I found the following interesting: the happiest countries in the world take the most anti-depressants.
Top 10 Countries Ranked by Self-Reported Happiness Surveys
OECD Countries with Most Anti-Depressant Use (ranked from least to most)
Possible Explanations
1. Nothing to see here: it’s just a random correlation.
2. Anti-depressant use is correlated with something else that makes societies happy: More societal awareness and openness of mental well-being? Better healthcare systems? More trust between citizens? Wealth?
3. Anti-depressant use has a multiplier effect: If emotions are “contagious” – perhaps helping relieve the mental suffering of people who struggle with depression not only helps these people but those around them – and so on.
4. Happiness surveys are meaningless: Different cultures respond differently; scale rankings don’t tell us much about objective emotions; etc – so we should be very hesitant in using survey data to draw causation to anything.
5. High ratings of happiness increase depression: You could imagine a happiness status / inequality effect, whereby, due to social comparisons, sad people in really happy countries feel worse than sad people in moderately happy countries.
Related, Speculative Thoughts
Between now and the time the robots take over, how to mentally thrive in material abundance may end up being the major issue for most of humanity. Of course, global poverty is still a massive, massive problem, but that could end over the next couple hundred of years.
If it does, the chief concern of humanity may move from material well-being to mental well-being.
My instinct is that the science of positive psychology will continue to illuminate the foundations of meaning and happiness, but there will be genetic limits to what we can achieve.
At that point, the effectiveness of mental drugs may be the only source for increased meaning and happiness.
As such, in three hundred years, it would not shock me if there exists high levels of causation between mental drug use and happiness.