The 3 Different Types of ADHD and Their Symptoms

May 8, 2024

The 3 Different Types of ADHD and Their Symptoms

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental condition characterised by patterns of behaviour that include inattention, hyperactivity, and impulsiveness. Initially recognised predominantly in children, ADHD is now known to persist into adulthood in a significant number of cases. Symptoms often lead to challenges in academic, occupational, and social settings. The condition is diagnosed through a clinical assessment, focusing on the individual's history and symptomatology as outlined by diagnostic criteria.

ADHD presents itself in three distinct types, each with its own set of behaviours and challenges. The inattentive type is marked by difficulty in sustaining attention, following detailed instructions, and organising tasks and activities. Affected individuals may seem forgetful in daily activities and easily distracted by extraneous stimuli. On the other hand, the hyperactive-impulsive type is noted for excessive physical movement, fidgeting, an inability to sit still, impatience, and often interrupting or intruding on others’ conversations and activities. The third is the combined type of ADHD, which features a mixture of both inattentive and hyperactive-impulsive symptoms, leading to a more complex presentation.

Recognising the symptoms of the different types of ADHD is pivotal for proper diagnosis and management. While children are often the focus of concern regarding ADHD, adults can also live with undiagnosed or unmanaged symptoms. Treatment and support strategies can greatly improve outcomes for individuals with ADHD, making awareness and education important tools in addressing the challenges associated with this disorder.

Understanding ADHD

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder that affects both children and adults. It is characterised by patterns of inattention, hyperactivity, and impulsiveness that are inconsistent with developmental levels. The following subsections explain the essential aspects of ADHD, its prevalence, and the criteria used for diagnosis.

Defining ADHD

ADHD is a behavioural disorder that involves varying degrees of three main types of symptoms: inattention, hyperactivity, and impulsivity. It is generally recognised in childhood and may persist into adulthood. The disorder can have significant impacts on education, employment, and interpersonal relationships.

ADHD Prevalence

Studies suggest that ADHD is fairly common, affecting approximately 5% of children and 2.5% of adults worldwide. It is more frequently diagnosed in males than in females. Symptoms typically become evident in early childhood, often between the ages of 3 and 6.

Diagnosis Criteria

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), provides the standard criteria for ADHD diagnosis. Evaluations are comprehensive, involving clinical assessments and various psychological tests. To be diagnosed with ADHD, several symptoms must be present before the age of 12, occur in more than one setting, and not be better explained by another mental disorder:

  • Inattention: Failing to give close attention to details, difficulty sustaining attention, not appearing to listen, and being easily distracted.
  • Hyperactivity: Fidgeting, an inability to stay seated, excessive running or climbing inappropriately, difficulty with quiet activities.
  • Impulsivity: Blurting out answers, difficulty waiting for turns, and interrupting conversations or activities.

A proper evaluation also considers the severity and frequency of symptoms. Diagnosis can lead to the exploration of various treatment options, including medication, behavioural therapies, or a combination of both to manage symptoms effectively.

Types of ADHD

Attention Deficit Hyperactivity Disorder (ADHD) is classified into three main types, based on the dominant symptoms: inattentiveness, hyperactivity, and impulsivity. Identifying the type is crucial for tailoring appropriate treatments and strategies to manage symptoms effectively.

Predominantly Inattentive Type

The predominantly inattentive type of ADHD is characterised by a significant difficulty in maintaining focus, following detailed instructions, and organising tasks. Individuals may exhibit:

  • A propensity to forget daily activities
  • Easily distractible behaviour and a tendency to lose items necessary for tasks
  • Difficulty in sustaining long-term attention in work or play

Predominantly Hyperactive-Impulsive Type

The predominantly hyperactive-impulsive type displays patterns of hyperactivity and impulsivity, which are more pronounced than in the general population. Symptoms include, but are not limited to:

  • Hyperactivity: Restlessness, often fidgeting, running or climbing in inappropriate situations
  • Impulsivity: Hasty actions without forethought, interrupting or intruding on others, difficulty waiting for their turn

Combined Type ADHD

Combined Type ADHD is noted when an individual demonstrates six or more symptoms of inattention and six or more symptoms of hyperactivity-impulsivity. This type may include:

  • Inconsistent attention and hyperactive behaviours, shifting across different settings
  • Struggles with following through on instructions and sustaining attention in lengthy tasks

Symptoms and Behaviours

Attention deficit hyperactivity disorder (ADHD) is characterised by varied behaviours connected to inattention, hyperactivity, and impulsivity. Understanding the specific symptoms associated with each category can aid in identifying and managing the condition effectively.

