Ok, I actually take it back, if it was depression the author wouldn't say they'll take time to rest - this text does look like burnout indeed.

Burnout and depression are two different things (different cause, some similar/overlaping but still distinct symptoms and different kind of treatment).

I'd phrase as 'depression is burnout of the self', or 'burnout is depression of non-self contexts' such as alternate, or specialist contexts, per project/ profession, etc. (with self simply being the default context)