It seems the old adage holds true: Money can't buy happiness.

At least that's according to the Better Life Index released Tuesday by the Paris-based think tank Organization for Economic Co-operation and Development. The OECD ranked the United States No. 1 in terms of household wealth and 12th in life satisfaction out of 36 countries tracked.

Denmark—which ranked 16 in household wealth—took the prize for the happiest OECD nation, while Hungary—listed at 29 in terms of income—ranked the lowest.

Americans' household wealth is about $102,000 on average, significantly higher than those in many other developed countries. Only Switzerland comes close, at about $95,000 on average.

But there's a caveat to that seemingly encouraging data point. While Americans make loads more money than many other nations, the U.S. also has one the largest gaps between the rich and poor, with the top 20 percent of the population earning nearly $82,000 a year while the bottom 20 percent get by on just $10,600.

Americans give up a lot to make all that money—workers put in long hours and take fewer vacations and less personal time, according to the Better Life Index. On average, American workers spend 1,778 hours a year in the office, higher than the OECD average, and devote less time to socializing with friends and family than workers in many other countries.

The United States scores high on housing, which measures both housing costs and housing conditions. According to the index, 20 percent of Americans' spending cash goes toward keeping a roof over their heads, slightly lower than the OECD average of 22 percent.

While Americans pay a little less when it comes to housing, they pay more than double the average in healthcare expenditures—more than $7,500 a year, with the OECD average at $3,060.

And the U.S. doesn't just outspend poorer countries. Americans spend more than twice as much as rich European countries such as France, Germany, and the United Kingdom, making the United States the biggest healthcare spender on a per-capita basis and as a share of GDP—about 17.4 percent according to the index.

While all that spending on healthcare might have translated into stellar self-reported health—90 percent of Americans say they're in good health, compared to the OECD average of 70 percent—life expectancy has actually dropped over the past several years. Americans now live an average of 79 years, a year less than the OECD average of 80 years.

Despite issues with income inequality and work-life balance, the U.S. ranks relatively well when it comes to overall life satisfaction and happiness. More than three quarters of Americans reported having more positive experiences in an average day than negatives ones, significantly higher than the 72 percent average across the countries the OECD tracks.

Still, there are plenty of countries that are happier—Denmark, Norway, Canada, and Australia—and even more countries that are more miserable.