title: Shifts in hospital diagnostic frequencies: bipolar disorder subtypes, 1981-1993.
abstract: Annual rates of bipolar and schizoaffective disorder (SA) subtypes from 1981 to 1993 at a private university psychiatric hospital were reviewed. Annual total diagnostic rates for all bipolar disorders (BPD) remained constant between 1981 and 1993, (22%), while the frequency of SA rose 6-fold, from 1.4% to 8.7%. Rates of BPD, not otherwise specified increased 7-fold, while that for the other BPD subtypes fell in the same period of time. Several factors may have influenced these trends including changes in diagnostic criteria used, treatment-oriented diagnostic bias and indirect effects of sharply falling length of stay.
authors.affiliation: Bipolar and Psychotic Disorders Program, Mailman Research Center, McLean Hospital, Belmont MA 02178, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Zarate
authors.forename: M
authors.initials: M
authors.lastname: Tohen
authors.forename: G
authors.initials: G
authors.lastname: Baraibar
authors.forename: S B
authors.initials: SB
authors.lastname: Zarate
authors.forename: R J
authors.initials: RJ
authors.lastname: Baldessarini
mesh_terms: D001714:Bipolar Disorder / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005260:Female; D006742:Hospital Bed Capacity / Q000706:statistics & numerical data; D006778:Hospitals, Psychiatric / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D010343:Patient Admission / Q000706:statistics & numerical data*; D010359:Patient Readmission / Q000706:statistics & numerical data; D011618:Psychotic Disorders / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology*