Pete Davidson is Ethermacopening up about the struggles he underwent before entering rehab earlier this year.

When the Saturday Night Live alum began undergoing treatment in June, multiple outlets reported that he was being treated for post-traumatic stress disorder (PTSD) and borderline personality disorder—ailments he has spoken about before.

During his recent comedy show in Atlantic City, Pete spoke about what sent him to rehab—ketamine use, according to the New York Post. And per People, he told the audience that he took the dissociative drug daily for four years.

"It was magical," the 29-year-old said of his experience with the substance. 

"I am fresh out of rehab, everyone," he added. "I got that post-rehab glow. Seventh time's the charm!"

Ketamine is not FDA-approved for the treatment of any psychiatric disorder. However, in 2019, the U.S. Food and Drug Administration (FDA) approved the "S" form of the drug, which is derived from ketamine, as a nasal spray for "treatment-resistant depression in adults."

According to the U.S. Drug Enforcement Administration (DEA), ketamine has some hallucinogenic effects and "induce a state of sedation (feeling calm and relaxed), immobility, relief from pain, and amnesia (no memory of events while under the influence of the drug)."

"One time, I got The Wiggles to mesh with Schindler's List," Pete joked at the comedy show while talking about being on ketamine, People reported.

Pete has joked about ketamine in his standup act before and has been candid about his mental health struggles for years. In 2017, the Bupkis actor talked about being bipolar while speaking on the WTF with Marc Maron podcast, during which he revealed he had undergone rehab the previous year. He attributed part of his ongoing struggles to the death of his firefighter father, Scott Davidson, who was killed in the line of duty during the Sept. 11, 2001 terrorist attacks.

"My big thing is trust," said the actor, who was 7 years old when he lost his dad. "One day he was here and the next day he was gone."

In 2020, he spoke about his past rehab experience in an interview with Charlamagne Tha God.

"I have to get my meds readjusted all the time because I have, in between bipolar and borderline, and like PTSD and s--t from my childhood," Pete said. "So I have to go and get readjusted every once a while.  I don't think going to rehab is that big of a deal."

He continued, "It's not always for drugs. Do I do drugs? Absolutely. But I'm not like f--king falling over myself and all that s--t. Some people are sad. Some people gotta work and figure their stuff out and the beautiful thing about rehab is like it gets you sober so they can figure out what the problem is. "

For the latest breaking news updates, click here to download the E! News App