Australians are among the happiest people in the world, while Kiwis are just feeling average, according to a new study.

The study shows Australia, Japan and the UK are among a handful of countries with a lower than average number of years lived with depression.

New Zealand, the US, Canada and all of Western Europe are average.

War zones such as Afghanistan do worst.

Australia does well compared with other countries, says lead researcher Alize Ferrari, from the University of Queensland, whose team analysed the Global Burden of Disease survey and other international research.

She emphasises, however, that depression is a major cause of disability and leads to feelings of sadness and hopelessness that can last for months or years.

Unlike previous research, her study links depression to suicide and heart disease statistics.

"Depression is a big problem," Ferrari says.

"Although there are efforts to build awareness, there is still a lot of work that needs to be done in Australia and overseas.

"The bottom line is that depression is very important chronic disease that starts in young people and affects people for most of their adult life."

The study, published in the journal PLOS ONE, is important from a public health point of view, says Professor Nick Glozier from the University of Sydney.

The more common something is the more disabling it is, he says.

"This helps planners prioritise where money is spent."

He says, however, that the study shows shows Australia is a healthy nation overall.

"We spend a lot of time speaking about how badly Australia is doing in terms of its health. But it is actually a pretty healthy population.

"The fact that we have a peaceful society is really helpful."

In stable countries there does not seem to have been any change over the past 20 years in the proportion of people who are depressed, he says.

"We spend phenomenal amounts of money on very rare and difficult-to-treat diseases compared with the amount of health service dollar spent on the second most disabling condition in the country.

"The study confirms we need to pay attention to depression.

"It's really, really important from a public health point of view."

- AAP