Although I do know people who are clinically depressed, and the hangover/crash doesn't bother them as much, because it's their normal state anyway.
However, insofar as fun is synonymous with happiness, which is antonymous with depression, every cure for depression involves the end goal of fun - one way or another. Pharmaceutically / chemically, emotionally, socially, intellectually, spiritually, you-name-it.
Therefore, regarding this topic, I was positing that, where usage of recreational drugs as a novel cure for depression is concerned, the fun is the curative. But I can see how my generalisation could be interpreted as minimalising, if viewed as a pithy solution precluding all nuance - which it was not intended as!