Here's a quotation from "Seratonin, From Bliss to Despair," about depression:
"An automobile can be one, two or three quarts low in oil. Using the automobile as an example, imagine that brain Serotonin can have similar stages, being low (one quart low), moderately low (two quarts low), and severely low (three quarts low). The less Serotonin available in the brain, the more severe our depression and related symptoms.
When Serotonin is low, we experience problems with concentration and attention. We become scatterbrained and poorly organized. Routine responsibilities now seem overwhelming. It takes longer to do things because of poor planning. We lose our car keys and put odd things in the refrigerator. We call people and forget why we called or go to the grocery and forget what we needed. We tell people the same thing two or three times."
So, yes, expect that scatterbrained-ness to last as long as he's depressed. At the same time, however, my H used to complain that his brain was racing and he couldn't stop all the negative thoughts. I suppose it's because they're so preoccupied with their misery that depressed people become so scatterbrained about the rest of their lives.
So, though he says he's "comfortable with his life," it's not really true, it's just that depressed people have shut down so much that they can't really feel what actual happiness is like, any more.
I'm glad your D is fine! Look after your girls and yourself.