I think this is quite an oversimplification. If it was purely neurochemical, you wouldn't find any developers (or any other profession where performance is measured) who are productive during times of depression or grief. Yet sometimes those are the most prolific periods for folks (see many NBA stars this past week after Kobe's death, or the output of artists dealing with pain).
Depression is weird and influences so much stuff. But give any mediocre dev (or any professional) a dopamine-active drug of your choice and they'll see them skyrocket. It's not a popular opinion but that's the biggest factor in anything. Sure there are IQ differences etc, but they don't matter as much.
