Stern said Thomas was the youngest subject of their study confirmed to have chronic traumatic encephalopathy, the same disease found in more than 20 deceased NFL players, including former Eagles safety Andre Waters, who committed suicide in 2006.
"The youngest person for whom we have seen some evidence of the disease was an 18-year-old who was a multiple-sport teen athlete who died suddenly," Stern said Tuesday in a telephone interview. "Owen is the youngest we would truly diagnose the disease - mild but definite."
Stern added, "In Owen's brain, we know there was definite involvement in the frontal cortex. The frontal lobes are the biggest parts of the brain and responsible for so many things. But one of the most important is control of behavior, including impulse control."
Thomas was the second Penn player to commit suicide in the last five years. Running back Kyle Ambrogi killed himself in 2005. Donna Ambrogi, Kyle's mother, said Tuesday that her son did not have his brain examined after his death, that the "research was just starting" at that time.
While the research team reiterated that it was not possible to establish a definite link between Thomas' suicide and his brain trauma, there is substantial evidence that CTE is a progressive disease and that he would have been affected by it later in his life.
"It is very likely that it never arrests," Stern said. "We can't say for sure."
Chris Nowinski, a former Harvard football player, is a codirector of BU's CSTE and a top activist on issues involving contact sports and head traumas. Nowinski had called Thomas' family asking for permission to study his brain.
"We need to reduce overall trauma in football, especially for kids," Nowinski said Tuesday. "We've been hitting these kids in the head 1,000 times a year and not telling them or their families the long-term consequences. We're pretty confident that the younger you are, the more damaging a concussion can be. . . . We can legitimately reinvent practice for kids to make it not about contact but about skill development."
This week, Nowinski's Sports Legacy Institute released a set of "minimum recommended guidelines for brain protection in youth sports." It calls for education programs to be established for coaches, athletes, and parents. Some youth programs are ahead of the curve, Nowinski said, mentioning a Police Athletic League program in Westport, Conn.
"I hope people choose not to ignore it," Nowinski said of this week's findings.
Contact staff writer Mike Jensen at 215-854-4489 or email@example.com.