Chapter 9
Figure 1 A verage number of DSM-IV ADHD symptoms (0-18) at start INCA and at end RED
LOCF = last observation carried forward
The INCA results confirm and strengthen the results of preceding randomised
controlled RED studies, all showing considerable effects of an RED on ADHD in selected as well as in unselected groups of children,1-8 with an overall effect size of 1.2 (see table 1). This effect size is impressive, taking into account that the effect size of methylphenidate (the most used drug in children with ADHD) may vary from 0.6-0.9.9,10 The effect sizes of the RED RCTs vary from 0.6-1.8, depending on the study design (see table 2). Five out of 8 studies used a double-blind placebo controlled (DBPC) design, of which in three studies a food challenge (FC) design 2,4,5 and in two studies a placebo diet was applied. 3,7 The remaining three studies used an open design,1,6,8 one of which with blinded measurements.1 Below the pros and cons of each design will be discussed.
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