According to a new biography,  legendary Chicago Bears running back Walter Payton – revered by fans and teammates as Sweetness – was addicted to painkillers throughout and after his playing career, engaged in many extramarital affairs, fought depression and considered suicide just before his death in 1999 at the age of 45.

Jeff Pearlman’s book “Sweetness: The Enigmatic Life of Walter Payton” alleges that after the Hall of Fame athlete's career ended in 1987, Payton descended into a state of heavy self-medication. He was also a heavy user of Darvon, an opioid narcotic used to treat mild to moderate pain, which has since been pulled off the market, according to the book due out Oct. 4.

According to Sports Illustrated, Pearlman spent two and a half years on the book and interviewed almost 700 people.

Payton, who finished his career as the NFL’s all-time leading rusher (since eclipsed by Emmitt Smith) died from bile duct cancer.

In an excerpt from the book, Pearlman wrote:

“The burden of loneliness and his marriage weren't Payton's only problems. As a player he had numbed his maladies with pills and liquids, usually supplied by the Bears. Payton popped Darvon robotically during his playing days, says [his agent Bud] Holmes, 'I'd see him walk out of the locker room with jars of painkillers, and he'd eat them like they were a snack,' and also lathered his body with dimethyl sulfoxide, a topical analgesic commonly used to treat horses. Now that he was retired, the self-medicating only intensified.

Payton habitually ingested a cocktail of Tylenol and Vicodin. In a particularly embarrassing episode, in 1988, Payton visited a handful of dental offices, complaining of severe tooth pain. He received several prescriptions for morphine and hit up a handful of drugstores to have them filled. When one of the pharmacists noticed the activity, he contacted the police, who arrived at Payton's house and discussed the situation. Payton was merely issued a warning. 'Walter was pounding his body with medication,' says Holmes. 'I wish I knew how bad it was, but at the time I really didn't.'

In the mid-1990s, Payton allegedly considered killing himself.

About this episode Pearlman wrote:

“Payton wrote a friend a letter saying that [he] needed to get his life in order and was afraid of doing 'something' he'd regret. In the note Payton admitted that he regularly contemplated suicide. Thinking about 'the people I put into this f---ed-up situation,' he wrote, 'maybe it would be better if I just disappear.' Payton said he imagined picking up his gun, murdering those around him, then turning the weapon on himself.

Separately, U.S. President Barack Obama, a huge Bears fan, said he will invite the 1985 Super Bowl champion Bears to the White House. The team's trip to the White House 25 years ago was canceled after the space shuttle Challenger tragedy.

The coach of that team, Mike Ditka, told ESPN radio that it'll be a shame that Payton will be missing.

“The shame about this thing is that Walter won’t be there,” said Ditka. “That’s the shame of this thing.”

Ironically, Ditka contemplated running against Obama in the 2004 Illinois senate race.

“I’ll be happy to go. I’m excited to go, the Bears are excited to go,” said Ditka. “It’s going to be a nice deal to be recognized and have the country say, these guys were good football players — these old guys were pretty good.”