Diagnosing ADHD

Author: Jack Cincotta Medical Reviewer: Dr. Jennie Stanford, M.D. Last updated:

Diagnosing ADHD is a complex, thorough process. This is due to many factors, such as the different subtypes of ADHD, the varying symptoms in children versus adults, and comorbid conditions that can appear very similar to ADHD. Additionally, testing for ADHD often involves multiple exams, behavioral observations, and other methods.

While the diagnostic process can take considerable time and energy, it’s important to take all of the necessary steps to ensure an accurate diagnosis and, in turn, the most appropriate treatment plan. This ultimately helps to ensure better management of ADHD and improved overall life quality.

What is ADHD?

ADHD, which stands for attention-deficit/hyperactivity disorder, is a neurodevelopmental disorder characterized by ongoing symptoms of inattention and/or hyperactivity and impulsivity. The disorder often presents at an early age, which is typically when the most noticeable symptoms appear. [1]

There are three main types of ADHD: [2]

  • Predominantly Inattentive: This generally refers to having problems with attention, organization, and staying on task.
  • Predominantly Hyperactive-Impulsive: This refers to having issues with staying still, along with fidgeting, excessive talking, and impulsive behaviors.
  • Combined: This refers to presentations of both inattention and hyperactivity-impulsivity.

Of course, the symptoms for these ADHD types also differ by age group, particularly when comparing the symptoms of children to adults.

Signs of inattention in children include: [3]

  • Making careless mistakes in schoolwork
  • Trouble staying focused on tasks or during play
  • Difficulty following through on instructions
  • Trouble finishing homework and chores
  • Difficulty organizing
  • Avoiding things that require sustained attention
  • Losing or misplacing toys, homework, and other items
  • Easily distracted

Signs of inattention in adults include: [2]

  • Making careless mistakes at work
  • Trouble completing or finishing job projects/assignments
  • Appearing inattentive when talked to
  • Easily distracted
  • Trouble staying focused at work
  • Often late to meetings or other important events

Signs of hyperactivity-impulsivity in children include: [3]

  • Fidgeting or squirming in the seat
  • Difficulty staying seated in the classroom
  • Yelling or blurting out answers when not appropriate
  • Difficulty taking turns or sharing
  • Frequent running around or climbing
  • Excessive talking in class or at home

Signs of hyperactivity-impulsivity in adults include: [2]

  • Restlessness
  • Feel as if driven by a motor
  • Trouble waiting to talk in conversations
  • Interrupting or intruding on others

ADHD symptoms can also change as one ages. Hyperactivity and impulsivity are the most common in young children, and they generally lessen over the years, whereas inattention may become more prominent during school-age years and into adolescence and adulthood. [1]

How is ADHD Diagnosed?

ADHD is diagnosed after a series of several important steps, including an initial screening and comprehensive evaluation, which involves a diagnostic interview, additional psychological/psychiatric screenings, medical evaluation, and interviews with independent sources. These steps have to be taken by qualified medical professionals, such as a psychologist, psychiatrist, or developmental-behavioral pediatrician.

The initial screening is a relatively short interview based on the criteria for ADHD listed in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR), in which a certain number of symptoms must be met in order to qualify for a diagnosis. If the criteria are met, then a comprehensive evaluation is utilized. [4] [5]

The comprehensive evaluation involves in-depth interviews not only with the individual but also with parents, spouses, or other family members, as well as teachers. This helps to provide more information on the individual’s habits and symptoms across multiple settings while increasing the overall diagnostic accuracy. [2] [4]

This comprehensive evaluation provides in-depth information on the individual’s past and present symptoms, overall severity, and how the symptoms impact school, work, relationships, and overall functioning.

The ADHD evaluation also involves a complete bio-psycho-social assessment, including an examination of medical history and medical conditions, family history, testing for comorbid disorders, and behavior rating scales, among other items. [4]

Diagnostic Criteria for ADHD

An initial ADHD diagnosis is made using the diagnostic criteria found in the DSM-5-TR. In this handbook, a certain number of specific symptoms have to be met.

For children up to age 16 years old, six or more symptoms of inattention and/or hyperactivity-impulsivity have to be present. For individuals 17 years and older, five or more symptoms in these same categories have to be present. [5]

The diagnostic symptoms for the inattentive type of ADHD are: [5]

  • Often fails to give close attention to details or makes careless mistakes in schoolwork, at work, or with other activities.
  • Often has trouble holding attention on tasks or play activities.
  • Often does not seem to listen when spoken to directly.
  • Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (e.g., loses focus, side-tracked).
  • Often has trouble organizing tasks and activities.
  • Often avoids, dislikes, or is reluctant to do tasks that require mental effort over a long period of time (such as schoolwork or homework).
  • Often loses things necessary for tasks and activities (e.g. school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, mobile telephones).
  • Is often easily distracted.
  • Is often forgetful in daily activities.

