The Babadook is a unique movie due to how it represents depression and its management. Most movies show depression as simple sadness and it's solution as a bit of time on a therapists couch or a prescription. A disease with a cure.
The Babadook, though the use of creative imagery and metaphor, shows depression as condition which is to be managed and never cured. Managed through a process of examining our moods and feelings until we can fully process them and accept them.