Northern Ireland is the most contented region of the UK, while London is the most anxious and least satisfied, according to statistics on local wellbeing published on Tuesday.

It will be little comfort to stressed-out, dissatisfied Londoners that their overall satisfaction has improved faster than other parts of the country.

The survey by the Office for National Statistics (ONS), which is part of the larger labour force survey with 158,000 respondents, asks people to rate out of 10 their overall satisfaction with their life, the extent to which they feel things they do are worthwhile, how happy they felt yesterday, and how anxious they felt the previous day. The national data, published in July, shows wellbeing has improved each year since 2011, but this masks regional differences.

These differences are not large, but taken together they paint a nuanced national picture. In Northern Ireland, for example, people ranked their life satisfaction at 7.85 out of 10 on average. In London this was 7.51. Londoners rated their own anxiety at 3.04 out of 10, while those in the West Midlands put it at 2.75. Those in Northern Ireland put their happiness at 7.70, while for those in the north-east it was 7.36.

The data includes almost every local authority, but sample sizes for many are very small, meaning comparing the regional picture is more reliable. The Northamptonshire town of Corby came bottom on life satisfaction and worthwhile measurements. However this was based on responses from 80 people.

The national “wellbeing index” was one of David Cameron’s flagship policies when he entered Downing Street. “It’s time we admitted that there’s more to life than money and it’s time we focused not just on GDP but on GWB – general wellbeing,” he said, and ordered the ONS to start gathering data.

Annie Quick, who leads inequality and wellbeing work at the New Economics Foundation, a thinktank that has championed the gathering of such data, said London’s gloom may be understandable. “There are real challenges about living in cities,” she said. “Commuting is very bad for wellbeing: the long periods of time spent travelling to work are ... bad for our families, and bad for community cohesion.”

The deeply unequal nature of London, where the very poor and extremely rich live within sight of one another, adds to dissatisfaction, she added.

But Northern Ireland’s apparent contentment has the experts confused – one press officer blurted out, “Really?” when the Guardian explained the ONS’s findings.

Quick said: “Northern Ireland is really interesting: if you go to Northern Ireland and talk to them, they are very surprised. We don’t have the answer.”

The local authority of Mid and East Antrim in Northern Ireland tops the table on “life satisfaction” and “worthwhile” measures and is second on the “happiness” measure. Its mayor, Audrey Wales, said she was delighted with the finding.

“Ensuring the good health and wellbeing of our citizens is a key strategic aim for Mid and East Antrim borough council and we are delighted that this survey shows that we are certainly going in the right direction.”

She added: “With a rich heritage and culture, our borough is a beautiful, welcoming and unique place with a huge offering for its citizens and visitors alike. What sets us apart is our strong community spirit and the diversity of our citizens.”

Quick said the things that affect wellbeing are well known: good-quality housing and environment, stable jobs, and functioning communities. Simply asking people how happy they feel incorporates these factors, she said, but “it’s a very sensitive measure that picks up all sorts of other things ... The challenge is for local authorities to look at those things.”

Dawn Snape, a quality of life officer at the ONS, said: “We have seen personal wellbeing improving on a UK-wide basis over the past five years. But today’s data paints a richer picture, enabling people to explore what’s been happening in their local area.

“This will help individuals, communities and local authorities to look at wellbeing locally alongside other more traditional measures of progress.”

Quick said the UK is a “world leader” at gathering these statistics. But she added: “We need to embed this thinking into devolution debates: these are often focusing on maximising economic growth but building the economy is a means to an end. What could be more important than making sure we have good quality of life?”