After this age in life, everything starts to get better

This middle-age crisis is felt by people living in the US, Canada, UK and Australia, and the researchers said it was likely because people experienced higher levels of stress, worry and anger at this stage in life.

It’s the age when salaries peak, so it’s the best time to work, despite the effects it has on wellbeing, according to the researchers.

But hang on in there. The good news is that happiness is U-shaped, so the slump does get better. Worry begins to fall at the age of 50, and anger starts to fall around the age of 45 .

This chart shows that people in this age bracket were most likely to say they hadn't experienced happiness the previous day:

High-income English-speaking countries are unique in experiencing a second wind of life satisfaction; in all other parts of the world happiness continues to decline past middle age.