State, local and federal officials gathered at Boston Medical Center Monday for the formal announcement of the largest private donation in the hospital's history: $25 million to help combat addiction.

The money, donated by billionaire investor and South Shore native John Grayken and his wife, Eilene, will be used to establish the Grayken Center for Addiction Medicine at the hospital.

"Addiction is happening to all of us," Kate Walsh, the hospital's president and CEO, said during a press conference Monday. "This is the most pressing public health issue of our time."

Walsh says the money is the largest gift in the U.S. in the last decade for addiction medicine, and it will be used to coordinate research, training and treatment. She says the center will be a hub of innovation in addiction treatment and a national model.

"Our goal is to be a leader in care and prevention strategies," Walsh said. "Our aim is to end this crisis."

The Graykens were introduced to the hospital by Susan Donahue, a former board member who co-chairs its capital campaign. The couple says they prefer to donate anonymously, but are going public with hopes of destigmatizing addiction and encouraging others to do the same.

"I have personal experience with this disease and I know what it does to people," Eilene Grayken said. "It can affect anybody. It's important to me that this becomes destigmatized so people can get the proper help they need."

Gov. Charlie Baker called the Grayken's gift a "beautiful opportunity for us to do fabulous work." And Boston Mayor Marty Walsh, who is in recovery from alcoholism, says the gift will help turn around the opioid addiction crisis in the region, and do research on treatment that may help stem the tide of opioid overdose deaths.

Latest estimates suggest 2,000 people died due to an opioid overdose in Massachusetts last year.

"This gift is going to raise awareness, bring hope and save lives," Mayor Walsh said. "This will help Boston and its world-class brain power be able to have more groundbreaking research."

Boston Medical Center is at the center of an area of Boston dubbed "Methadone Mile," but Mayor Walsh prefers to call it "Recovery Road." Walsh has taken several steps to address problems in the area — such as people openly using and selling drugs. The mayor says the $25 million gift will help that effort.

"It just so happens we have a lot of addicts using drugs and alcohol here, but it's really 'Recovery Road' because they're here for a reason," Mayor Walsh said Monday. "They're not here to get drugs, because they could get drugs anywhere in the city of Boston. But they're here because they're in and out of programs. This gift is going to turn 'Recovery Road' into 'Recovery Nation.' "

Among those at Monday's announcement was Sherri Harrison, a patient at Boston Medical Center who has been drug-free for eight years.

"Addiction is a disease — not a moral failing, not a character flaw," Harrison said. "It really touches me that people are beginning to understand this and there is so much more that can be done. I agree that BMC is the place to do it."

Boston Medical Center says it will begin looking for an executive director to lead the new center and coordinate the hospital's existing services, as well as add some of the research and training components.