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> I think it is safe to assume that Long Term Happiness changes the brain "permanently" in the same manner.

Good intuition, and now we have hard scientific data to support it:

https://www.amazon.com/Altered-Traits-Science-Reveals-Medita...

Please note I am using a somewhat more general meaning of the word "happiness" than usually understood.

Also, in your statement I would replace "same manner" with "similar manner, opposite direction" or something like that.

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