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Subtypes of ADHD

There are three subtypes of ADHD. Depending on his symptoms, a child may be diagnosed with:

  • Predominantly Hyperactive/Impulsive subtype: mainly hyperactive or impulsive symptoms, few or no inattentive symptoms. This subtype is rare compared to the others.
  • Predominantly Inattentive subtype: mainly inattentive symptoms, few or no hyperactive symptoms.
  • Combined subtype: both inattentive and hyperactive symptoms.

Subtypes and school problems

Children with the Predominantly Inattentive or Combined subtypes of ADHD are more likely to have problems in school. They are more likely to fail a grade or get lower grades than their peers without ADHD.

Subtypes and behaviour problems

Children with the Predominantly Hyperactive/Impulsive or Combined subtypes of ADHD are more likely to be disruptive, defiant, or aggressive. Because their behaviour is often more noticeable, they may be diagnosed at a younger age.

Subtypes can change as children grow older

As children get older, they may show fewer hyperactive and impulsive symptoms. Therefore, people who were diagnosed with the Combined subtype of ADHD as children may become Predominantly Inattentive as teens or adults.

Peter Chaban, MA, MEd

Rosemary Tannock, PhD