What Is ADHD?

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

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)

What is 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 primary presentations the individual experiences. These subtypes are:

• Predominantly inattentive(ADHD-I) – Characterized by trouble concentrating on tasks, organizing, and focusing during conversations. 

• Predominantly hyperactive-impulsive (ADHD-H)– Characterized by fidgeting, behaving impulsively, and interrupting during conversations. 

• Combined type (ADHD-C) – Characterized by both inattentive and hyperactive-impulsive symptoms. 

Comorbid mental health conditions

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

Common comorbidities with ADHD include:

• Depressive disorders

• Anxiety disorders

• Substance use disorders

• 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, such as being easily distracted, making seemingly careless mistakes, forgetfulness, and difficulty feeling rewarded by or staying on tasks. 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 risk factors have been identified, including genetic, social, and environmental contributors. 

For example, ADHD researchers have demonstrated 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. 

Additionally, details from the CDC shows that boys are more than two times as likely to be diagnosed with ADHD as girls—though it’s possible this is related to underdiagnosis in girls rather than genuinely sex-based risk.

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%. That would mean that up to 74% of the incidence of ADHD may be explained by genetics.

• 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 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 neurotransmitters could be a major cause of the disorder. These brain differences in people diagnosed with ADHD can lead to deficiencies in dopamine and noradrenaline, neurotransmitters that are vital for mental processes including motivation, focus, and reward. Individuals with ADHD have also been found to have less gray and white matter in certain areas of the brain. These matter are responsible for processing incoming sensory and other information (gray matter) and sending information between areas of the brain as well as to the rest of the body (white matter).

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

ADHD symptoms and diagnosis

Particularly in children, it is often hard to distinguish between symptoms of ADHD and behavior that is neurotypical. This is why a diagnosis from a healthcare professional is the most reliable way to determine whether ADHD is present. 

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (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, and symptoms must have started before age 12.

Types of ADHD

Following are more details on the three different subtypes of ADHD listed in the DSM-V and their applicable symptoms. For all subtypes, adolescents 16 and younger must display at least six of the listed symptoms, while those 17 and older must display at least five symptoms.

Predominantly inattentive

The symptoms in this subtype primarily affect attention maintenance and working or other memory, and include:

• 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

• Avoiding or disliking activities that require long periods of sustained concentration

• Frequently losing or misplacing things (e.g., toys, pencils, homework)

• Easily distracted by external stimuli or internal thoughts

People with predominantly inattentive ADHD can and do often still experience hyperactive and impulsive symptoms, but don’t meet the criteria for predominantly hyperactive/impulsive type.

Predominantly hyperactive/impulsive

As with inattentive type, 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

Those with predominantly hyperactive/impulsive type may (and often do) still experience inattentive symptoms, but they still don’t meet the criteria for predominantly inattentive type.

Combined type 

This subtype is utilized for people who display a mix of characteristics and symptoms from both inattentive and hyperactive/impulsive types, rather than leaning toward one or the other subtype.

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 Psychiatric Association, a child with hyperactive/impulsive type ADHD may have trouble “waiting his or her turn,” struggle to “play or do leisure activities quietly,” or find it difficult to “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 focus on tasks. For many children, academic challenges are their first indication of the presence of ADHD. These difficulties 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. Questions to consider during your observation include:

• Does your child avoid lending others their toys, snacks, and games?

• Do they appear unwilling or unable to wait their turn?

• Do they interrupt others frequently?

• Do they have difficulty listening to instructions and finishing their tasks?

• Do they behave impulsively?

Your answers to these questions may prove useful in getting your child the diagnosis and treatment they need, should they have 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 highly variable hormones. Those who had milder symptoms in childhood may find that their symptoms are much more intrusive than before. Given the often-mounting scholastic demands during an individual’s teen years, challenges surrounding homework, projects, and other school-related activities may become more noticeable in an adolescent with ADHD. Comorbid conditions like anxiety, depression, or other mental health disorders may also signal the existence of previously undiagnosed 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

• Conflicts in relationships related to frequent interruptions, tangents, or perceived disinterest

• 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. This doesn’t mean that the disorder started in adulthood—rather, it means that ADHD symptoms that have been present since childhood were not diagnosed until adulthood, for one reason or another. 

It’s not unusual for parents, teachers, and other adults or peers to interpret symptoms of ADHD as laziness, disinterest, or other negative personality traits, which may discourage the individual from considering and seeking an ADHD diagnosis. Others may not have a diagnosis due to a lack of insurance coverage or high assessment costs, or they may be able to manage their symptoms well enough to get by under the radar until adulthood.

ADHD in adults can interfere with one’s career, relationships, and self-esteem, and may—as in childhood and adolescence—contribute to the development of comorbid mental health conditions, particularly depressive and anxiety disorders.

Individuals who are experiencing career challenges due to ADHD may be entitled to certain defenses in the workplace under the Americans with Disability Act, such as alterations to their schedule and responsibilities. 

If you have been experiencing the above symptoms, consider consulting a healthcare professional who can determine whether further screening is necessary.

How do professionals diagnose ADHD?

As discussed, ADHD can be difficult to identify. Almost all people live with at least some behaviors that technically count as potential symptoms of the disorder. It can also be hard to pinpoint ADHD symptoms in adults because many of them mimic symptoms of other mental health conditions. Typically, what separates a personality or other individual difference from a symptom is the severity. 

A persistent pattern of multiple symptoms that gets in the way of work, school, socializing, and more, is indicative of ADHD; forgetting where your keys are and struggling to focus once in a while—without any other persistent, intrusive symptoms—is probably not.

Regardless of age, an ADHD diagnosis will usually need to be provided by a mental health care 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. Psychotherapy, particularly cognitive behavioral therapy, can help those with the disorder develop coping mechanisms, address emotional challenges, and navigate comorbid disorders. Dedicated support groups may also be beneficial for some individuals.

As with many other conditions, experts suggest early intervention so that the individual can learn how to manage the disorder as soon as possible.

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 parenting practices that may make managing symptoms of a child’s ADHD more difficult—especially practices that typically work with other children but are ineffective or even problematic for a child with ADHD.

Stimulant and nonstimulant medications may also be 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. However, medications can also come with unpleasant side effects, or may interact with other lifestyle and health factors, so some people choose not to take them. 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 can provide greater flexibility, availability, and affordability.