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.

☛ Journal of medical ethics: “A proposal to classify happiness as a psychiatric disorder” by Richard P. Bentall, vol. 18, no. 2, June 1992. The complete article in available online as a PDF file. (©)

Reading only its abstract, one could see in such a proposal yet another effort by the medical community to classify everything as a psychiatric disorder or a disease: “Those crazy doctors!” However, in the case of this particular paper, it would constitute a double mistake. The first mistake would be a misconception about the author’s intentions while the second, corollary to the first one, would lie in the dismissal of the whole article. Besides, it could be argued that the negative reaction to a proposal to classify happiness as being abnormal stems from the belief (if not the will) to think happiness as being normal. An idea that is as much problematic (see Georges Canguilhem’s The Normal and the Pathological first published in French, in 1943).
The general structure of Bentall’s argument relies on a “why not?” approach : according to the criteria used in the past to classify disorder (such as schizophrenia) why not declare happiness a disorder as well? The proposal to include happiness in the DSM (Diagnostic and Statistical Manual) may seem counter intuitive (as the author himself remarks). However, what the article demonstrates is that based on the classification methods used until now, it’s at least as counter-intuitive to exclude it, if not even more irrational.
Indeed, the author insists on the fact that the exclusion of happiness from the psychiatric disorders seems to be arbitrary: a decision based on social value instead of scientific facts.

More importantly, the argument that happiness be excluded from future classifications of mental disorder merely on the grounds that it is not negatively valued carries the implication that value judgment should determine our approach to psychiatric classification. Such a suggestion is clearly inimical to the spirit of psychopathology considered as a natural science. Indeed, only a psychopathology that openly declares the relevance of values to classification could persist in excluding happiness from the psychiatric disorders. (97)

This argument alone constitute a good reason to inquiry about the classification process of every disorder: if happiness is excluded for arbitrary values, than what is stoping us to think that other behavior may have been classified as disorder based on arbitrary value as well?
In the end, it seems that the article main goal lies as much in an attempt at developing a psychiatric understanding of happiness as it lies in the examination of the way psychiatric science classifies diseases. This interpretation of Bentall’s paper seems to find some kind of confirmation in Bentall’s research interest, as stated in his Staff profile over at the Bangor University where he currently teaches:

I am interested in the problem of classification of mental illness and in the relationship between psychopathology and normal variations in human personality. This interest has led me to challenge traditional research strategies in psychopathology, which have focused on broadly defined syndromes such as ‘schizophrenia’, and to advocate research which focuses on particular classes of abnormal behavior and experience (‘symptoms’).

On top of all this, Bentall puts forward some quite amusing ideas about happiness:

• […] happy people seem to wish to force their condition on their unhappy companions and relatives (94)

• Given the apparent similarities between happiness and depression, it seems possible that endogenous happiness [as opposed to relative happiness] will be characterized by positive mood first thing in the morning, a heavy appetite, and persistent erotomania. (95)

• Consistent clinical evidence of an association between happiness, obesity and indulgence in alcoholic beverage has existed from before the time of scientific medicine (Julius Caesar, for example, is reputed to have asked for company of fat men on these grounds). Given the well-established link between both alcohol and obesity and life-threatening illness it seems reasonable to assume that happiness poses a moderate risk to life. (96)

Seven years ago, The Sunday Times ran an article about Robert P. Bentall researches in general and about his book Madness Explained in particular. It’s a good read for someone who wishes to put the 1992 paper in perspective:

In Bentall’s view, there is no clear boundary between the sick and the well. While this feels plausible for conditions such as anxiety and depression, the suggestion that psychotic experiences run through the general population on a continuum from bland normality to florid schizophrenia has always met with resistance from psychiatrists. The received view is that psychotic symptoms, such as hearing voices or believing that thoughts are being inserted into one’s brain by alien forces, are by definition beyond the realm of ordinary experience.
Not so, says Bentall. (“Review: Psychiatry: Madness Explained by Richard P Bentall” by Paul Broks, July 27, 2003)

I first spotted Robert P. Bentall’s paper on happiness via Neatorama.