"It very slowly and subtly reawakens addiction," Pinsky said of pain medication in an interview. "I'm not saying it was inappropriately prescribed, I'm saying he didn't know the risks."
DJ AM, whose real name was Adam Goldstein, was found dead in his apartment Friday evening. A crack pipe and prescription pills were found in the Manhattan apartment, said a law enforcement official, who spoke to The Associated Press on condition of anonymity because the investigation was ongoing.
Goldstein was 36 years old.
Pinsky is the host of VH1's "Celebrity Rehab," where he helps troubled stars get off of drugs and alcohol.
Pinsky said he believed pain medication Goldstein took for injuries sustained in the plane crash that required two skin graft surgeries reawakened his addiction to drugs. Goldstein had long preached sobriety and openly discussed his earlier addictions to drugs including crack cocaine and Ecstasy.
A medical examiner's office spokeswoman said Saturday that toxicology tests, expected to take weeks, are needed to determine what killed Goldstein. An autopsy on Sunday (NZT) was inconclusive, said the spokeswoman, Ellen Borakove.
Pinsky also expressed his grief over the loss of Goldstein. He said he considered himself a friend of the late star, and though they had not spoken for "a while," the two relayed messages to each other through friends and were "very close."
Goldstein was to debut his own show focussing on rehab in October on MTV called "Gone Too Far," featuring Goldstein staging interventions with young people battling their own addictions. MTV said it has not decided on the show's future.
In an interview with The Associated Press last month to promote the show, Goldstein said that it was terrifying watching people go through harrowing addictions and it made him recall his own battles.
"I am a recovering drug addict. When I see it and I'm in their room and the paraphernalia and the whole lifestyle and everything, I still, 11 years later, have that little thing in my head that starts thinking, 'Oh, where's that? I wonder what that is?'"
But Pinsky laughed at the notion that being close to addicts may have caused Goldstein to relapse.
"That's not in any way the kind of thing that leads to someone relapsing," he said.
Pinsky called Goldstein a model for people going through recovery and said the disc jockey was selfless when it came to helping others overcome their addictions.
"He sponsors other people, and in his words, will go to the mat supporting people on their recovery," Pinsky said.
"He was a very supportive recovery person."
Pinsky recalled how when Crazytown's Seth "Shifty" Binzer, a former patient on "Celebrity Rehab," was going through his recovery process, Pinsky urged him to reach out to DJ AM, who was a former member of the defunct band, to help learn how to stay sober.
"He was someone I referred people to to learn about recovery," said Pinsky.
Which is why he finds the circumstances of his death so shocking: "It was so much of a surprise I have a hard time believing it."
Also Saturday, Travis Barker, who was seriously injured in the South Carolina plane crash last year with Goldstein that killed four other people, expressed his sadness about his former collaborator on Twitter. The two had performed as the duo TRVSDJ-AM.
"Don't know how i am gonna play 2night but i am for AM," wrote the Blink-182 member, who is on tour with the group. "My brother is gone. i love u and miss u, i'll never forget all the good times we had."
Mandy Moore, who dated DJ AM and rushed to his side last year after he was injured in a plane crash, said in a Saturday statement that she was "absolutely heartbroken" over his sudden death.
Moore and Goldstein had a serious relationship and remained friends after it ended. She was with him last year as he recovered from burns sustained in the plane crash that killed four people.
"I am absolutely heartbroken. 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," Moore said. "To say that he will be missed beyond words is an understatement. My heart goes out to his loved ones."