
Reference Monfort, Hugonot-Diener, Devouche, Wong and Péan7 Cipriani et al estimate an approximate annual incidence of 0.05% in people over the age of 60.
DIOGENES VASQUEZ FULL
Reference Halliday, Snowdon and Simpson6 The current incidence of the full syndrome is not well-known: a retrospective observational French study found 1.6 cases per 10 000 inhabitants 25% of patients had the complete syndrome and 75% had the partial syndrome.

The majority of cases occur in older adults (average age of 79 years) who live alone, although rare cases have been described in siblings and married couples. Reference Halliday, Banerjee, Philpot and Macdonald5 Reference Halliday, Banerjee, Philpot and Macdonald5 However, even in their study only 22% of individuals met all items on the scale and diagnostic criteria still lack consensus. Halliday et al in 2000 proposed domestic squalor, evidence of self-neglect, living alone, tendency to hoard and lack of concern for surroundings as the five defining features of the syndrome and they also developed the Environmental Cleanliness and Clutter Scale to assess squalor and hoarding. First cases of elderly patients with self-neglect and extreme lack of hygiene were published by Dupré in 1925 Reference Dupré2 and Stevens in 1963 Reference Stevens3 and then more precisely described as a syndrome in 1966 by Macmillan & Shaw, Reference Macmillan and Shaw4 who called this condition ‘senile breakdown’.

Diogenes syndrome – named after the Greek philosopher and cynic – is a neurobehavioural syndrome characterised by severe domestic squalor, pathological hoarding and lack of insight into the condition, Reference Assal1 the latter preventing the majority of patients from seeking medical help.
