What Is ADHD?

Medically reviewed by April Justice, LICSW
Updated April 12, 2024by BetterHelp Editorial Team

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that typically arises during childhood and can persist into an individual’s adult years.

Statistics suggest that ADHD is one of the most common neurodevelopmental disorders, with an estimated prevalence of 5% among children and adolescents and 2.5% among adults worldwide.

Marked by trouble paying attention, hyperactivity, and impulsivity, the disorder can significantly impact various facets of an individual’s life. Below, we're going to cover everything about ADHD—its symptoms, causes (including the question Is ADHD genetic?), diagnosis, and treatment.

Overview of attention-deficit/hyperactivity disorder (ADHD)


Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder that can present numerous challenges, often affecting an individual’s schooling, career, relationships, and emotional and mental health. It is characterized by trouble focusing, organizational struggles, impulsivity, executive dysfunction, and hyperactivity. The symptoms of ADHD often depend on which of three different presentations the individual experiences. These subtypes are:

  • Predominantly inattentive – Characterized by trouble concentrating on tasks, organizing, and focusing during conversations. 
  • Predominantly hyperactive-impulsive – Characterized by fidgeting, behaving impulsively, and interrupting during conversations. 
  • Combined type – Characterized by both inattentive and hyperactive-impulsive symptoms. 

Comorbidities are common with ADHD. Research suggests that approximately two thirds of children living with ADHD experience another developmental or psychological disorder

Common comorbidities with ADHD include:

  • Depressive disorders
  • Anxiety disorders
  • Substance use disorder
  • Learning disorders
  • Obsessive-compulsive disorder (OCD)
  • Conduct disorder
  • Tourette’s syndrome

As a child living with ADHD gets older, certain symptoms may diminish, particularly those related to hyperactivity. However, it is thought that many ADHD symptoms continue into adulthood. Although there is no cure for ADHD, it can be successfully managed.

What causes ADHD?

While there isn’t a unified theory explaining why ADHD develops in certain individuals, several potential contributors have been identified, including genetic, social, and environmental factors. For example, ADHD scientists have found a link between maternal health and ADHD—premature birth, drug use, and high stress during pregnancy may increase the likelihood that a child develops ADHD. Also, data from the CDC shows that boys are more than two times as likely to be diagnosed with ADHD as girls. 

Some of the primary factors thought to play a role in the development of ADHD include:

  • Genetics – While the exact genes that contribute to ADHD are unknown, the disorder is thought to be passed down through blood relatives who live with it or other mental health conditions. Studies show that the heritability of ADHD is approximately 74%. 
  • Environmental factors – Prolonged exposure to a harmful or toxic environment (e.g., living in a building with lead-based paint) can increase the chances of developing ADHD. Traumatic brain injury has also been linked to the development of the disorder. 
  • Neurological variation – Several different alterations in brain structure, function, and composition have been identified in individuals with ADHD. Research suggests that variations in brain development that inhibit the production and delivery of certain chemicals are a major cause of the disorder. Brain differences in people diagnosed with ADHD can cause deficiencies in dopamine and noradrenaline, neurotransmitters that are vital for many mental processes. Individuals with ADHD have also been found to have less gray and white matter in certain areas of the brain. 

Though some have said that watching too much TV or consuming too much sugar causes ADHD, there is insufficient evidence to substantiate these claims according to the CDC.


ADHD symptoms

Particularly in children, it is often hard to distinguish between symptoms of ADHD and behavior that is neurotypical. This is partly why a diagnosis from a healthcare professional is the most reliable way to determine for sure whether ADHD is present. The Diagnostic and Statistical Manual of Mental Disorders (DSM-V) outlines the criteria that must be fulfilled for an ADHD diagnosis to be made. Under the DSM-V, an individual’s symptoms must impair their ability to properly function in school, work, or relationships. Also, symptoms must have started before age 12.

Types of ADHD

The following are the three different subtypes of ADHD listed in the DSM-V and their applicable symptoms.

Predominantly inattentive

Adolescents 16 and younger must display at least six of the following symptoms, while those 17 and older must display at least five symptoms.

  • Lack of attention to detail, often resulting in mistakes
  • Trouble remaining focused on tasks
  • Distractibility during conversations
  • Difficulty following instructions and completing projects
  • Trouble organizing time and physical space
  • Avoids or dislikes activities that required long periods of sustained concentration
  • Frequently loses or misplaces things (e.g., toys, pencils, homework)
  • Easily distracted by external stimuli or internal thoughts
  • Predominantly hyperactive-impulsive

Adolescents 16 and younger must display at least six of the following symptoms, and those 17 and older must experience at least five symptoms.

  • Consistent fidgeting
  • Trouble remaining seated in situations where this is expected
  • Running, climbing, or displaying other restless behavior in inappropriate situations
  • Trouble quietly engaging in leisure activities or play
  • Displaying frequent restlessness, with energy levels that are often elevated
  • Talking excessively
  • Trouble waiting their turn
  • Displaying intrusive behavior, including interrupting to answer a question before it’s complete

Combined type 

This subtype is utilized for people who display a mix of characteristics and symptoms from both inattentive and hyperactive/impulsive types. 

ADHD in children

Most ADHD symptoms show up during an individual’s early school-going years. Hyperactive and impulsive symptoms—including fidgeting and trouble sitting still—are often some of the first noticeable signs of the disorder. According to the American Psychiatry Association, a child with hyperactive/impulsive type ADHD may have trouble “waiting his or her turn” and struggle to “play or do leisure activities quietly” or “follow through on instructions”. 

