The comedian, 23, explains that the symptoms of the disorder are why he checked into a rehabilitation program in December 2016, initially thinking that the mental breakdowns he was experiencing were due to heavy marijuana use.
“I’ve been a pothead forever,” Davidson said on the WTF With Marc Maron podcast on Monday. “Around October [or] September last year, I started having these mental breakdowns where I would, like, freak out and then not remember what happened after. Blind rage.”
He decided to take a break from SNL and start rehab.
“I never really did any other drugs, so I was like, ‘I’m gonna try to go to rehab. Maybe that’ll be helpful,'” Davidson explained. “So I go and I get off weed. They told me there, they’re like, ‘You might be bipolar,’ and I was like, ‘OK.’ So they’re like, ‘We’re gonna try you on these meds.’ And then I got out [of rehab], and then I started smoking weed again — and I’m on meds.”
In February, he “just snapped” and had another, “really bad” mental breakdown, so he cut out marijuana completely. Davidson shared the news that he was “happy and sober for the first time in eight years” on Instagram, and explained his absence to his fans.
RELATED VIDEO: SNL’s Pete Davidson Says He’s ‘Sober for the First Time in 8 Years’: ‘I Quit Drugs and am Happy’
But three months later, Davidson was still struggling, and went back to his doctors.
“I found out I have BPD, which is borderline personality disorder,” he explained “One of my psychiatrists [diagnosed me]. He was always saying before this big meltdown, ‘You’re probably bipolar or borderline, we’re just going to have to figure it out.’ “
Davidson believes that losing his father at age 7 to the terrorist attacks at the Twin Towers on Sept. 11, 2001 had a huge impact on his mental health.
“My big thing is trust,” Davidson explained. “One day he was here and the next day he was gone.”
RELATED VIDEO: SNL’s Pete Davidson Remembers His Father Who Died on 9/11
Though he now has a diagnosis, Davidson is still figuring out how to handle the disorder, and added that he’s “depressed all the time.” He now goes to regular therapy sessions and is on a new medication.
“It is working, slowly but surely,” Davidson said. “I’ve been having a lot of problems. This whole year has been a f—— nightmare. This has been the worst year of my life, getting diagnosed with this and trying to figure out how to learn with this and live with this.”
Davidson attended the Emmys on Sept. 17 in support of SNL and his costars Kate McKinnon, Leslie Jones and Vanessa Bayer, and told PEOPLE that he is “happy and healthy.” After the show and McKinnon won, he joked that he “can’t wait to go home,” to celebrate.