Even without looking at data, the author should consider that his patients come to him to specifically talk about their problems, and not what is going well in their life. It gives him a skewed perspective.
https://ourworldindata.org/happiness-and-life-satisfaction
The second chart of the page shows the share of people who say they are either very happy or mostly happy, click on "Map" in the bottom right corner to see all the countries for which data is available.
Sample: US: 90 percent say they are happy China: 85 % Ethiopia: 63 %
>I have three non-mutually exclusive theories for this:
> 1. The people who come to a psychiatrist are disproportionately the unhappiest and most disturbed. This is obviously true to some degree. But I got the same sort of people when I worked in general medicine and primary care. Even the people who come to a primary care doctor are going to be a little biased towards the sorts of conditions that produce or result from sickness, but people were still much worse off than I thought.
Later on he runs a sample of twenty people to get an idea of the type of issues others around us might be facing using the statistics he provides earlier on.