In the United States, the Diagnostic and Statistical Manual (DSM-5; APA, 2013) is the most commonly used diagnostic manual for mental and emotional disorders. It classifies ADHD into three subtypes. Each of the subtypes listed below is determined by which symptom set is most dominant: i.e., Do most of the symptoms fall into the inattentive category of symptoms? Or, do most of the symptoms fall into the hyperactive/impulsive category? Despite a dominant type, each person will still have their own unique mix of symptoms from other symptom categories as well.
1. Predominantly Inattentive type (also called, ADD): dominant symptoms are difficulties with paying attention and remaining focused on a task
2. Predominantly Hyperactive-Impulsive type: dominant symptoms are excessive movement or restless mental activity and/or problems with rash, imprudent, sudden, or thoughtless actions.
3. Combination type: No dominant type, a fairly equal balance of both 1 and 2 above.
For more detailed information about ADHD sub-types, please review our companion article, "Are there Different Types of ADHD."