Give information about ADHD and offer additional support to parents and carers. The support should be ADHD focused, can be group-based and as few as 1 or 2 sessions and should include education and information on the causes and impact of ADHD, advice on parenting strategies, liaison with school, college, or university (with consent). If there are also symptoms of oppositional defiant disorder or conduct disorder, offer parents and carers a parent-training programme, as well as group-based ADHD-focused support. Medication should only be offered if ADHD symptoms are still causing a persistent, significant impairment in at least one domain, after environmental modifications have been implemented and reviewed, after the individual and their parents and carers have discussed information about ADHD and after a baseline assessment has been carried out. 
A course of Cognitive Behavioural Therapy (CBT) should be considered for young people with ADHD who have benefited from medication but whose symptoms are still causing a significant impairment in at least one domain.
Medication should only be initiated by healthcare professionals with training and expertise in diagnosing and managing ADHD. For children aged 5 years and over and young people with ADHD, methylphenidate (either short or long acting) should be offered as the first line pharmacological treatment. Consider switching to lisdexamfetamine for those who have had a 6 week trial of methylphenidate, at an adequate dose, and not derived enough benefit in terms of reduced ADHD symptoms and associated impairment. Consider dexamfetamine for those whose ADHD symptoms are responding to lisdexamfetamine but who cannot tolerate the longer effect profile. Offer atomoxetine or guanfacine to those who cannot tolerate methylphenidate or lisdexamfetamine or those whose symptoms have not responded to separate 6 week trials of lisdexamfetamine and methylphenidate, having considered alternative preparations and adequate doses. Note: Methylphenidate is first-line pharmacological treatment for children aged 5 years and over and young people with ADHD. However, no formulation of methylphenidate is licensed for use in children under 6 years of age. Use in children aged 5 years (or under) is, therefore, off-label.