Depression Often Signals a Spiritual Emergency

yes, but not always.

One of the underlying commonalities in depression is black and white thinking (see above)

Are you really not aware, that this discussion about depression as a pathology vs an existential crisis with an potential for spiritual opening (not awakening, necessary; yet another important nuance) has been going on since the late 19th century (and thousands of years before that - the first chapter of the Bhagavad Gita is called "The Yoga of the Dejection of Arjuna" - if you think dejection is not the same as depression, look at his symptoms; He's completely paralyzed unable to act)

;