Depressive episodes can have various causes, ranging in severity from 'needs attention' to 'very serious'. Finding the true cause means ruling out or confirming each possibility – in other words, diagnosis.
Diagnosis is usually a complex process due to the sheer number of possible causes and related symptoms. In order to diagnose depressive episodes, we could:
Have you experienced depression?
Possible responses:→ Barely worth mentioning / don't know
→ No, definitely not
→ 1-2 past episodes that were fully resolved
→ It is a repeating but tolerable problem
→ It is a repeating and serious issue