title: Association between median family income and self-reported mood symptoms in bipolar disorder.
abstract: OBJECTIVE
  There is broad consensus from epidemiologic research that lower socioeconomic status is related to poorer health. This study investigated the relation between median family income and self-reported mood symptoms in patients with bipolar disorder who reside in the United States.
  
  
  METHODS
  Two hundred eighty-four patients with bipolar disorder provided daily self-reported mood ratings for 6 months (50,054 days of data). Regardless of income, all patients were treated by a psychiatrist, took psychotropic medications, and participated in computerized self-monitoring throughout the study. Median family income was obtained from US census tract data. The association between income and mood was analyzed using income as both a continuous and categorical variable. Demographic characteristics were compared by income group. Education level was included in the analysis a priori.
  
  
  RESULTS
  Both the continuous and categorical approaches found a positive association between income and euthymia, a negative association between income and manic/hypomanic symptoms including those due to mixed states, and no association between income and depressive symptoms. Patients in the lower-income group spent 12.4% fewer days euthymic than those in the upper-income group and 9.7% fewer days euthymic than those in the middle-income group. Patients in the lower-income group spent 7.1% more days with manic/hypomanic symptoms than those in the upper-income group. There was no association between education and income.
  
  
  CONCLUSIONS
  Median family income is associated with mood symptoms in patients with bipolar disorder. Inclusion of income as a measure of socioeconomic status is recommended for future studies of outcome in bipolar disorder.
authors.affiliation: Department of Psychiatry and Psychotherapy, Universitätsklinikum Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany. michael.bauer@uniklinikum-dresden.de
authors.forename: Michael
authors.initials: M
authors.lastname: Bauer
authors.forename: Tasha
authors.initials: T
authors.lastname: Glenn
authors.forename: Natalie
authors.initials: N
authors.lastname: Rasgon
authors.forename: Wendy
authors.initials: W
authors.lastname: Marsh
authors.forename: Kemal
authors.initials: K
authors.lastname: Sagduyu
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Munoz
authors.forename: Rita
authors.initials: R
authors.lastname: Schmid
authors.forename: Sara
authors.initials: S
authors.lastname: Haack
authors.forename: Peter C
authors.initials: PC
authors.lastname: Whybrow
mesh_terms: D000328:Adult; D000339:Affect; D001714:Bipolar Disorder / Q000188:drug therapy / Q000191:economics* / Q000209:etiology / Q000523:psychology; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D007182:Income; D008297:Male; D012959:Socioeconomic Factors