I wouldn't really say that Philip K. Dick relied heavily on his visions. He was a prolific writer well before he had his visions. You could say he used visions

I wouldn't really say that Philip K. Dick relied heavily on his visions. He was a prolific writer well before he had his visions. You could say he used visions as source material, but I think it is more accurate to way the he used writing to try to make sense out of his visions.