An expatriate Briton in America was diagnosed as clinically depressed, prescribed antidepressants, and even scheduled for shock therapy, before doctors realised that he was
not depressed, just British. (Or, to be precise, English.)
Doctors described Farthing as suffering from pervasive negative anticipation: a belief that everything will turn out for the worst, whether it's trains arriving late, England's chances of winning any national sports events, or his own prospects of getting ahead in life. The doctors reported that the satisfaction he seemed to get from his pessimism was particularly pathological.
'They put me on everything -- lithium, Prozac, St. John's wort,' Farthing says. 'They even told me to sit in front of a big light for half an hour a day or I'd become suicidal. I kept telling them this was all pointless, and they said that was exactly the sort of attitude that got me here in the first place.'
The symptomology of Britishness, it seems, is indistinguishable from that of depression (the next edition of the DSM will presumably contain an entry for it). Luckily, both conditions are treatable.