But the most important role of his 67-year-old life may be joining his daughter Tatum O'Neal (who won an Oscar working alongside him in 1973's Paper Moon) and his son Redmond O'Neal in a united battle against substance abuse.

The elder O'Neal was sentenced in Los Angeles Friday morning to an 18-month drug program.  The sentencing stems from a September 23, 2008, arrest of Ryan and his son, 23-year-old Redmond, on suspicion of possessing methamphetamine.

Law officials had come to the O'Neal home in Malibu to check on Redmond's probation status. Redmond's possession case will be heard on February 20.

Ryan's daughter, 45-year-old Tatum, was arrested last year in June in Manhattan on suspicion of trying to buy crack. That wake-up call, according to Tatum, caused the Oscar-winner to recommit to her own sobriety.

The arrest of her dad and brother, seeming at first to be the next chapter in an ongoing family tragedy, may hopefully turn out to be an answer to Tatum's prayers.