Dr. Drew Pinsky, addiction specialist, recently sat down on Today to talk about the problems associated with this disease and the upcoming second season of Celebrity Rehab with Dr. Drew. The season premieres Thursday, which somehow seems impossibly far away.

Pinsky said doing the show itself is “very stressful,” but not for the reasons you might think. The presence of cameras and the need to create a reality show might have added to the problem of overcoming addiction, but Dr. Drew says the cameras have a “positive effect” on the celebrity patients at the Pasadena Recovery Center. “It’s a hard reality,” Drew explained. “And that’s why we did this show.”

According to Pinsky, one in eight Americans will suffer or does suffer from substance addiction. An estimated sixteen million Americans currently need immediate treatment for this problem. That’s part of what Celebrity Rehab is all about - showing the public just how tough addiction can be, proving that addicts need serious treatment. According to Dr. Drew Pinsky, addiction is a “progressive illness” which needs to be stopped in its tracks.

Drew spent some time talking about a few of the patients, cast members, we’ll soon see him treating on this latest installment of Rehab. “Gary [Busey] was very resistant to being a patient,” Drew reveals, but he said that today Busey is starting to turn it all around. “He was greatly improved and greatly relieved,” Pinsky said of Busey’s treatment.

“Steven Adler was very, very ill this time around,” Drew also stated. The promos for the series depict a long-haired, slurred-voice Adler who looks like he has no idea where he is.

“I really don’t know who’s coming in,” Pinsky explained, stating that he has nothing to do with the casting for the series. But the patients who came to Pasadena weren’t at all unfamiliar faces to Drew.

“I’ve known Sean [Stewart] for a long time. He’s a great guy,” Drew said of the son of singer Rod Stewart, whom some fans might recognize from the reality series Sons of Hollywood.

In the beginning of Celebrity seasons, each cast member is going through one of the roughest times in their lives - detox. This of course creates drama and problems among the cast. “Ultimately they, they change,” Pinsky said in his interview. Because ultimately, they become clean under his guidance.

The series will premiere its second season on VH1 Thursday night at 10 pm…but don’t expect to see any old faces mixed in with the new. There’s been no hint that former cast members might make an appearance, and that includes former American Idol Jessica Sierra. Per court order, Sierra is ensconced at the center until January 2009.…but that doesn’t mean you’ll be seeing her on the second season of Rehab.

Sierra was sentenced in January 2008, with Dr. Drew Pinsky present. She was told to complete twelve months of intensive addiction treatment under Pinsky’s care. Once this is over, she will face an additional three years’ worth of probation. Should these terms be carried out, Sierra won’t go to prison. Sierra’s lawyer petitioned for her to appear on the second season of Rehab, but the request was denied.

Per orders, Jessica must stay at least 100 yards away from all cameras during her stint at Pasadena. She cannot give interviews or be seen on television in any way. The official Sierra site contains very little information about her current life or progress.