A 21-year-old resident of Hubei province has not been able to sleep for three years.

Zeng said he took a job in Guangdong province that required him to work nights in 2007.

"After training myself to be awake at nights, I realized I couldn't even fall asleep during the day. So I returned home," Zeng said.

Zeng has been on medication to help him fall asleep but it has not been of much help. His weight has fallen to 44 kg.

Desperate for a cure, Zeng fed his 3-year-old brother a few sleeping pills to see if they work. The boy had to be hospitalized.

Zeng is still awake.