There is no simple “test” for ADHD. The diagnosis of ADHD is a clinical diagnosis made using well-tested diagnostic interview methods. Diagnosis is based on history, the description of symptoms, observable behaviours in at least two separate settings (school, work, and home), and the exclusion of other conditions that may resemble ADHD.
Diagnosis should include input from parents, teachers, and others who are interacting with the child or adult. The process will also consider conditions which can accompany ADHD, and the additional impacts this will have on the person. For example, depression, anxiety, trauma, learning difficulties, developmental status, oppositional defiant disorder, and conduct disorder.