Attention Deficit Hyperactivity Disorder - Diagnosis

Diagnosis

ADHD is diagnosed via a psychiatric assessment; to rule out other potential causes or comorbidities, physical examination, radiological imaging, and laboratory tests may be used.

In North America, the DSM-IV criteria are often the basis for a diagnosis, while European countries usually use the ICD-10. If the DSM-IV criteria are used, rather than the ICD-10, a diagnosis of ADHD is 3–4 times more likely. Factors other than those within the DSM or ICD however have been found to affect the diagnosis in clinical practice. For example, children who are the youngest in a class are much more likely to be diagnosed as having ADHD compared to their older counterparts in the same year. This is because these children may behave more hyperactive not because they have ADHD but because they are younger and more developmentally behind. It is estimated that about 20 percent of children who are given a diagnosis of ADHD are misdiagnosed because of the month that they were born in.

Children who display the behavioural symptoms of ADHD but who do not have any significant functional impairments compared to their age matched peers cannot be diagnosed as having the psychiatric disorder, ADHD.

The previously used term ADD expired with the most recent revision of the DSM. As a consequence, ADHD is the current nomenclature used to describe the disorder as one distinct disorder that can manifest itself as being a primary deficit resulting in hyperactivity/impulsivity (ADHD, predominately hyperactive-impulsive type) or inattention (ADHD, predominately inattentive type) or both (ADHD combined type).