Did you know that there are different types of ADHD? There are three different types of ADHD! The ADHD-H (hyperactive) type is the most common in children. In adults, ADHD inattentive (ADHD I) is the most common. Do you know the difference?
I am a neurodivergent adult clinician. As someone diagnosed with ADHD and Autism late in life, I know how much misinformation exists about the different neurotypes. Unfortunately, even though I am a clinical psychologist, I have little training in the complexities of ADHD and Autism.
ADHD Subtypes: Overview
Let’s first define the three types of ADHD. There are three types of ADHD: ADHD Inattentive (ADHD I), ADHD Hyperactive and impulsive (ADHD H), and ADHD Combination type (ADHD C).
- ADHD-I is marked by difficulty regulating attention.
- ADHD-H is characterized by hyperactive and impulsive behavior
- ADHD-C is characterized by both inattention and hyperactivity/impulsivity
ADHD Inattentive (ADHD-I),
ADHD-inattentive (formally known as ADD) is characterized by the following:
- Attention is difficult to regulate
- The tendency to make mistakes
- Overlooking details, distractibility
- It isn’t easy to organize and complete tasks
- Forgetfulness
- Listening difficulties
- Ordering events or following instructions in detail can be difficult
- Difficulty performing routine tasks.
In the context of ADHD, the inattentive type can affect working memory and processing speed (processing may not be affected until the person is given too many tasks). This is the type most commonly diagnosed in adults and women.
Inattentive ADHD is not stereotypical ADHD. People tend to think of a child who struggles to sit still or is constantly running around. However, ADHD-I can look like this:
- Daydreaming in class
- Feeling anxious or depressed
- It is possible to be “spacey” and have difficulty hearing.
- Shyness
- people-pleasing
- Trouble maintaining friendships
- Picking at the cuticles and skin
- Being a perfectionist
Sluggish Cognitive Tempo is more common in people with ADHD-I. Russel Barklay described SCT, which is characterized as dreaminess, mental fogginess, slow working memory (less activity), staring often, inconsistent alertness, and excessive daydreaming. According to Fassbender and colleagues (2015), 30-63% of people with inattentive ADHD also suffer from SCT.
Inattentive ADHD is the hardest to diagnose, as it’s often misdiagnosed as “spacey” or “apathetic,” and the symptoms are mistakenly attributed to mood disorders or anxiety. As a result, they are less likely than others to be prescribed medication for ADHD, even when they have been diagnosed. Willcutt (2012) found that ADHD-I is the most common type, but people with ADHD C are more likely to receive clinical services. This suggests that people with ADHD-I might need to be more proactive and self-advocate to get the proper support and services.
ADHD Hyperactive and Impulsive (ADHD-H).
ADHD-Hyperactivity, the most common type of ADHD in preschoolers, is characterized by hyperactivity. It is often associated with early behavioral problems and high rates of Oppositional defiant disorder (ODD) or Conduct Disorder (CD). ( Bendiksen and others, 2014). ADHD-H tends to move constantly. These people often fidget and squirm in their seats or get up to stand, walk, or move around. Many people describe children with ADHD-H as “being driven by a motor.” They run around excessively. Hyperactivity can manifest as excessive talking and the inability to wait their turn. A lack of self-control could lead to impulsive behavior (such as yelling out answers or engaging in risky behaviors). This form of ADHD is more easily recognizable and therefore diagnosed faster than ADHD-I. This type of ADHD is diagnosed more often in children and men.
ADHD Combination Type (ADHD C)
ADHD-C is the most prevalent presentation in children and is very prevalent.
The combined type of ADHD is diagnosed if a person has six of nine symptoms, including both hyperactivity and inattention. ADHD-C is also associated with externalizing disorders like ODD and CD at high rates ( Bendiksen et al., 2014.). In addition, internalizing disorders such as anxiety and depression are common in people with ADHD-C.
ADHD screener: While on the subject of DSM and diagnosis, the ASRS is the most widely-used ADHD screening test, and this instrument is aligned closely with DSM criteria.
DSM-5 Criteria of the ADHD Subtypes
ADHD-I
This is how ADHD I is diagnosed using the DSM-5 criteria. In addition, six of the nine inattention symptoms must have been present over the past six months.
- Many people fail to pay close attention to detail or make careless errors in their schoolwork, workplace, or other activities.
- Has difficulty maintaining attention during tasks or games (e.g., has trouble staying focused during extended reading, lectures, or conversations).
- When spoken directly to, it often seems that the person is not listening (e.g., the mind appears elsewhere even if there are no apparent distractions).
- Follows instructions but fails to complete schoolwork, chores, or duties at work (e.g., starts tasks but loses focus quickly and is easily distracted).
- Has difficulty in organizing activities and tasks (e.g., has trouble managing sequential tasks, keeping things and materials organized, messy work, poor time management, fails to meet deadlines).
- Many people avoid, dislike, or are reluctant to engage with tasks that require sustained mental effort (e.g., schoolwork or homework; for older teens and adults, completing forms, reviewing long papers, and preparing reports).
- Loses items that are necessary to complete tasks or activities.
- Distracted by unrelated stimuli, especially in older teens and adults.
- Tends to forget daily tasks (e.g., doing chores or running errands. For older teens and adults, this could include returning calls, paying bills, or keeping appointments).
ADHD-H
Six of the nine hyperactivity symptoms must have been present in the past six months to meet the ADHD-H criteria.
- Fidgets or taps feet or hands often or squirms or fidgets in the seat.
- In situations where you are expected to remain seated, such as in a classroom, office, or workplace (or in any other situation requiring you to remain seated), people often leave their seats.
- Runs or climbs around in inappropriate situations. Note: Restlessness may only be present in adolescents or adults.
- Often unable to play or engage in leisure activities quietly.
- Tends to “move” a lot, acting like they are “driven by an engine.” (e.g., unable or unwilling to remain still for a long time in places such as restaurants or meetings. Others may perceive this as restless and difficult to keep up).
- Often talks excessively.
- Sometimes blurts out a response before the question is completed (e.g., completes other people’s sentences, cannot wait to take their turn in conversation).
- Many people have difficulty waiting for their turn, e.g., while in line.
- Interrupts or interferes with others often (e.g., interrupts conversations, games, or activities and may use other people’s items without permission. For adolescents and adults, they may take over or disrupt what others are doing).
ADHD-C
To be diagnosed with ADHD C based on DSM-5 criteria, you must have met at least six ADHD-H or six ADHD-I criteria in the past six months.
