Optimizing the detection of bipolar II disorder in outpatient private practice: toward a systematization of clinical diagnostic wisdom.

BACKGROUND: We review a clinical diagnostic approach to validate a redefinition of bipolar II disorder (BPII), which bypasses several conservative steps in the DSM-IV Mood Module of the Structured Clinical Interview for DSM-IV Axis I Disorders, Clinician Version (SCID-CV) to make detection of BPII more "clinician-friendly."
METHOD: 563 consecutive private outpatients presenting with a DSM-IV-diagnosed major depressive episode (MDE) were included in the analyses. We used a modified SCID-CV in a semistructured way, used a duration of hypomania > or =2 days (rather than the 4-day floor cutoff recommended), did not follow the SCID-CV's stem (mood) skip-out instruction, focused more on past history of overactive behavior rather than mood change, and assessed hypomanic features both outside and during index MDE. Validation of BPII so-defined against major depressive disorder (MDD) was undertaken in the Washington University tradition. The study was conducted from June 1999 to December 2003.
RESULTS: BPII occurred in 56.8% of patients. Compared with MDD, BPII had a significantly earlier index age and age at onset of first MDE and higher rates of atypical features, depressive recurrences, hypomanic symptoms during MDE, trait mood lability, and bipolar family history (p = .0000 for all variables).
CONCLUSIONS: Our experience suggests that when probing history for past hypomanic episodes, behavioral activation should be inquired first, thereby facilitating the patient's subsequent recall of euphoria and/or irritability during such activated periods. Information from significant others or past records is also crucial. In light of these clinical procedures, BPII emerged as more prevalent than MDD. We submit that clinicians have the distinct advantage of intimate knowledge of their patients, which, coupled with the procedures outlined herein, can maximize the yield of BPII diagnoses.