SHIFTS IN-HOSPITAL DIAGNOSTIC FREQUENCIES - BIPOLAR DISORDER SUBTYPES, 1981-1993

Annual rates of bipolar and schizoaffective disorder (SA) subtypes fro m 1981 to 1993 at a private university psychiatric hospital were revie wed. Annual total diagnostic rates for all bipolar disorders (BPD) rem ained 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 s ame period of time. Several factors may have influenced these trends i ncluding changes in diagnostic criteria used, treatment-oriented diagn ostic bias and indirect effects of sharply falling length of stay. (C) 1997 Elsevier Science B.V.