If there's anybody you think you can rely on when you become famous, it's your parents. Many of the rich and famous find out the hard way that their friends are only around when they have money to spend, but family is supposed to be there through thick and thin. Of all the people she thought might rip her off, her own mother was probably the person Mischa Barton suspected the least - and yet she did.
Without Barton's knowledge, her mother stole her money and took out loans against her home, all of which Barton was liable for. She then found them hard to pay after 'The O.C.' ended, and the glittering Hollywood career that everyone expected her to have failed to materialize. Her mom had basically mortgaged her future, and Barton didn't have the funds to cover it when the time came to repay the debts.