Mathieu CHAPPUY1,2, Antoine BOULANGER2 , Mikail NOURREDINE1, Pierre FOURNERET3,4, Benjamin ROLLAND1,2,5,*

1. Service Universitaire d’Addictologie de Lyon (SUAL), CH Le Vinatier, Bron, France
2. Service de Psychiatrie de l’Adulte et d’Addictologie, Hôpital Edouard Herriot, Hospices Civils de Lyon, Lyon, France
3. Service Psychopathologie du Développement de l’Enfant et de l’Adolescent, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, France.
4. Univ. Lyon, UCBL, Institut des Sciences Cognitives Marc Jeannerod, UMR 5229 CNRS, Bron, France
5. Univ. Lyon, UCBL, Inserm U1028, CNRS UMR5292, CRNL, PsyR2, Bron, France

* correspondence: Postal address : Dr. Benjamin Rolland, Service Universitaire d’Addictologie, CH Le Vinatier, Pôle MOPHA, 95 Bd Pinel, F-69500 Bron, France ; telephone: +33 437 915 075; fax: +33 437 915 076; email: benjrolland@gmail.com

Keywords: ADHD ; methylphenidate ; adults ; Europe ; approval

Letter Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that typically occurs between 6 and 12 years of age and affects between 2% and 7% of school-age children [1] and between 2% and 3% of the adult population [2]. Although ADHD was initially thought to progressively disappear during adolescence, recent evidence suggests that ADHD can persist, or possibly even occur, in adulthood [3]. Methylphenidate is the most common first-line medication for treating ADHD in children. Efficacy has also been found in adults, and guidelines usually recommend the prescription of methylphenidate to adults even when the drug has not been used in childhood, provided that ADHD symptoms induce important functional impairments [4]. In the EU, while 15 countries have approved at least one form of methylphenidate for initiation in adults, individuals with ADHD who live in the remaining 14 EU countries currently have no access to a labelled treatment when it is initiated after 18 years of age (see Figure and national sources in Supplemental Document). In these latter countries, the only way to receive treatment is through off-label prescribing, which leads to several important issues for both patients and prescribers [5]. The physicians’ framework is less secured in case of off-label prescriptions, and many professionals refuse to prescribe in such cases. Consequently, patients often struggle to find a prescriber, and their medication is not always reimbursed by national or mutual health insurance systems. These circumstances expose patients to economic inequalities in their access to treatment. The European regulatory puzzle thus leads to an absurd heterogeneity in the status of methylphenidate regarding its initiation in adults with ADHD, although expert guidelines all support this practice. While misuse and diversion of methylphenidate can occasionally be met in adults, this should not exclude adult patients with ADHD from access to treatment. Moreover, off-label prescribing leads to less-supervised practices, which actually foster diversion. Consequently, homogenizing the regulatory framework of methylphenidate for adults across Europe can only strengthen patients’ safety and public health monitoring, and it would put the ethical and medical issues resulting from the current regulatory discrepancies within the EU to an end. Competing interests Pierre Fourneret and Benjamin Rolland report having received lecture fees and funds for attending congresses from HAC Pharma and Shire. The other authors report having no competing interest with the subject addressed in this letter. Acknowledgements The authors thank Maurizio Bonati, Alessandro Zuddas and Roberta Agabio (Italy), Samuel Cortese (UK), Andres Lehtmets (Estonia), and Tomislav Franic (Croatia), for their help and explanations regarding some national regulatory specificities.

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