Tatum O'Neal is back in rehab.

The former child star - who has a long history with drug abuse - has checked into a treatment center in Southern California in a bid to get help for her cocaine addiction. Since entering the facility, the 48-year-old actress - the youngest person ever to win an Academy Award - has been visited several times by her father Ryan O'Neal, who is desperate for his eldest child to get clean.

"Tatum recently went back to rehab last month, and she is at a facility in Orange County. Ryan has been visiting her regularly because he is so concerned about her. They are working on their complicated relationship. Tatum is just really truly struggling with who she is as a person. It's very sad to see her still suffering from her addiction to cocaine," a source said.

Tatum - who has had a complicated relationship with Ryan over the years and were, at one point, estranged - has been in out and out of rehab throughout her life as she struggled with her drug addiction.