For the sixth consecutive year Finland has been named the happiest nation in the world, with Denmark and Iceland a close second and third.
Ireland missed out on a place in the top 10 - coming in 14th place.
CEO of Mental Health Reform Ireland Fiona Coyle says Nordic countries are investing heavily in social services:
"It's really interesting to see those countries at the top of the index year on year. And I think that the lessons to take out of it is really in relation to investment in social services. Those Nordic countries, some of them are spending over 14% of their annual health budget on mental health and in Ireland we're around the 6% mark."
