Are There Different Types of ADHD?

Although ADHD is referred to as a single disorder, there are different types. The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5; APA, 2013) classifies ADHD into three types:

1. Predominantly Inattentive presentation; (sometimes referred to as ADD);
2. Predominantly Hyperactive-Impulsive presentation; and,
3. Combined presentation.

Each of these types of has a distinct set of behavioral symptoms. These were discussed and reviewed in the previous several documents.  Children and adults are diagnosed using the same diagnostic set of symptoms. However, adults can have fewer symptoms and still meet the diagnostic criteria. Nevertheless, there must be evidence that the symptoms began before age 12. This is often determined using school records and historical data provided by the affected adult.

ADHD has received much greater attention in the last 20 years. This is good news because early identification and treatment lead to better outcomes. Unfortunately for most adults in the United States, this was not always the case. Some adults with ADHD were never identified during their childhood. These adults may be misdiagnosed with other mental health disorders because some symptoms such as impulsivity, excessive energy, and compulsive behavior, are common to other mental health disorders in adults. For more information about adult ADHD, please see our companion article on adult ADHD. 

How does Adult ADHD differ from Childhood ADHD?

Social scientists previously believed that ADHD was a disorder of childhood. It was thought that as a child matured into adulthood the symptoms faded away over time. A great deal of research has now been conducted examining ADHD. As more details have emerged, we now know that ADHD is a condition that affects people of all ages. In fact, the recent understanding of ADHD is a condition affecting up to 11% of children, and approximately 4% of adults (Holland, & Riley, 2014). The same ADHD symptom will look different across the lifespan. For example, hyperactivity in children evolves into an ongoing state of restlessness in adults. It is true that some children with ADHD will outgrow their symptoms. However, research indicates that at least some children are simply able to learn to manage their symptoms well enough to function successfully as adults. This healthy adaptation is the goal of most treatment, service, or educational plans.

ADHD symptoms affect the development of basic-level, cognitive skills. This in turn affects the development of more advanced-level skills. Symptoms typically increase with task complexity. Basic level skill deficits interfere with the development of new, more advanced, cognitive skills. These advanced skills include tactical skills (social engagement) and strategic skills (working to achieve long-term goals). As some individuals with ADHD mature, they can learn to master some executive functioning skills. Usually this learning is acquired later than their same-age peers. Nonetheless, they can move on to develop increasingly complex cognitive skills.

It is generally agreed that adults with ADHD may continue to experience the same types of performance limitations as they did as children. For adults, these limitations are now evident in the workplace and in marital relationships. As children, these same limitations were evident in school and in parent-child, or peer relationships. Thus, the same limitations continue over time, even as a person matures from child to adult. This can include problems with disorganization, impulsive behavior, and time management, to name just few.

To learn more about Adult ADHD, please see our companion article on adult ADHD.