In his final days of high school before graduation, Gaghan was expelled for driving a go-cart through the halls of the school. During the release of Traffic, a critic commented on one of the teen characters in the movie who is a drug addict and a straight-A student, calling it unrealistic, which Gaghan defended by stating that he had straight A's while he was addicted to drugs and alcohol. As Gaghan wrote in an article published in Newsweek in February 2001, "I wasn't much different from my peers, except where they could stop drinking after three or six or 10 drinks, I couldn't stop and wouldn't stop until I had progressed through marijuana, cocaine, heroin and, finally, crack and freebase--which seem for so many people to be the last stop on the elevator." Gaghan has stated that he began dealing with his addictions in 1997. "Over one long, five-day weekend, I had three separate heroin dealers get arrested," he said. "My dealer, my backup dealer and my backup-backup dealer. I was left alone, and I just hit that place, that total incomprehensible demoralization. That was the end of it; up five days straight, locked in the bathroom, convinced there was nowhere else to go, I had to kill myself, I'm going to kill myself. I just couldn't take another minute of it."