In the individual case. But the article is making the case that in population studies, marital status can be treated as an independent variable and that children from intact parents benefit from that marriage.
So, in that sense, it "really, REALLY depends on your parents" ... It depends on whether or not they're married.
My mother was an alchoholic and ended up in a sanitarium twice, the first time when I was three years old. My smashed lumbar vertabra (which did not knit back together normally) occurred at that time and no one knows how it happened. BUT when I tried to talk to mom about it, her face expressed the look she was lying.