Long term effectiveness and cost-effectiveness of an elimination diet trajectory compared to care as usual in the treatment of Attention Deficit/ Hyperactivity Disorder in children aged 5 to 12 year

There is growing societal discussion and concern about year by year increasing
prescription rates of medication (mostly psychostimulants) to children with
ADHD. Food seems to trigger ADHD symptoms in some children and an individually
constructed elimination diet (ED) might be an effective treatment for ADHD.

Determining the long-term (18 months) effectiveness and cost-effectiveness of
an elimination diet (ED) as the first addition to care as usual (CAU) in
comparison to providing CAU only in children with ADHD (5-12 years).
Hypotheses: Long-term treatment with ED in addition to CAU (ED-trajectory) is
superior in effectiveness to CAU and more cost-effective because fewer children
will require long-term treatment with medication. After 5 weeks ED is superior
to a control diet.

RCT with two parallel groups (and a limited comparison with a control diet)
performed in 3 child and adolescent psychiatric centers in the Netherlands,
with randomization within each participating center.

The ED trajectory consists of a 5-week elimination phase, in which children
consume a standardized diet, and a 12-18 months reintroduction phase to find
those products triggering ADHD symptoms. Non-responders to ED and children who
drop out during the reintroduction phase will switch to CAU.
Standard intervention to be compared to:
- CAU consisting of medication and / or psychosocial interventions.
- Control diet comparable to a normal dietary pattern prescribed in a very
strict and structured way, requiring the family, as in ED, to adapt the rules
and structure of the family during 5 weeks.

Burden for the ED participants are mainly related to the reintroduction phase
of the diet, which can take up to 1,5 years, in which ADHD symptoms may
re-occur after the reintroduction of a food. Burden for ED and CAU participants
consist of a 15 ml venepuncture at the start of the study, after 5 weeks of
treatment and at the end of the study. Burden for all participants and parents
are the recurrent non-invasive assessments: For children (IQ, behaviour
observation, cognitive test) the time duration per assessment varies between
1.5 and 2.5 hours (three assessments in total in 1.5 years). For parents
(parent-child observation, questionnaires) the time duration of the begin/end
point assessment (T0, T1, T4) is around 60 to 90 minutes and at other time
points (T2, T3) around 15 minutes. We believe this is feasible.
Benefits for the participants are good monitoring of treatment effectiveness
and the possibility to be treated with an elimination diet free of charge,
which is currently not yet covered by health insurance. Parents receive ¤25 per
assessment for compensation of travel expenses and time investment; children
receive a small gift (worth ¤3,-).