The diagnostic symptoms for the hyperactive-impulsive type of ADHD are: [5]

  • Often has trouble holding attention on tasks or play activities.
  • Often does not seem to listen when spoken to directly.
  • Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (e.g., loses focus, side-tracked).
  • Often has trouble organizing tasks and activities.
  • Often avoids, dislikes, or is reluctant to do tasks that require mental effort over a long period of time (such as schoolwork or homework).
  • Often loses things necessary for tasks and activities (e.g. school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, mobile telephones).
  • Is often easily distracted.
  • Is often forgetful in daily activities.

(Note: these items are taken directly from the DSM-5)

These symptoms also have to occur for at least six months and be deemed inappropriate for one’s developmental level. In addition to this, several other conditions must be met, including: [5]

  • Some/most of the ADHD symptoms were present before 12 years of age
  • Several symptoms exist in two or more settings (e.g., home, school, work, with friends)
  • Symptoms clearly negatively impact school, work, and/or social functioning
  • Symptoms are not attributed more accurately to another mental disorder

ADHD Screening Tools

In addition to the diagnostic interview, a variety of other tools are used to get a better understanding of the individual’s unique characteristics, symptom profile, and overall functioning.

Firstly, this involves interviews with the individual who has ADHD and others who are highly knowledgeable about the person, such as parents, spouses, and teachers. These interviews help provide important information, such as the primary symptoms, when the symptoms started, how long the symptoms last, and the severity to which symptoms impact daily life and overall functioning. [4]

Part of the comprehensive testing for ADHD also involves screening tools to help rule out other psychiatric disorders. A detailed review is typically given to test for other psychiatric disorders, such as anxiety, depression, learning disorders, autism spectrum disorder, and more. [2]

Standardized behavior rating scales can also be used to help increase the accuracy and reliability of the ADHD diagnosis. These rating scales compare the behaviors of people with ADHD to those of individuals without the condition. They are usually given to individuals with ADHD, as well as people who regularly interact with them, such as parents, teachers, caretakers, or others, depending on the exact situation. For children, a child play session may also be used to help observe behaviors. [2] [4]

Avoiding a Differential Diagnosis

Many other mental health disorders may mimic certain ADHD symptoms, which can cause confusion. However, understanding the key differences between ADHD and other disorders with similar symptoms helps to avoid an incorrect diagnosis.

The DSM-5-TR lists several common mental disorders that share similar symptoms with ADHD and addresses how to distinguish between these. Explained below are some examples that help distinguish between different diagnoses. [5]

  • ODD: Aversion to completing tasks may be mistaken for oppositional defiant disorder (ODD), yet this can be ruled out if the aversion is due to poor attention and focus abilities rather than an outright desire to resist conforming.
  • IEP: Impulsivity may lead to a diagnosis of intermittent explosive disorder (IEP). Unlike IEP, however, ADHD doesn’t involve violent or aggressive behaviors.
  • SLD: Poor school performance resulting from inattention or trouble concentrating may be mistaken for specific learning disorder (SLD). However, SLD results from inherent impaired cognitive capacities rather than primarily a lack of attentional ability.
  • Anxiety: Inattention and restlessness may lead to the diagnosis of an anxiety disorder. However, the causes of ADHD are from excess energy and novelty seeking rather than from worry and rumination in anxiety disorders.
  • ASD: Autism spectrum disorder (ASD) shares several overlapping symptoms with ADHD, such as social challenges, inattention, and behavioral issues. However, these challenges in ADHD stem from impulsivity, poor self-control, and states of hyperactivity, whereas in ASD, they result from social disengagement, difficulty adapting to change, and lack of emotional reciprocity.

Importantly, these are just several prominent examples and not an exhaustive list of all possible mental disorders that may be confused with ADHD.

In addition, it’s important to understand that many mental disorders may also exist alongside ADHD, which is called comorbidity. In other words, individuals can have symptoms that lead to a diagnosis not only for ADHD but also one or more other mental disorders.

ADHD Diagnosis in Children vs Adults

The process of reaching an ADHD diagnosis is a bit different in children compared to adults, although there are several similarities. Understanding the similarities and differences can give a better idea of what to expect during the diagnostic process.

