Omar Kelly of the South Florida Sun Sentinel reported on Saturday that the 27-year-old underwent "three months of treatment and therapy, psychological and neurological exams at Boston's McLean Hospital."
"For so long, I've been just trying to get help. I've been seeking help," Marshall said, per the Associated Press. "I've been talking with doctors since I've been in the NFL. No one has ever helped me. So I was praying there was a treatment out there for what I suffered from and there was."
According to the National Institute of Health, BPD is a "serious mental illness characterized by pervasive instability in moods, interpersonal relationships, self-image, and behavior."
He also talked about being vulnerable and how he will be the face of BPD.
Marshall was involved in a domestic dispute with his wife earlier this year, which resulted in him being hospitalized with stab wounds.
Michi Nogami-Marshall was arrested and charged with domestic battery, but the Dolphins receiver claimed that his wife did not stab her.
The charges were dropped on Friday.