When prescribed by a doctor, amphetamine can be used to treat attention deficit hyperactivity disorder, and narcolepsy. Recreational use of amphetamine can cause addiction and cognitive impairments.
However, according to the Boston Globe, Welker tested positive for a combination of MDMA and amphetamine. The violation was treated as a "performance enhancement." The Globe reported that Welker appealed the suspension and lost.
On Monday Welker had just returned to practice with the Denver Broncos after suffering a concussion. According to USA Today Welker suffered three concussions in 10 months.
While playing for Tech Welker had 259 receptions for 3,019 yards. He had 21 receiving touchdowns, two rushing touchdowns, and eight punt returns for touchdowns.