Bipolar disorder is complex and it can be difficult to diagnose. Hypomania is considered normal and not diagnosed, so bipolar II disorder often it is misdiagnosed as recurrent major depressive disorder. How much of major depresiv disorder is actually bipolar disorder? The concept of bipolar spectrum will help in reducing undiagnosed bipolarity. Disclose of hypomania is a important factor for the identification of bipolar II disorder.

Bipolar spectrum disorder is a continuum from pure depression to symptoms of mania along a horizontal and vertical plan.

This study aims to examinante major depression according to a new view of the bipolar spectrum and provide to answer the question: What part of major depression is in fact bipolar depression?

Were interviewed 190 patients adult with MDD, first episode or recurrent depression. Used the Hypomania Checklist-32 and Mood Disorder Questioner to identify symptoms of hypomania which will show us bipolar disorder hidden between major depresiv disorder. Patients underwent a detailed psychiatric assessment using categorical criteria of DSM-IV for bipolar disorder and dimensional criteria (tolerant criteria) of Zurich study (2005).

Interviews were taken over a one year period 2011-2012.

The tests HCL-32 and MDQ showed that about 20% (1/5) of depresive patients meet criteria for hypomania according to DSM-IV criteria. These patients are in fact bipolar disorder, treated as major depressive disorder. Refereed dimensional criteria, 24-39% (1/4-1/3) are in fact bipolar disorder.

A major part of MDD is in fact Bipolar Disorder and should be treated as such.