Five-time Olympic champion Ian Thorpe believes that it is "normal" for people to contemplate taking their own lives.

The 30-year-old, who has been promoting his autobiography This Is Me, has revealed that he suffered from depression throughout his career.

"I actually think it's quite normal for people to consider what it would be like to commit suicide," Thorpe told BBC Radio Five Live. "I think it is a normal thing to think 'what would that feel like, would it be so terrible'?

"But usually that's all you think about, that's it. When you go through what the process of what it would be like and it becomes and obsession in your mind where all rational thought is devoid in that situation you realise that this has gone beyond just a thought."

Thorpe, who plans to return to the pool in time for the Rio 2016 Games, has claimed 11 world titles in his career.