English Medical Psychology Melancholia

Melancholia is the most severe nonpsychotic form of depression. Nothing
can shake the person out of feeling completely terrible. Previous pleasures
now hold no interest, and even the best news falls completely flat. The
worst hours are upon awakening in the morning because the patient has
lost the gift of sleep and wakes up early (often well before dawn) with a
churning inability to get back to sleep. The person is without appetite and
has to be cajoled or forced to maintain even minimal hydration and nutrition.
Some with melancholia are agitated; others are immobile; and still
others have alternating features of both.

That's the whole passage. How do you interpret the expression?