Mandy Moore "Absolutely Devastated" By DJ AM's Death; More Celeb Reactions

Celebrity friends and business partners continue to speak out about the passing of their loved one

Hollywood is still reeling from the unexpected and tragic loss of go-to music man DJ AM, and more of Adam Goldstein's celeb pals are speaking out about his sudden death.

DJ AM's former girlfriend Mandy Moore released a statement Saturday afternoon saying that she is "absolutely heartbroken."

Remembering her ex, Moore continued: "For those of us lucky enough to have known him, Adam radiated a contagious exuberance for life and also personified the very definition of a true friend. To say that he will be missed beyond words is an understatement. My heart goes out to his loved ones." The two dated in 2007 and rekindled their romance shortly after AM's horrific plane crash late last year.

Fellow celeb DJ Samantha Ronson echoed the sentiments of many, first tweeting: "Waiting for someone to say this isn't true." Shortly after confirmation of the death, Ronson posted a picture of AM and her hugely successful DJ brother Mark Ronson, saying: "I still don't have the words- but these 2 taught me everything."

AM's close friend and addiction specialist Dr. Drew Pinsky is also speaking out about what may have caused the death of the late star...

According to a media report, Dr. Drew believes that the pain medication Goldstein took as a result of injuries sustained in his 2008 plane crash led him away from sobriety.

"It very slowly and subtly reawakens addiction," Pinsky says. "I'm not saying it was inappropriately prescribed, I'm saying he didn't know the risks."

Pinsky calls AM a "close friend" and says that he is in disbelief about the circumstances surrouding this death because of AM's influence in drug addiction recovery.

"It was so much of a surprise, I have a hard time believing it," says Dr. Drew. "He sponsors other people, and in his words, will go to the mat supporting people on their recovery."

MTV recently worked with Goldstein on his planned upcoming substance-abuse intervention show, Gone Too Far, calling DJ AM's death "an incredible loss to the music community, his friends, family and his fans, and to those of us who had the privilege of working with him." The network continued: "MTV was honored to support him as he helped young people battle their own addictions. Our heartfelt thoughts go out to his family."

Outside the Hollywood crowd, AM served as resident DJ on Friday nights at Rain Nightclub in Las Vegas hot spot the Palms Resort Casino, which held a special tribute for the "turntable phenom" last night.

Instead of their usual "AM Fridays," Rain staff honored the star by wearing his shirts and signature Nike sneakers, while the house DJ called for a moment of silence and played Diddy's version of "Every Breath I Take." The Palms also dimmed two of the four exterior lights so that only A and M were illuminated.