The "Foxcatcher" star admits his life had never been touched by drugs or the devastation drug abuse causes until he signed on to play the real-life father of an addict, portrayed by Timothee Chalamet.
The film shoot was bookended by two major family drug-related events - one vital and the other fatal.
"It was an odd confluence of events," Steve told Annette Insdorf during a recent 92nd Street Y Talks event in New York City. "I remember the week before I started shooting, my 14-year-old son, who was 12 at the time, asked me something out of the blue after I picked him up from school."
"We were driving home and we had never had one of these conversations before - he said, 'Is marijuana a gateway drug?' Obviously it was something they were talking about in school."
"I froze for a second, because here is a big conversation and I have to get this right. It was interesting that just before I was going into this movie that really dealt with a very difficult subject matter."
And then Steve was hit with the news about his niece. "We were doing a screening of the film in Boston and the next day my niece passed away from an overdose," he explains. "Up until that point I didn't have as close a connection."
"Beautiful Boy" was released in the U.S. in October and has become one of the most critically acclaimed films of the year.