“…There is obvious uncertainty about how to define this disorder, with definitions changing over the past 30 years depending on what the current favourite theory about underlying aetiology is, and with each revision producing a higher number of potential children deemed to have the disorder (Timimi, 2002). It is hardly surprising that epidemiological studies produce hugely differing prevalence rates from 0.5% to 26% (Green, Wong, Atkins, Taylor, & Feinleib, 1999;Taylor & Hemsley, 1995) of all children.…”