OTOH, getting that much attention for depression seems quite rare, and given that there are strong learned behavioral issues with depression that require a lot of retraining, that means high frequency intervention is needed.

Talking to a therapist 1 hour a week doesn't help you manage those waves of depression you feel 20x a day 6 other days of the week. If you are going to change any subconscious or neurological patterns, you need to intervene in those moments of symptoms.