Attention deficit hyperactivity disorder (ADHD) is a common (2.5% of adults) and highly genetic condition that adversely affects individuals across the lifespan.1 GPs will be familiar with the consequences of ADHD (for example, substance misuse, mood instability, divorce, obesity, teenage pregnancy, road traffic accidents, criminality, and underachievement). However, ADHD may be overlooked as the underlying problem, despite the potential for treatment to change lives dramatically. Many adults were not diagnosed as children despite sometimes having features of ADHD in childhood; females suffer ADHD more than previously understood, and high-functioning adults may still be severely impaired. In adults, ADHD may present more subtly: patients may concentrate during a consultation and the core features of ADHD may be hidden behind (or mistaken for) a more familiar comorbidity (for example, mood disorder). Despite the known severe impairments and negative consequences of ADHD, there may be inadequate service provision. However, this must not be misinterpreted as treatment futility; treatment is very effective both in reducing symptoms of ADHD and improving function. Box 1 lists the DSM-5 diagnostic features of ADHD.1 In adults, however, internal restlessness and an inability to ‘switch off’ are more common than visible physical hyperactivity other than fidgeting. Attention is dysregulated rather than deficient: patients can focus on topics of interest to them, often with initial enthusiasm. For example, a new hobby or subject may result in hours of internet research or participation, sometimes at the cost of time spent on other responsibilities. It may not be long before …