Bipolar disorder (BD) is a prevalent and chronic devastating disorder that is associated with considerable psychosocial and economic morbidity. However, its complexity in the clinical course and manifestation of bipolar disorder is still a significant barrier to accurate differential diagnosis from unipolar depression (UD), by which it is still underdiagnosed and undertreated in clinical practice. In community studies, first onset of BD is usually in the adolescent ages, and the occurrence of UD is usually its first clinical manifestation. In addition, reliable criteria for differentiating UD from BD along with validated treatment guidelines for BD are currently not sufficient or adequate, commonly resulting in misdiagnosis and mismanagement of both clinical conditions. Therefore, the study under evaluation results from clinician practice patterns in the real world will substantially enhance the current understanding on the actual situation and unmet needs for accurate and proper diagnosis and management of bipolar depression.