“…European guidelines suggest the use of methylphenidate for initial pharmacological treatment of ADHD (Banaschewski et al, 2006;Taylor et al, 2004), and national guidelines in the UK, Spain, Germany, the Netherlands and Italy are generally consistent with this approach (Deutsche Gesellschaft für Kinder-und Jugendpsychiatrie und Psychotherapie, 2007;Health Ministry of Spain, 2010;Landelijke Stuurgroep, 2007;NICE, 2013;SINPIA, 2002). Although pharmacological and non-pharmacological interventions may help reduce ADHD symptoms, some individuals continue to experience symptoms or functional impairment that negatively affect their own/their family's lives (Preuss et al, 2006;Ralston and Lorenzo, 2004). For example, approximately 30% of children/ adolescents with ADHD fail to respond to treatment with a single stimulant and 10% do not respond to any stimulants (Arnold, 2000;Spencer et al, 1996).…”