Mercedes driver determined to' keep going' in F1

Lewis Hamilton says he is determined to race in Formula 1 for as long as possible so he does not "squander" his opportunity to keep winning.

The Mercedes driver has won four of the first six races this year and is 14 victories short of Michael Schumacher's record of 91 grand prix wins.

"Michael retired when he was 38. I'm 33," said the five-time world champion.

"I can definitely do five years. I've got to keep going for as long as I can basically - until I'm not enjoying it."

Hamilton, who is actually 34 and was speaking on My Next Guest Needs No Introduction With David Letterman on Netflix, has won four of the past five World Championships.

He is leading in 2019 by 17 points from team-mate Valtteri Bottas, and said his desire for success is as strong as ever.

"I am ridiculously determined to win," said the Briton. "What really drives me, and I feel that the people I race against may lack somewhat, is that fire.

"I've got this opportunity. I could easily let go of it right now but I feel like I would be squandering it if I didn't continue to improve, grow and push."

Hamilton also said he had battled "mental issues" as a result of the demands of F1.

"It's a hard, hard year," he said. "Mentally you have these massive highs, wins and success, but then you have these massive comedowns.

"[It's] something I've never really spoken about but you often do suffer from mental issues - instabilities - and keeping yourself together when you hit rock bottom, which you do as an athlete.

"If you're lucky you can find strength at rock bottom. It's about how you get up, not how you fall."