A child must have at least six of the above symptoms.
An adolescent or adult must have at least five of the above symptoms.
The symptoms must be present for at least 6 months before diagnosis
Three or more symptoms of inattentive or hyperactive-impulsive behavior must have been present before the age of 12 years.
The severity of symptoms is also important.
Everyone forgets their keys from time to time, and many children do not like doing homework. In a person with ADHD, however, these symptoms severely affect their social, school, or work life.
The symptoms will also be inappropriate for a person’s developmental level. An example of this might be a high school student who regularly climbs on top of the classroom table.
Symptoms must also appear in multiple environments, such as school, work, home, and in social situations. There needs to be clear evidence that the symptoms interfere with the individual’s quality of life.
A doctor will also consider whether another disorder can explain these symptoms.
Is a child simply rebelling against authority?
Are their behaviors a cry for attention?
With possible cases of ADHD or ADD in children, a school psychologist may observe the child’s behavior in their classroom environment, to help make a proper diagnosis.
Other conditions with similar symptoms
The behaviors must also not be due to another disorder.