Firstly, children 16 years and under need to exhibit at least six symptoms of inattention and/or hyperactivity-impulsivity, compared to individuals 17 and older, who require five or more symptoms in those respective areas.

Diagnosis for both children and adults involves a variety of screenings and interviews. However, the specifics of these may be different.

For example, during the diagnostic process for a child, the professional may also interview teachers, parents, and other relevant individuals. Testing may involve behavioral observations at school or home. On the other hand, during the diagnostic process for adults, additional members interviewed are usually a spouse or partner. Moreover, there typically aren’t behavioral observations with adults.

Challenges in ADHD Diagnosis

There are several challenges in ADHD diagnosis, including overlapping symptoms with other mental disorders, reliance on subjective reports, differences in symptom presentations, as well as stigmatization and/or lack of education, particularly with adult ADHD.

Many other mental disorders share overlapping symptoms with ADHD, such as anxiety disorders, mood disorders, learning disorders, and ASD. Thus, careful consideration and detailed assessments are needed to get an accurate diagnosis of ADHD.

Also, a significant part of an ADHD diagnosis is based on interviews and questionnaires, which are potentially subjective. As a result, this may lead to errors in reports about actual behaviors and symptoms.

Another thing to consider is that symptoms may present differently depending on one’s environment (e.g., work, home, school), age, and developmental level. The latter is especially prominent when comparing ADHD in young children to adults.

Stigmatization and/or lack of education are also challenges in diagnosing ADHD, particularly with adults. More specifically, ADHD has long been thought of as predominantly a disorder that affects children. While ADHD in adults has gained greater recognition, many people are still unaware of this, including not only the general public but even healthcare professionals in some instances. This may ultimately increase the risk of misdiagnosis.

Lastly, there are some important misconceptions about ADHD diagnosis that can make this process more difficult. Certain misconceptions are that ADHD: [6]

  • Can be outgrown
  • Is a made-up or illegitimate disorder
  • Is caused by parenting issues
  • Only affects boys
  • Only affects children
  • Is over-diagnosed and over-medicated

What Happens After an ADHD Diagnosis?

After receiving an ADHD diagnosis, mental health professionals will develop an individualized treatment plan, which varies from person to person, depending on age, developmental level, symptom presentation and severity, and other factors.

Generally, ADHD treatment typically involves medication and/or therapy, as well as various support strategies.

Medication for ADHD typically involves a class of medications called stimulants, although there are also potential non-stimulant medications that may be used, especially in adult patients. These help to promote attention and concentration while potentially lowering impulsivity. [1]

Cognitive-behavioral therapy (CBT) is one of the most commonly used therapies for ADHD, plus it can be useful for comorbid disorders as well. CBT helps to address unhelpful thoughts and behaviors created by ADHD and turn these into healthier ones. [1]

Regarding support strategies, mental health professionals may implement social skills training, support groups, stress management techniques, and behavioral interventions, as well as training for parents or others affected by the individual with ADHD. [1]

References
  1. National Institute of Mental Health. (2024). Attention-Deficit/Hyperactivity Disorder. U.S. Department of Health and Human Services, National Institutes of Health. https://www.nimh.nih.gov/health/topics/attention-deficit-hyperactivity-disorder-adhd
  2. Diagnosis of ADHD in Adults. (2024). CHADD. https://chadd.org/for-adults/diagnosis-of-adhd-in-adults/
  3. NHS. (2021). Symptoms – Attention Deficit Hyperactivity Disorder (ADHD). NHS. https://www.nhs.uk/conditions/attention-deficit-hyperactivity-disorder-adhd/symptoms/
  4. The ADHD diagnostic process. (2024). CHADD. https://chadd.org/for-professionals/the-adhd-diagnostic-process/
  5. American Psychiatric Association. (2022). Attention-deficit/hyperactivity disorder. In Diagnostic and statistical manual of mental disorders (5th ed., text rev.).
  6. Myths and Misunderstandings. (2024). CHADD. https://chadd.org/about-adhd/myths-and-misunderstandings/
Author Jack Cincotta Writer

Jack Cincotta is a health and wellness writer, board-certified holistic health practitioner through AADP, and holds a Master of Science degree in Psychology.

Published: Jan 6th 2025, Last edited: Jan 29th 2025

Medical Reviewer Dr. Jennie Stanford, M.D. MD, FAAFP, DipABOM

Jennie Stanford is a dual-board certified physician in both family medicine and obesity medicine, holding an MD, FAAFP, and DipABOM. She has experience in both clinical practice and peer-quality reviews.

Content reviewed by a medical professional. Last reviewed: Jan 6th 2025
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