"It is proposed that happiness be classified as a psychiatric disorder and be included in future editions of the major diagnostic manuals under the new name: major affective disorder, pleasant type. In a review of the relevant literature it is shown that happiness is statistically abnormal, consists of a discrete cluster of symptoms, is associated with a range of cognitive abnormalities, and probably reflects the abnormal functioning of the central nervous system. One possible objection to this proposal remains--that happiness is not negatively valued. However, this objection is dismissed as scientifically irrelevant."Okaaaay... Pretty sure this is a parody, but you never can be quite sure.
On a related note, there's also discussion about whether to classify unipolar mania. See, unipolar mania is like bipolar disorder in a higher key; instead of cycling between extremes of depression and mania, you just have the manic phases. So most of the time you're normal, except sometimes you're extremely hyper and happy.
Doesn't that sound nice?