[funnym0nk3y]

It has long been known that eveningness correlates with various mental health conditions. In addition sleep is used as a marker for mental state.

Usually depression improves in the evening, sometimes very specifically at dawn. So does anxiety and OCD for some. To the point where there are little to no symptoms. In the morning however, the illness is back in full force.

There are numerous studies on the involvement of the circadian clock in depression and bipolar disorder. Many agents treating those conditions alter the circadian clock.

[pen2l]

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?

[funnym0nk3y]

Unfortunately I don't have specific studies at hand right now. However depression was classified as melancholic and atypical. Melancholic depression is marked by pronounced diurnal mood variation among other things. There was one study that measured negative and positive affect in MDD and healthy controls. It was shown that the mood variation is related to positive affect in MDD.

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.