There are three different types of ADHD which are commonly recognized.
1. Combined Subtype
2. Predominantly Inattentive Subtype (Also known as ADD)
3. Predominantly hyperactive & Impulsive Subtype
Attention-Deficit Disorder Without Hyperactivity
Attention deficit disorder can appear without hyperactivity, in which case the child's primary symptoms are distractibility and an inability to persist in tasks.