The Clinician’s Guide to ADHD combines the useful diagnostic and treatment approaches advocated in different guidelines with insights from other sources, including recent literature reviews and web resources. The aim is to provide clinicians with clear, concise, and reliable advice on how to approach this complex disorder. The guidelines referred to in compiling the book derive from authoritative sources in different regions of the world, including the United States, Canada, Australia, and Europe. After introductory discussion of epidemiology and etiology, guidance is provided on diagnosis in different age groups, differential diagnosis, assessment for potential comorbidities, and the issue of ADHD and driving. Advice is then given on the appropriate use of pharmacological and psychosocial treatment, the management of adverse events, and follow-up. A series of relevant scales, questionnaires, and websites are also included.