I guess a Buddhist point of view would be that any emotion/feeling should not be held on to. (It is best to feel and let all things pass, I think, but to consider it a disorder to "hold on" to happiness doesn't seem right...I am not well-read enough about it to know if it can in fact cause suffering)

Yes. The argument is something like at some point in the future the conditions causing the happiness will be gone (probably quite soon, happiness is fleeting) and so will the feeling. If that transition away from happiness upsets you then it will cause suffering so you shouldn't cling to it.

There's a related sutta (MN87) with some dicussion about how love, which is generally an even more pleasent feeling than happiness, causes suffering if clung to because we are all inevitably separated from our loved ones.