Once the child starts school, inattentiveness may become more apparent. A child’s teacher may notice that they’re struggling to sit still or focus on tasks. For many children, school failure is the first sign of the existence of ADHD. These academic challenges can cause low self-esteem and the development of co-occurring mental health concerns, like stress and anxiety. 

In addition to taking note of hyperactivity, inattentiveness, and impulsivity in your child’s behavior, it is suggested that caretakers observe how a child interacts with others around them.

When they’re around other children, does your child:

  • Avoid lending others their toys, snacks, and games?
  • Appear unwilling or unable to wait their turn?
  • Interrupt frequently?
  • Have difficulty listening to instructions and finishing their tasks?
  • Behave impulsively?

Answering these questions can be helpful in determining whether a child is displaying symptoms of ADHD. 

ADHD in teens

ADHD symptoms in teenagers are similar to those exhibited by children. However, the increasing pressures and other changes that often accompany teenage life can present unique concerns for those who live with the disorder. Emotional dysregulation, in particular, can be exacerbated by new responsibilities and changing hormones. Given the often-mounting scholastic demands during an individual’s teen years, challenges surrounding homework, projects, and other school-related activities may also become more noticeable in an adolescent with ADHD. Comorbid conditions like anxiety, depression, or other mental health disorders may also signal the existence of ADHD in a teenager. 

ADHD in adults

ADHD symptoms can persist into adulthood, typically with similar features but different impacts than those experienced during childhood or adolescence. Symptoms of ADHD in adults may manifest in the following ways:

  • Frequently losing track of possessions
  • Conflict in relationships
  • Trouble organizing tasks or space
  • Difficulty focusing for sustained periods 
  • Starting multiple projects without finishing them

An important point to note is that, in some cases, people are first diagnosed with ADHD in adulthood. ADHD in adults can lead to career-related challenges, relationship concerns, symptoms of comorbid mental health conditions, and poor self-esteem. Individuals who are experiencing career challenges due to ADHD may be entitled to certain protections in the workplace under the Americans with Disability Act, such as alterations to their schedule and responsibilities. If you are an adult and have been experiencing the symptoms mentioned above, consider consulting a healthcare professional who can determine whether further screening is necessary.

How do professionals diagnose ADHD?

As discussed above, ADHD can be difficult to identify, as almost all young people live with certain behaviors that are symptomatic of the disorder to some degree. It can also be hard to pinpoint ADHD symptoms in adults because many of them mimic symptoms of other mental health conditions. Regardless of age, an ADHD diagnosis will usually need to be provided by a mental health professional (e.g., a child psychologist) or medical professional (e.g., a primary care provider) prior to treatment. 

When screening an individual for ADHD, the provider will typically administer a medical examination. Such a medical evaluation can help them rule out other causes or conditions. In addition to conducting a medical exam, they will likely gather information about the individual’s lifestyle, medical history, and family through a series of interviews or questionnaires. Diagnosis is typically based on the fulfillment of ADHD criteria laid out in the DSM-V. 


How is ADHD treated?

ADHD is typically managed using a combination of medication and behavioral therapy. Additionally, healthy lifestyle changes—such as eating a balanced diet, exercising regularly, and getting plenty of sleep—can help alleviate symptoms. As with many other conditions, experts suggest early intervention so that the individual learns how to manage the disorder as soon as possible. Psychotherapy, particularly cognitive behavioral therapy, can help those with the disorder develop coping mechanisms, address emotional challenges, and navigate comorbid disorders. 

For younger children, behavior therapy is often used when treating ADHD. Behavior therapy is typically administered by parents and can help children develop healthy behaviors, such as paying attention and controlling emotions. It can also help caregivers avoid poor parenting practices that may make managing symptoms of a child’s ADHD more difficult. 

Stimulant and non-stimulant medications are often prescribed to increase levels of dopamine and noradrenaline, which can help individuals manage their symptoms and adhere to their treatment plan. Studies suggest that medication may be up to 80% effective in treating ADHD symptoms. Always consult with a healthcare professional before starting or stopping any medication. For further information and resources, visit the National Resource Center on ADHD.

Managing attention-deficit/hyperactivity disorder with online therapy

A growing number of studies point to online therapy as an effective form of treatment for ADHD. For example, in a recent meta-analysis of six studies, researchers found that online therapy improved participants' focus and social function. The study also notes the increased availability and convenience provided by online therapy platforms. 

Therapy can help participants learn more about ADHD, recognize their symptoms, and develop effective management techniques. However, individuals living with ADHD may find it difficult to attend in-person therapy sessions consistently. Online therapy platforms like BetterHelp can provide greater flexibility, availability, and affordability, allowing you to attend therapy sessions from wherever you have an internet connection. BetterHelp works with thousands of therapists—who have a wide range of specialties—so you’ll have a good chance of connecting with someone who can address your specific concerns regarding ADHD or similar mental health challenges. 


ADHD is a neurodevelopmental disorder characterized by hyperactivity, inattention, impulsivity, and other symptoms that can make everyday functioning more difficult. Despite these complications, ADHD is a treatable disorder. If you are living with ADHD or another mental health concern, consider connecting with a professional online. With the right support, you can navigate ADHD and continue to foster mental wellness.
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