Inattentive Symptoms

Individuals with the inattentive type of ADHD may display behaviours such as:

  • Lack of focus: Difficulty sustaining attention on tasks or play activities.
  • Forgetfulness: Often forgetting daily activities, chores, or appointments.
  • Inattention to detail: Making careless mistakes in schoolwork, at work, or during other activities.
  • Task avoidance: Avoiding or being reluctant to engage in tasks that require sustained mental effort.
  • Disorganisation: Struggling with time management and keeping materials organised.
  • Distractibility: Easily distracted by extraneous stimuli.
  • Inability to follow through: Not completing schoolwork, chores, or duties in the workplace.

Hyperactive and Impulsive Symptoms

The hyperactive-impulsive type includes behaviours such as:

  • Fidgeting and squirming: Finding it hard to sit still for extended periods.
  • Excessive physical movement: Unnecessary movement or talking in inappropriate situations.
  • Impulsivity: Acting without thinking about the consequences or making hasty decisions.
  • Interruption: Interrupting others' conversations, games, or activities.
  • Inability to wait: Difficulty waiting for their turn in line or in games.

Symptoms in Children vs Adults

While both children and adults can have ADHD, symptom expression may differ:

  • Children: Boys and girls with ADHD may often run about or climb in situations where it is inappropriate. There may be an inability to play or engage in activities quietly.
  • Adults: Adults may experience symptoms that lead to inefficiency at work, manifest as difficulties in time management, or come across as irritability and anxiety, which can also affect personal relationships. Adults typically have more subtle signs of hyperactivity but may still exhibit impulsivity and restlessness.

Impacts and Challenges

Attention Deficit Hyperactivity Disorder (ADHD) presents various impacts and challenges that can affect individuals differently depending on the type of ADHD exhibited and the severity of symptoms.

Effects on Daily Life

People with ADHD often struggle with disorganisation and a lack of attention, which can lead to issues with time management and completing tasks. Adults may have trouble maintaining a structured routine, resulting in missed appointments or deadlines. In younger individuals, this can manifest as carelessness with belongings or forgetfulness in daily activities.

Academic and Social Implications

In academic settings, students with ADHD may face challenges maintaining concentration and avoiding mistakes due to impulsiveness. Behavioural issues can also affect peer relationships, as the individual might come across as disruptive. Males with ADHD have been observed to exhibit more externalising behaviours, such as hyperactivity, while females may present more internalising behaviours, such as low self-esteem.


Behavioral Tendencies

Social Impact


Externalising (hyperactivity)



Internalising (low self-esteem)

Withdrawal from groups

Comorbid Conditions

ADHD can co-occur with several comorbid conditions that compound the difficulties an individual may face. Common comorbidities include conduct disorder, epilepsy, and bipolar disorder. These comorbid conditions can exacerbate problems with behaviour and developmental disorder progression, increasing the challenge of achieving effective treatment and management strategies.

Treatment and Management

Effective management of ADHD involves a comprehensive approach that includes medication, behavioural interventions, and supportive lifestyle changes. The individual's needs guide the selection of treatments, which are often most effective when combined.

Medication Options

Stimulants: They are the most commonly prescribed medications for ADHD. Examples include methylphenidate and dexamfetamines. These medications work by increasing dopamine levels, which help improve concentration and reduce impulsivity and hyperactivity.

  • Common side effects: include insomnia, decreased appetite, and anxiety.

Non-stimulants: Non-stimulant medications, like atomoxetine, may be used when stimulants are ineffective or cause troublesome side effects. These medications take longer to start working and can be a preferred option for some patients.

  • Potential side effects: can include nausea, fatigue, and mood swings.

Behavioural Interventions

Behaviour Therapy: Involves working with a therapist to learn skills to manage behaviour. It's particularly effective in young children with ADHD and could involve:

  • Techniques for organising tasks
  • Strategies to increase attention and decrease distractions

Behavioural Parent Training: Parents might receive training from therapists to support their child's treatment, including effective ways to respond to difficult behaviours.

Lifestyle and Support

Routine: Establishing a structured routine can provide stability and predictability for individuals with ADHD.

Exercise: Regular physical activity can help to improve overall brain function and reduce the symptoms of ADHD.

Support Groups: Individuals with ADHD and their families can benefit from participation in support groups where they can share experiences and strategies.

It's important to conduct a thorough assessment before initiating treatment and to monitor for side effects. The effectiveness of treatment options varies and may require adjustments over time.