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Attention deficit hyperactivity disorder (ADHD) is a type of neurological disorder called a neurodevelopmental disorder. ADHD affects your brain and nervous system, like all neurological disorders, but it also affects brain development.

ADHD is presumed to be present from birth. If left untreated, it can interfere with learning and the achievement of developmental milestones.

ADHD can lead to a wide range of symptoms related to inattention, hyperactivity, and impulsivity. In adulthood, untreated ADHD can cause difficulties with day-to-day functioning at home and at work.

Ahead, we’ll explore what the science says about ADHD and the brain.

Neurodevelopmental disorders are conditions that affect brain development in children and adolescents. The term neurodevelopmental disorder is relatively new. It was added to the “Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition” (DSM-5) as a category of diagnoses, many of which used to be called developmental disorders.

Like neurological disorders, neurodevelopmental disorders affect the structure or function of your brain or nervous system. This means that scientists have identified biological irregularities that can be seen in advanced imaging tests or treated with medications.

This is significant, because for a long time, people thought that the symptoms of conditions such as ADHD were behavioral — or that they could be fixed with discipline or better parenting.

Irregularities in the brain can cause behavioral issues, such as trouble with emotional regulation or impulsivity. They can also affect the way people think, learn, and interact with others.

How common is ADHD?

ADHD is one of the most common childhood health disorders. It affects almost 10% of children in the United States alone, according to the Centers for Disease Control and Prevention (CDC).

Because these conditions affect both the brain and behavior, children with neurodevelopmental conditions may be diagnosed and managed by a combination of the following doctors:

  • neurodevelopmental pediatricians
  • pediatric psychiatrists
  • pediatric psychologists
  • neurologists

Research on the biological aspects of ADHD has progressed in recent years. Using MRI images and CT scans, researchers can identify brain structures and measure their size. Using fMRI technology, researchers can track activity in the brain and watch how that activity changes while someone performs certain tasks.

Brain structure

Research has shown that ADHD is associated with variations in several different regions of the brain. A 2017 study of children and adults with ADHD used one of the largest data sets available to gather data on brain structure. They compared images gathered from 1,700 people with ADHD and more than 1,500 people without it.

According to the results, in people with ADHD, certain areas of the brain are smaller than average. These areas include subcortical structures deep within the center of the brain, such as the amygdala, accumbens, and hippocampus. These areas play a number of roles in cognition, particularly in emotional regulation and memory.

Researchers found that the differences between ADHD brains and non-ADHD brains were most pronounced in childhood. This supports the researchers’ theory that children with ADHD experience a delay in the development and maturation of certain brain structures.

Other research has looked at total brain volume and brain surface area. According to several studies, people with ADHD appear to have a reduced total brain volume. Additionally, some studies have shown a thinning of the cerebral cortex, which is the outermost layer of the brain.

Brain function

Brain function refers to the many processes that are taking place within your brain at any given time. Researchers have used fMRI technology to track activity in the brain while people perform different types of tasks, such as thinking, planning, and decision-making.

According to fMRI studies, people with ADHD have impairments in a variety of brain functions. In particular, researchers have found impairments in executive functions, such as planning, timing, attention, and working memory. Researchers have also found abnormalities in areas that involve emotional control and motivation.

Other research has noted differences in the reward processing networks of the brain. Some studies have found deficits in reward-related decision making. Other findings on this topic have been inconsistent, though.

But what do these study results mean, exactly? Well, it’s possible that these changes in brain structure and function lead to many of the symptoms that people with ADHD experience.

ADHD causes symptoms primarily related to inattention, hyperactivity-impulsivity, or a combination of both. Hyperactivity-impulsivity is most common in young children, whereas inattention is more common in older children and adolescents.

Symptoms of inattention may include:

  • having trouble with the details of activities
  • difficulty paying attention or keeping focus
  • trouble finishing or completing tasks
  • avoiding difficult activities or tasks
  • getting easily distracted and forgetting things
  • frequently losing important items

Symptoms of hyperactivity-impulsivity may include:

  • constantly fidgeting while seated
  • frequently needing to move or walk around
  • feeling restless and moving sporadically at times
  • having trouble engaging in activities quietly
  • talking excessively or interrupting people

People with ADHD may also struggle to keep their personal spaces organized.

ADHD symptoms may stem from abnormalities in the brain, but medications can help modify the effects.

The goal of ADHD treatment is to lessen symptoms and improve overall functioning in daily life. Usually, this is achieved through a combination of medication, therapy, and adaptive behaviors.

Medication

Medications can help lower the chronic symptoms of ADHD, which can greatly improve everyday functioning and overall quality of life. Two of the most common types of medications prescribed for ADHD are stimulants and nonstimulants:

  • Stimulants: Stimulant medications include options such as Adderall, Vyvanse, and Ritalin. They can help reduce the symptoms of ADHD by increasing levels of dopamine and norepinephrine in the brain.
  • Nonstimulants: Nonstimulant medications, such as Strattera, Kapvay, and Intuniv, can also help improve the symptoms of ADHD — such as impulsivity and inattention — by changing the levels of certain neurotransmitters in the brain.

Therapy

Therapy can help people with ADHD thrive in their daily lives. Different types of talk therapy can be used to help people develop coping skills that help them regulate their emotions, change problem behaviors, and set goals.

Different therapeutic approaches for ADHD may include:

  • Behavioral therapy: Behavioral therapy, such as cognitive behavioral therapy, can help people with the thoughts, feelings, and behaviors that shape their daily lives.
  • Family therapy: Family therapy — as well as marriage therapy for adults with ADHD — is a therapeutic approach that can help improve the way that symptoms of ADHD affect home life and relationships.
  • Parent training: Parent training can teach parents of children with ADHD how to help their children improve not only their behaviors but also their self-esteem, through cognitive behavioral techniques.

Adaptive behaviors

Changing problematic behavior is an additional strategy that can help improve the day-to-day quality of life for people with ADHD. This means identifying activities, parts of your schedule, or unhealthy tendencies that may worsen your ADHD symptoms or impede treatment.

In children, for example, this may involve developing new habits that can be followed at school or at home. This could look like receiving personalized academic accommodations at school, or using calendars and other organizational tools at home.

In adults, attending weekly or monthly support groups is a great way to receive support and advice from peers living with ADHD.

ADHD can change the way that the brain develops — and in turn, the way that it functions.

Research has shown that these physical changes in the brain can lead to the many different symptoms of ADHD, including decreased attention and increased hyperactivity. ADHD is commonly diagnosed in childhood, but it can impact people of all ages.