Is there anything I can do about my parents making bad investment decisions?

What can be done about a parent who invests their life savings aggressively in money-losing businesses and investments? Although my parents made good money when they were younger, as they've aged, they've lost more and more money with each "investment" and now they're pushing themselves to the brink of bankruptcy. I think one of them may feel "behind" in terms of becoming wealthy and accomplishing life goals, so they take bigger and bigger gambles -- in industries they know very little about -- to "hit it big," losing more and more money each time. Even if they get enough money to pay of their debts -- perhaps relying on friends and family to bail them out -- I fear they'll use much of those funds betting on another "investment" gambit instead of paying their debts (including the IRS, banks, mortgage etc.). It feels like a gambling addiction, and I know of another family with this same kind of problem.