Kiwi UFC superstar Mark Hunt is urging those engulfed by the darkness of depression to reach out, before it is too late.

Hunt was rocked by the sudden death of his older brother John, 44, who he said was suffering from the mental illness.

"Depression is a killer," Hunt said. "I made the mistake of never trying to reach out to my brother John but this is life. We're all going to die in the end eventually but it's a sad thing."

Sydney-based Hunt recalled visiting his brother twice last year. The first time they played darts and drank beer in South Auckland. When the 41-year-old next returned to New Zealand, though, John was a different person. He died suddenly in December.

"Depression is dangerous. He looked at me like a stranger. I felt sad for my brother," Hunt said.

The brutal mixed martial arts sensation, whose fighting potential was unearthed when a bouncer noticed his skills in a brawl outside an inner-Auckland nightclub in 1995, said John was more of an academic character growing up and had helped him embark on the road to his world-beating professional kickboxing and MMA career.

"He used to study a lot while I was running around. If it wasn't for him I wouldn't be fighting at the moment. He paid my first ticket to go over to Australia. That changed my life. I'm grateful and thankful to him for that and everything I have."

A 25-year veteran of combat sport, Hunt has experienced many highs and lows throughout a decorated career that has included the K-1 world title in 2001. He's been to dark places following disappointing losses, but says he learned the best way to come out the other side is simply to confide in others.

"It's hard because when you're suffering in silence, people can't read your mind. I learnt that from my wife, she told me to talk about it and that's what I've been doing.

"People who watch or read this, need to get help and reach out to someone."

A driving factor for him to stay positive is the love of his family, and his desire to do the best for them.

"I get depressed after I fight. That's one of those things but I'm not here for me any more I'm here for my kids and my family. That's what I look forward to doing; being a good provider for my children."

Hunt is the youngest in his family which includes one older sister and brother. He bought his parents a house before the death of his father and his mother has been recently hospitalised.

"She's powerful that women," he said. "She ain't never dying."

The dad-of-six will, in his next four fights, attempt to follow through on his quest for a heavyweight world title before retiring from the UFC. That quest continues on May 10 in Adelaide, when Hunt (10-9-1) takes on Croatian-American Stipe Miocic (12-2 ) in a potential title eliminator.

Hunt estimates his two further years in the octagon will see him fight eight more times. That number might not seem that many to some "but for a fighter like myself who's being doing it this long. You won't see me back."

* Lifeline: 0800 543 354 – Provides 24-hour telephone counselling.

* Youthline: 0800 376 633 or free text 234 – Provides 24-hour telephone and text counselling services for young people.

* Samaritans: 0800 726 666 – Provides 24-hour telephone counselling.

* Tautoko: 0508 828 865 – provides support, information and resources to people at risk of suicide, and their family, whānau and friends.

* Whatsup: 0800 942 8787 (noon to midnight).

* Kidsline: 0800 543 754 (4pm–6pm weekdays).

If it is an emergency or you feel you or someone you know is at risk, please call 111.

For information about suicide prevention, see http://www.spinz.org.nz.