Pete Davidson is in rehab after struggling with borderline personality disorder and PTSD, PageSix is reporting. Pete is being treated at the same facility in Pennsylvania where his close friend John Mulaney sought help for alcohol and drugs issues. One friend said: “Pete regularly goes to rehab for ‘tune ups’ and to take a mental break, so that’s what’s happening.” His admission comes weeks after he was forced to apologize to the head of animal charity PETA for leaving a foul-mouthed rant on her answer phone. He was also charged this month with one count of reckless driving after smashing his car into a Beverly Hills home.