Can you be too happy?
Or, what is a normal default state? Happiness and sadness both occur and are to be expected. But if a person is sad often and for long time, it might be considered a problem and treated. Part of this treatment can be anti-depressant drugs. But, are there people who are just too happy for too long? Not obsessive, not manic, not hallucinating, but just "too happy" compared to so-called normal people? Do they have some sort of pro-depressants[1] prescribed? Do they get counseling on not being so "up" and all?
I rather doubt it, but it is an interesting thought, looking at it backward from the usual. It's certainly understandable to pick the more pleasant state as the preferred default.
[1]I can't say "depressants" since depressants, as the name is used, are drugs that tend to have a calming effect. These are more anti-anxiety or tranquilizers than something to smooth off the peaks of excess happiness.