Clinical and Pharmacogenetic Study of Attention Deficit With Hyperactivity Disorder (ADHD)
Condition: Attention Deficit Hyperactivity Disorder
MeSH terms: Hyperkinesis; Attention Deficit Disorder with Hyperactivity
Study type: Interventional
Phase: Phase 4

Summary: 
      Attention deficit with hyperactivity disorder (ADHD) is a very common behavioral problem
      during childhood. It is estimated that up to 80% of this disorder could be related to genetic
      factors. The most common treatment for ADHD is psychostimulants. In this study, the
      researchers investigate the effect of genetic variants in increasing the risk for behaviours
      pertinent to ADHD or in modulating the response of these behaviours to methylphenidate.
      Response to methylphenidate is evaluated through a double blind placebo controlled one week
      study.
    

Detailed description: 
      Attention Deficit Hyperactivity disorder (ADHD) is a syndrome that is characterized by
      inattention, motor hyperactivity and impulsivity. It affects 8 to 12% of the population. The
      presentation of children with ADHD can be varied, from simple inattention to severe motor
      hyperactivity and impulsivity. It has a negative impact on the child's life, including poor
      school achievement and difficulty with peer and family relationships.

      Although the etiology of ADHD is not well understood, genetic factors are known to play a
      significant role in the pathogenesis of ADHD, as indicated by family, twin and adoption
      studies. In addition, environmental factors such as smoking during pregnancy and obstetrical
      complications have been found to contribute significantly in increasing the risk for and
      severity of ADHD. It is therefore likely that genetic predisposing factors interact with
      environmental factors to produce the behavioral disturbances observed in ADHD. The first goal
      of this study is therefore to investigate possible genetic and environmental risk factors,
      and examine how they might interact to confer increased risk for ADHD.

      A majority of children (70%) with ADHD show a significant improvement with of their
      behavioral disorder when treated with stimulant drugs such as methylphenidate (MPH). However,
      the extent to which each child benefits from MPH is variable and some of the children do not
      improve at all in spite of adequate trials with stimulant drugs. The second purpose of this
      project is to study the correlates/predictors of responsiveness to MPH in school-aged
      children and to identify genetic factors that may modulate the behavioral response to this
      drug.

      In order to achieve our research goals, children with ADHD are invited to participate to a
      two-week double-blind placebo controlled medication trial with MPH (Ritalin, 0.5mg/kg/day).
      During these two weeks, neuropsychological and behavioral assessments of the child are
      performed at the clinic to evaluate the cognitive performance of the child while on
      medication and placebo. Parents are invited to answer questionnaires about the behavior of
      their child and about family history of mental disorders, as well as prenatal and perinatal
      risk factors. Finally, the participating child, both parents, and siblings are invited to
      provide a blood or saliva sample for genetic analysis.
    

Intervention name(s): Ritalin; Placebo
Intervention type(s): Drug; Drug
Intervention description(s): 0.25 mg/kg bid, orally for 7 consecutive days; taken orally twice a day for 7 consecutive days
Intervention MeSH terms: Methylphenidate
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Basic Science
Keywords: Attention Deficit Hyperactivity Disorder; Genetics; Pharmacogenetics