive Agents / Q000627:therapeutic use*; D018692:Antimanic Agents / Q000627:therapeutic use*; D001714:Bipolar Disorder / Q000188:drug therapy* / Q000523:psychology; D003865:Major Depressive Disorder / Q000188:drug therapy* / Q000523:psychology; D005260:Female; D006801:Humans; D018020:Lithium Compounds / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000188:drug therapy* / Q000523:psychology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D011795:Surveys and Questionnaires / Q000592:standards; D016896:Treatment Outcome
chemical_list: D000928:Antidepressive Agents; D018692:Antimanic Agents; D018020:Lithium Compounds
keywords: Bipolar disorder; Lithium; Long-term therapy; Predictors of treatment response; Retrospective assessment; The Alda Scale