Kyle Craig, a musician, athlete and high-achieving student at Vanderbilt University, was the only one who saw the train coming.
His family affectionately called him "strong, large and in charge," but in just one year, Kyle lost his social confidence and became increasingly paranoid in an almost imperceptible downward spiral that deceived nearly everyone.
In the early hours last May, Kyle -- the all-American kid -- stepped out in front of a passenger train and ended his life at the age of 21.
"Kyle was confident, not arrogant," said his father, Walter "Chip" Craig of Spring Lake. N.J., as he choked back tears. "He was bright, beautiful -- a thrill a minute, focused, happy, achieving and social."
That may have been part of his undoing.
Kyle turned to Adderall -- a drug legally prescribed for attention deficit disorder (ADHD), which helped him stay up all night to study and perform the next day. By Friday, exhausted but eager to party, he would take more, mixing it with alcohol.
He had a respectable 3.5 average, but as he watched his fraternity brothers get 3.8s and 4.0s, eyeing careers on Wall Street, Kyle thought he could do better, ignoring lifelong advice that he need only "do his best."
At first he got the blue $10 pills from friends. Then, he feigned ADHD and sought a prescription from a doctor who didn't ask too many questions. And because of confidentiality laws, his parents never knew.
"Knowing that someone else is taking them and that gives them the edge, he was willing to try it," said his mother, Andrea Craig. "If he's into something, he's in all the way -- to take it to the next level."
By junior year in 2009, when Kyle told his parents he had lost interest in the fraternity parties that used to be so much fun, they thought perhaps this personality change was a sign of maturity, but only in retrospect did they realize these were the earliest signs of a growing psychosis caused by Adderall abuse.
After his death Kyle's classmates and friends told his parents, "Everyone takes Adderall."
The Craigs make no excuses for Kyle's choices, but they believe the effects of Adderall abuse, coupled with a cluster of suicides in his hometown that year, likely created the "perfect storm" that lured him to the train tracks.
Suicide is the third leading cause of death among 15- to 24-year olds and accounts for more than 12 percent of all annual deaths in that age group, according to the Centers for Disease Control and Prevention (CDC). One-third is positive for alcohol and 1 in 5 has evidence of prescription drugs.
"The hardest part is missing him...missing him," said his mother, struggling. "He was such a bright light. There's sadness, now that we know everything we know and trace it backwards to the exit ramp. If we could have known, I wonder what a difference it would have made."
Now, the Craigs, who say they are "still raw" from the loss, want others to know the danger of Adderall, a highly addictive drug that works on the brain like cocaine or methamphetamine, and is rampant on the most competitive college campuses.
An estimated 1 in 5 students has abused Adderall, a powerful combination of four time-released amphetamines that increase the amount of dopamine and norepinephrine in the brain, according to the CDC.