Facebook is to roll out features aimed at helping people who might be suffering mental ill-health.

Nearly 3 million New Zealanders are active on Facebook every month, the social network says, and many of them are sharing details of their personal lives - both the highs and the lows.

Social media often gets a bad rap when it comes to mental health, particularly that of young people.

But the way people use Facebook means it is well placed to help people when they are experiencing a low, said Facebook spokesperson Mia Garlick.

"Sometimes people are going to be using our services when they're not feeling happy and we are trying to make sure we're there for them, and giving them an appropriate experience, to help them."

Photo: Supplied/Facebook

From today, people can alert Facebook to the fact their friend appears to be suffering.

When that person next logs in, they'll be met with a host of tools, which include being able to message a friend, contact a help line, or get other tips and support. The feature has already rolled out in the US, UK and Australia.

Photo: Supplied/Facebook

"The safety and well-being of the people who use our service is tremendously important to us," said Ms Garlick, including on a pragmatic level - if people don't have a good experience, they won't keep using it.

"We're regularly looking for opportunities to really remind people how to stay safe and have a positive experience online. And also taking feedback from different groups in the LGBTIQ community, women's groups, as well as in the Māori community."

Youthline's Briana Hill said allowing people to refer their friends and family was an interesting approach.

"What I'll be interested to see is, does this facilitate people intervening in their loved ones lives - and if not, why not? What is the block stopping people doing that?"

She said if Facebook was where people were "hanging out" it was important people got a positive experience from that, and being about to say "maybe you'd like to talk to someone with some professional expertise" was great.

Ms Hill said research in 2014 found that one in two young people in New Zealand did not think their problems were big enough to ask for help.

"The message we want to give people is 'it doesn't have to be the end of the world. Or to be blunt, the end of your life.'"

Photo: Supplied/Facebook

One feature means that if a person chooses to reach out to a friend, Facebook will suggest a message they can edit and send.

"When people are in a difficult time, we've found that if we just leave a blank text box, they're less likely to complete it, because they're not quite sure how to start the words that they need to use to explain that experience."

So how long will it be before Facebook knows exactly what you're thinking when you're logged in - and how your mental health is?

Photo: Supplied/Facebook

"The challenge with technology is lack of context," Ms Garlick said.

"We can only do so much, as a platform. Other than that, we need experts and people with appropriate insights into what people are going through."

And she's quick to dispel privacy concerns, saying your boss will never see a message or data about your mental health.

"The message gets sent directly to that person, and to nobody else….I would encourage people to think before they share."

A mental health worker said other social media platforms should follow Facebook's lead.

Elliot Taylor, the manager of youth group Zeal's mental health project, said young people used more sites than just Facebook.

"It's great what Facebook is doing, but young people are doing this stuff even more on a platform like Tumblr than on Facebook, so personally I think more needs to be done to spread the net."