Attention Deficit Hyperactivity Disorder Drugs Use Chronic Effects

Attention deficit hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders in children, affecting approximately 5% children in Europe. Methylphenidate (MPH, trade name ritalin) is the most-commonly prescribed medication for ADHD children; it is also increasingly used in ADHD adults. In 2007, the European Commission requested a referral to the Committee for Medicinal Products for Human Use (CHMP) under Article 31 of Directive 2001/83/EC, as amended, for MPH because of safety concerns. The CHMP concluded that study of the long-term effects of MPH on growth, sexual development, neurological system, psychiatric states and cardiovascular system is needed. In response to the CHMP s concerns, the ADDUCE (Attention Deficit Hyperactivity Disorder Drugs Use Chronic Effects) research team has been formed by a consortium of experts in the fields of ADHD, drug safety, neuro-psychopharmacology and cardiovascular research.

The ADDUCE project aims to investigate the long-term adverse effects of MPH on growth, neurological system, psychiatric states and cardiovascular system in children and adults.

Furthermore the ADDUCE team will develop research tools for the evaluation of adverse effects of MPH on cognition and motivation.

Inclusion criteria

ADHD-treated group:

• Clinical diagnosis of ADHD
• Aged between 5 and 17 years.
• Not previously treated with methylphenidate
• Agreement between clinician, patient and their family to commence on methylphenidate (baseline measures will be taken before first prescription of methylphenidate is issued).
• Any co-medication other than dexamfetamine or atomoxetine will be allowed.
• All psychiatric and physical illness comorbidities will be allowed

ADHD-unmedicated controls:

• Clinical diagnosis of ADHD not previously treated with medication.
• Aged between 5 and 17 years.
• Agreement between clinician, patient and their family not to treat with methylphenidate.
• Any medication other than dexamfetamine or atomoxetine will be allowed.
• All comorbidities will be allowed.

Non-ADHD controls:

• Child who does not have ADHD.
• Aged between 5 and 17 years.
• Mean total clinician rated Swanson Nolan and Pelham IV Rating scale (SNAP IV) score (ADHD items) < 1.5
• Parent rated Strengths and Difficulties Questionnaire (SDQ) Hyperactivity Score within normal range for country (e.g. < 6 for UK)
• Any current medication other than dexamfetamine or atomoxetine will be allowed.
• Must never have taken methylphenidate
• Any other mental health or physical illness diagnoses will be allowed.

Exclusion criteria

All Groups:

• Current or past treatment with dexamfetamine or atomoxetine.

Un-medicated ADHD controls:

• Previous or current treatment with methylphenidate.

Non-ADHD controls:

• Previous or current treatment with methylphenidate.
• Clinician rated SNAP score ≥ 1.5. Parent rated SDQ Hyperactivity Score in Borderline or Abnormal range.