Diagnosing Bipolar Disorder and the Effect of Antidepressants: A Naturalistic Study.

Objectives: To determine if bipolar disorder isaccurately diagnosed in clinical practice and to assess theeffects of antidepressants on the course of bipolar illness.

Method: Charts of outpatients with affectivedisorder diagnoses seen in an outpatient clinic during 1 year (N= 85 with bipolar or unipolar disorders) were reviewed. Pastdiagnostic and treatment information was obtained by patientreport and systematic psychiatric history. Bipolar diagnosis wasbased on DSM-IV criteria using a SCID-based interview.

Results: Bipolar disorder was found to bemisdiagnosed as unipolar depression in 37% of patients who firstsee a mental health professional after their firstmanic/hypomanic episode. Antidepressants were used earlier andmore frequently than mood stabilizers, and 23% of this unselectedsample experienced a new or worsening rapid-cycling courseattributable to antidepressant use.

Conclusion: These results suggest that bipolardisorder tends be misdiagnosed as unipolar major depressivedisorder and that antidepressants seem to be associated with aworsened course of bipolar illness. However, this naturalistictrial was uncontrolled, and more controlled research is requiredto confirm or refute these findings.