Biomarker Research in ADHD: the Impact of Nutrition
Condition: Attention Deficit-Hyperactivity Disorder
MeSH terms: Hyperkinesis; Attention Deficit Disorder with Hyperactivity
Study type: Interventional

Summary: 
      Attention deficit hyperactivity disorder (ADHD) is the most common childhood behavioural
      disorder, causing significant impediment to a child's development. The exact aetiology of
      ADHD is still unknown. It is a complex disorder with numerous contributing (epi)genetic and
      environmental factors. Currently, treatment predominantly consists of behavioural and
      pharmacological therapy. However, medication use is associated with several side effects and
      concerns about long-term effects and efficacy exist. Therefore, there is considerable
      interest in the development of alternative treatment options.

      Double-blind research investigating the effect of a few-foods diet (FFD) has demonstrated
      large improvements in ADHD symptoms. However, following an FFD requires great effort of both
      the child and parents. To make this treatment easier or potentially obsolete, it is important
      to understand how and in which children an FFD affects ADHD symptoms.

      The investigators hypothesise that an FFD affects brain function and behaviour, including
      ADHD symptoms, via the complex network of communication between the microbiota, gut and
      brain, i.e. the MGB axis. The aim of this study is to identify potential mechanism(s)
      underlying the impact of an FFD on ADHD symptoms and to identify biomarkers that predict the
      response to the FFD.

      100 boys with ADHD will follow the FFD for 5 weeks. After inclusion, all participants will
      start with a baseline period, during which they will maintain their regular diet. The
      baseline period ends at the end of week 2. Thereafter, participants will follow a 5-week FFD,
      preceded by a 1-week transition period. The FFD period ends at the end of week 8.

      At the end of the baseline period (i.e. at the end of week 2) and at the end of the FFD (i.e.
      at the end of week 8), fMRI scans will be made, blood and buccal saliva will be collected,
      and stool and urine will be handed in. Children will do computer tasks and parents will
      complete questionnaires to monitor ADHD and physical complaints. All samples will be analysed
      by researchers blinded to behavioural responses to the FFD. To assess the impact of the FFD
      on brain function and the MGB axis, associations between ADHD behavioural changes and changes
      in other primary and secondary study outcomes will be analysed.

      This study may lead to the identification of biomarkers that can predict the response to an
      FFD. Understanding which changes - induced by an FFD - lead to improvements in ADHD symptoms
      may provide new avenues for developing treatments. Ultimately, the findings may enable
      personalised intervention strategies based on an individuals' configuration of the MGB axis.
    


Intervention name(s): Few-foods diet
Intervention type(s): Other
Intervention description(s): The few-foods diet (FFD) is followed for 5-weeks preceded by a 1-week transition period during which the child's eating pattern will be gradually adjusted. The diet consists of rice, meat (turkey and lamb), a range of vegetables, pear, rice milk with added calcium and water, and is complemented with foods such as potatoes, fruits, corn, some sweets and wheat, which are allowed in small quantities only. Normal quantities of vegetables, rice and meat are allowed every day. If necessary the diet will be adjusted to avoid foods that the child dislikes or has cravings for. If the child does not respond to the initial FFD, i.e. no change in behaviour after the first two weeks, interim adjustments to the FFD will be made in consultation with the parents.
Other intervention name(s): Restricted Elimination Diet
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Attention Deficit Hyperactivity Disorder; ADHD; child; human; diet; few-foods diet; brain; gut; microbiota