Understanding the 3 types of ADHD

Attention deficit hyperactivity disorder (ADHD) is the name given to a neurodevelopmental disorder that causes inattention, impulsivity and hyperactivity at levels that are inappropriate for the age of the person.

Previously, three specific subtypes of ADHD were used to describe or classify this mental health disorder, but with the introduction of the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders 5) in May 2013, these ‘types’ became known as ‘presentations’.

The DSM-5 is a handbook, which healthcare professionals use, that lists the criteria for assessing and diagnosing ADHD and other mental disorders.

What are the 3 presentations of ADHD?

The two core symptom domains of ADHD are inattention and hyperactivity-impulsivity. Each of these symptom domains has 9 core symptoms, meaning that ADHD has 18 core symptoms overall.

The two core symptoms domains - inattention and hyperactivity-impulsivity - describe two of the three presentations of ADHD. The third presentation of ADHD occurs when a patient displays a combination of symptoms spread across both of the two core domains.

Presentations of ADHD	Symptoms
1. Predominantly inattentive	Often people with predominantly inattentive ADHD: Lack attention to detail or make careless mistakes Have trouble maintaining their attention on a task Don’t appear to listen Get side-tracked and lose focus. Don’t follow through on instructions Have trouble with organization Avoid or dislike tasks that require sustained mental effort Lose things Are easily distracted Are forgetful
2. Predominantly hyperactive-impulsive	Often people with predominantly hyperactive-impulsive ADHD: Squirm about or fidget with their hands or feet Have trouble remaining seated when they should Run about or climb excessively, or feel very restless Are unable to quietly partake in a leisure activity Talk excessively Are ‘on the go’ Blurt answers before a question has been completed Find it difficult to wait or take turns Interrupt or intrude on others
3. Combined	Includes symptoms of both predominantly inattentive and predominantly hyperactive-impulsive ADHD

The 3 presentations of ADHD are a part of the ADHD diagnostic criteria

ADHD can’t be diagnosed using a simple blood test or scan. A combination of clinical examinations, interviews, third party observations, behavior and symptom rating scales, and a full patient history all play a role obtaining the necessary information to make a diagnosis.

Healthcare professionals gather information and assess patients against five criteria - from A to E - to help confirm a diagnosis of ADHD.

ADHD diagnostic criteria A-E:

• A. Criterion A sets out the presentations - the domains and symptoms listed above.
  
  For a child to be diagnosed with predominantly inattentive ADHD, six or more of its nine symptoms must have been present for the past 6 months at a level that is not in keeping with what is expected for the developmental level of the child. The same applies for a diagnosis of predominantly hyperactive-impulsive ADHD.
  
  For the diagnosis of a combined presentation of ADHD to be made, the child must have had six or more symptoms in both the inattentive and hyperactive-impulsive domains for the past 6 month.
  
  For patients aged 17 years and over, only five, rather than six, symptoms need to be present.
  
  The symptoms must have a direct, negative impact on activities in a social, education or occupational setting.
  
  If the symptoms are entirely due to a failure to understand instructions, defiance, hostility or oppositional behavior, then a diagnosis of ADHD will not apply.
• B. Several symptoms must have been present before 12 years of age. Under the old diagnostic criteria, symptoms needed to be present before 7 years of age.
• C. Symptoms must be present in two or more settings, such as at home and school, at home and work, or at work and in social settings.
• D. There must be clear evidence showing that the symptoms reduce the quality of, or interfere with, functioning in social, education or work settings.
• E. The symptoms must not be better explained by another mental health disorder, or occur only during the course of a psychotic disorder, such as schizophrenia.

ADHD can also be classified as mild, moderate or severe depending on the number or intensity of the symptoms.

A diagnosis of ‘partial remission’ can also be given to patients who have previously been diagnosed with ADHD, but who have had an improvement in their symptoms and no longer meet the full diagnostic criteria. This is especially important given the symptoms of ADHD can change over time.

ADHD symptoms can change over time

The symptoms of ADHD can change over time. Adult ADHD can present differently to ADHD in children. As people age the disruptive and hyperactive behaviors seen in children with ADHD may be replaced with more subtle symptoms, such as restlessness and inattention.

Why the change from 3 ‘types’ to 3 ‘presentations’ of ADHD makes sense

The use of the word ‘presentation’ is thought to better fit with the fact that ADHD symptoms can change over time. When a person is diagnosed with a particular presentation of ADHD, it is because it best describes how their symptoms present at that point in time.

For example, a child might display predominantly hyperactive-impulsive symptoms and few inattentive ones, leading to a diagnosis of predominantly hyperactive-impulsive ADHD. As that child ages their hyperactive-impulsive symptoms may diminish and more inattentive ones may become obvious, which would result in a change of diagnosis to predominantly inattentive ADHD.

The use of the word ‘type’ was thought to suggest a more stable or fixed trait, which no longer reflects what we know about ADHD.