Agree Noddy, it may be factors outside of the household that lead to the person down the rocky road. e.g. one sibling is being bullied at school, or elsewhere, and rest of the family don't even know about it. Likewise, it may also be factors outside of the footy club that cause a former player's personal life to derail.
Some patterns may be emerging though, and concussion is no doubt a a factor in some cases.
It would also be interesting in to know if there is a link between players caught under the illicit drug three strike policy and negative outcomes post-footy. The AFL will be quick to deflect the blame onto clubs for player outcomes, but the clubs are forced to abide by this policy that probably doesn't help anyone.