Interested in reading more about this, that symptoms are more aggressive in the morning, can you refer to studies if you were thinking of some in particular?
That pattern inspired a short term treatment for MDD where sleep is limited or completely omitted. That has a very pronounced antidepressant effect in many and can even trigger mania.
Also, I have seen lots of cases among friends and family that show that behaviour.
EDIT: To clarify: This is true in a subset of patients. It is not a necessary condition.