I have recently returned to work after two months at home recovering from depression.
This wasn't my first meeting with 'the black dog' so I didn't need to remind myself that recovery from depression is bloody hard work. Even with modern meds and the care of qualified professionals it requires a dogged determination on the part of the patient to 'hang in there' until the 'dog' gradually releases it's hold.
Fortunately in most cases it eventually does.