On that theme

Adults at higher risk of suicide attempt if parent abused alcohol, research finds

As for why homes disrupted by a combination of divorce and drinking didn't lead to more risk of attempted suicides, the authors speculated that divorce may have decreased hostility at home and therefore didn't contribute to a child's becoming a maladjusted adult. "Or, it may be that children with an alcoholic parent are not as surprised when their parents split up because they have already witnessed so much conflict, so it may not lead to as much confusion and resentment as it might in a better-functioning family," Alonzo said.

Or maybe alcoholism and depression are glucose metabolism issues and divorce is not.