I found this on his Wikipedia bio. Other than that web page, I had never heard that story before, or knew Griffey had family problems at a young age.
Griffey Jr. Recalls Attempted Suicide
Published: March 16, 1992
As a teen-ager, Ken Griffey Jr. seemed to have it made. He was the eldest son of a baseball star, in a well-to-do family, and talented enough to be picked first in baseball's amateur draft.
But Griffey Jr., now an All-Star outfielder with the Seattle Mariners, said growing up wasn't easy. In fact, he said, life was so bad he tried to kill himself at age 17.
Griffey recounted the incident in a recent interview with The Seattle Times, which published the story Sunday.
"It seemed like everyone was yelling at me in baseball, then I came home and everyone was yelling at me there," he recalled. "I got depressed. I got angry. I didn't want to live."
In January 1988, Griffey said, he swallowed 277 aspirin by his own count and wound up in intensive care at Providence Hospital in Mount Airy, Ohio.
Griffey said he agreed to make the story public in the hope it might dissuade others from seeing suicide as a solution.