Actually, you'll find that if you inquire into people's lives after they win large amounts of money, many would say they're much less happy than they were before they came into the money. Their friends start demanding money, and leave if they refuse. Their spouses and loved ones start demanding money, and become estranged if they refuse. Yadda yadda yadda, so on and so on.
Whaddya expect... too many people are money-grubbing assholes.
Money can and does have a positive effect on a person's life, up to the point where you can live comfortably without financial woes. Past that point, money doesn't really add anything meaningful to a person's life, and can have negative effects. Friends, relatives, and all sorts of people feel that they're entitled to "gifts" from a person that comes into money.
Not to mention, kids who grow up in well-off families are often pretty messed up people (see Danielle Steele's daughters, Paris Hilton, etc. and so on). They merely engage in the same sort of debauchery as less well-off people, but in dramatically over-the-top ways (while wearing expensive clothing). Not always, of course, but having no limits is not good for a person's development. This also reflects on the parents, obviously.
In this story, the problem of fame that can accompany the money is also a big problem. Though it seems as though most of his problems came from the media catching him at handling his personal problems poorly, as well as incidental problems that may or may not have anything to do with the lotto jackpot.
