How can someone be diagnosed with bipolar affective disorder without having any manic/hypomanic episode ever?(just having depressive episodes)

Bipolar disease: Diagnoses depends. Mood disorder. Check with your dr. Are you getting treatment? There are many atypical presentations.

A work in progress: Diagnoses are constantly being researched and revised. The + view is that it is self correcting and gets better - the - view is that the pharma folk use it to make $ - the truth is probably a mix and much more too. I'm old enough to still think of manic depression. Seems bipolar includes that and has more too. A link that may help: http://www.Psycheducation.Org/depression/02_diagnosis.Html.

Technically....: No. However some have proposed sub typing bipolar to include patients with depression and family histories of bipolar the initial episodes of bipolar disorder are often depression. 90% of patients will experience their first manic episode by age 50.