Critics have complained that the ADHD diagnostic criteria are sufficiently general or vague to allow virtually any child with persistent unwanted behaviors to be classified as having ADHD of one type or another. A growing number of critics have wondered why the number of children diagnosed with ADHD in the U.S. and UK has grown so dramatically over a short period of time.

It has often been suggested that the causes of the apparent ADHD epidemic lie in cultural patterns that variously encourage or sanction the use of drugs as a simple and expeditious cure for complex problems that may stem primarily from social and environmental triggers rather than any innate disorder. Some critics assert that many children are diagnosed with ADHD and put on drugs as a substitute for parental attention, whereas many parents of ADHD children assert that the associated demand for attention goes beyond what can be humanly provided, causing massive disruption to other individuals and relationships, as well as to environments with dysfunctionally structured relationships such as are manifest in many classrooms. This criticism also includes the use of prescription drugs as a substitute for parental duties such as communication and supervision.

Another source of skepticism towards making the diagnosis of "ADHD or not ADHD" may arise from the rising diagnosis of subclinical forms of ADHD. So called 'Shadow-syndromes' or 'sub-syndromes' stand for weaker forms of ADHD and are described in various degrees by John J. Ratey and Catherine Johnson on their book Shadow Syndromes: The Mild Forms of Major Mental Disorders That Sabotage Us.