The Bipolar Disorder (BD) is underdiagnosed condition worldwide. In Russia BD-II is mostly diagnosed as recurrent depressive disorder (RDD), and most cases of mania or depression with psychotic symptoms (so-called affective-delusional states) have diagnosis of schizophrenia.

To evaluate BD symptoms within the cohorts of inpatients with primary diagnoses of schizophrenia or RDD.

Patients with primary diagnosis of schizophrenia, schizoaffective disorder RDD were included. Bipolarity Index (BI) was the primary variable. Mini International Neuropsychiatric Interview (MINI) was used as a diagnostic tool. Personal and Social Performance Scale (PSP), Hypomania Checklist (HCL-32), Angst criteria for bipolarity were used for evaluation. Medical history, demographic and clinical data were analyzed.

From 741 patients included in the study, only 12% of them reached diagnostic validity for BD using only BI (score ≥60). Using MINI and clinical data the diagnosis was revised to BD in 286 patients (38.6%). BD-I was diagnosed mostly in patients with former diagnosis of acute schizophrenia, BD-II was diagnosed exclusively in patients with former diagnosis of RDD. Mean PSP score in patients with BD was significantly higher (61.5±17.4 score) than in patients with the diagnosis of psychotic syndrome (39.3±16.2) and closer to that one in patients with RDD (63.0±16.8).

In our study BI has not shown to be proper screening instrument for bipolar spectrum disorders. BD is underdiagnosed in Russia.

ClinicalTrials.gov Identifier: NCT01028196.

Supported by funding from AstraZeneca Pharmaceuticals.