Report: Cyclist Ty Hamilton retires

LAUSANNE, Switzerland, April 17 (UPI) -- Former Olympic cyclist Tyler Hamilton retired Friday following a positive doping test result, Cyclingnews reported.

Hamilton admitted to knowingly taking Dehydroepiandrosterone (DHEA), a banned steroid, in February.

DHEA, a natural hormone, is banned by the World Anti-Doping Agency (WADA), and its synthetic form primarily is marketed as an anti-aging drug, an anti-depressant, and for muscle growth.

He said he took the substance in an attempt to alleviate depression.

"I took a banned substance so I need to take whatever penalty they will give me and move forward," he said upon his retirement. "I woke up (Friday) knowing that I'd be talking to a few people to make it official. It really hit home and I am really sad. All careers have to come to an end."

In 2004, Hamilton began serving a two-year suspension following a positive test during a blood transfusion, and the gold medal he won at the 2004 Olympic Games at Athens, Greece, was overshadowed.