After what seemed like a successful visit to an Arizona treatment facility in June for anxiety and depression, it has become clear Heather Locklear is still struggling. She was arrested Sept. 27 on suspicion of DUI near Santa Barbara, Calif. A California Highway Patrol spokesman tells Scoop a concerned witness called 911 to say the actress was "driving erratically" in a parking lot, then exited her BMW on a nearby road and "stumbled into the traffic lane."

Alcohol was ruled out as a factor, but investigators believe Locklear was under the influence of prescription medication. (Toxicology tests aren't due for several weeks.) In June sources told PEOPLE that Locklear had been battling—and taking medication for—anxiety and depression since her 2006 split from Richie Sambora (with whom she has daughter Ava, 11).