Experts are warning against the unprescribed use of Adderall and stimulant drugs after an autopsy report showed the substances contributed to the death of a University of Tennessee student last month.

Tanner Wray, 20, collapsed during a charity boxing tournament in February. Medical responders tried to revive him, but he was later pronounced dead at UT Medical Center.

An autopsy report released this week concluded the combination of unprescribed Adderall and caffeine were a "significant condition contributing to his death."

Brandon Lock at Belew Drug usually dispenses Adderall for people with attention disorders.

"I think I see it in adults sometimes who are having trouble concentrating, remembering things, being able to focus," Lock said.