In severe depression people are often face down on the bed depressed and unable to perform any tasks. They have often stopped working and some have been unable to sleep and become agitated and psychotic because of days and weeks with little and no sleep.
they often cannot attend and provide the concentration necessary for CBT.
Have you ever studied Milton Erickson of Phoenix? He sometimes solved impossible cases in record time.
Often with paradoxical intention and other cleverness.
He could often enough prescribe MORE of the worst symptom.