Eigenmann and Haenggeli have commented¹ on a paper we recently published on food additives and hyperactivity in children.² This commentary gives a seriously misleading account of the findings of the study. Eigenmann and Haenggeli claim that “the term hyperactivity seems to be used as synonymous to ADHD”. We deliberately did not use the term ADHD as a criterion for recruitment into the study. This is a diagnostic term requiring a set of explicit criteria to be met and is of doubtful validity when applied to 3 year olds. The definition of hyperactivity we used for this study was one based on the risk of subsequent behavioural difficulties in middle childhood which we had established previously in a longitudinal study of an epidemiologically ascertained sample of 3 years olds.^3,4

The study used screens for atopy (AT) and for hyperactivity (HA) applied to a total population sample to identify cases for the following design: …