Attention-deficit hyperactivity disorder (ADHD) is a common neurobiological disorder that can be noticed in the preschool or early grades of school. ADHD affects between 5-12% of the population or about 1 or 2 students in every classroom.
ADHD is a medical diagnosis that is organized along two symptom clusters. They are:
Hyperactivity: difficulty regulating one’s activity level – for example constant movement in chair, getting up and down from chair, climbing, or running around when others are seated; also may manifest as talking so much that others can’t get a turn in.
Impulsivity: difficulty inhibiting behaviour – for example acting quickly without thinking.
Inattention: difficulty attending to the task at hand – for example frequent daydreaming, lost in another world or easily sidetracked by what’s going on around.
Based on these two clusters of symptoms, there are three subtypes of ADHD:
1. Predominantly hyperactive subtype
2. Predominantly inattentive subtype (sometimes called ADD)
3. Combined subtype (with both hyperactive-impulsive and inattentive symptoms)
Research has shown that school problems tend to be associated with the combined and inattentive subtypes. Students with these two subtypes tend to struggle more academically, and are more likely to fail a grade or receive lower grades than their non-ADHD classmates. By contrast, children with the predominantly Hyperactive-Impulsive subtype may do well academically, but often experience disruptive and oppositional behaviours. For children who have combined subtype both academic and behavioural problems are an issue.
ADHD Resource Centre http://www.aboutkidshealth.ca/en/resourcecentres/adhd/pages/default.aspx