Attention deficit hyperactivity disorder (ADHD) is a chronic condition characterized by impulsive behavior, inattention, and hyperactivity.

It’s usually diagnosed in childhood, but the symptoms of ADHD can continue to go unrecognized throughout adolescence and adulthood. Given this, it’s possible someone may not receive a diagnosis until they are an adult. With proper treatment, children and adults with ADHD can live successful, productive lives.

Attention deficit disorder (ADD) is an older term for what’s now known as ADHD. Some people still use the terms ADD and ADHD interchangeably and may call the condition ADD if a child only has trouble focusing and isn’t hyperactive. However, the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-5) — the resource professionals use to diagnose and treat mental health conditions — recognizes ADHD as the correct term.The condition was commonly referred to as ADD until 1987, when “hyperactivity” was added to the name in the third edition of the DSM. The revised fourth edition of the DSM, published in 1994, divided ADHD into specific subtypes. It took into account the fact that an individual could have an ADHD diagnosis without experiencing symptoms of hyperactivity, according to research published in the journal ADHD Attention Deficit and Hyperactivity Disorders.There are three forms — or “presentations” — of ADHD, as described in the DSM-5, published in 2013.

1. Predominantly Hyperactive-Impulsive

People with this type of ADHD mostly struggle with hyperactivity and impulsiveness, though they may also have some symptoms of inattentiveness.

Hyperactivity can manifest as constant movement and excessive fidgeting and talking. In adults, this may take the form of exaggerated restlessness and an activity level that other people find tiring, according to the National Institute of Mental Health (NIMH).

Impulsivity often takes the form of making important decisions and taking action without thinking through the consequences, especially when those actions might be harmful or detrimental and the resulting effects long-lasting.

Impulsivity is also marked by a desire for instant gratification. In social situations, an impulsive person might interrupt others to an extreme degree and be quick to grow impatient, frustrated, or angry.

2. Predominantly Inattentive

People with this presentation of ADHD predominantly experience symptoms of inattentiveness, though they may also have some problems with hyperactivity and impulsiveness.

Inattentiveness is characterized by struggling to stay focused, being easily distracted from the task at hand, having a hard time with attention to detail, and a lack of organization. This can result in professional and personal difficulties because of a lack of attention to detail and an inability to make important deadlines, meetings, and social functions.

3. Combined Hyperactive-Impulsive and Inattentive

People who have this presentation of ADHD have symptoms of hyperactivity, impulsiveness, and inattentiveness.

The signs and symptoms of ADHD may differ based on the person’s age and presentation of the disorder.

According to Russell Barkley, PhD, a retired former clinical professor of psychiatry at the Virginia Commonwealth University Medical Center in Richmond, ADHD symptoms arise in a set of mental abilities called the executive functions.

The executive functions encompass a range of processes in the brain, mostly in the frontal areas, that control and manage other brain activities that allow us to get work done — whether it’s creative or more routine, to set and achieve goals, and to take into consideration the potential consequences of our actions and regulate our behavior.

Symptoms of ADHD in children may include:

• Talking excessively

• Squirming and fidgeting

• Trouble sitting still

• Impatience

• Disruptiveness

• Difficulty waiting for a turn

• Daydreaming

• Difficulty following instructions

• Forgetfulness in daily activities

• Trouble focusing

In adults, ADHD symptoms may take the form of:

• Impulsiveness

• Frequent interrupting

• Restlessness

• Inability to concentrate

• Lack of organization and follow-through

• Difficulty meeting deadlines

• Frequent mood swings

• Difficulty coping with stress

According to the Centers for Disease Control and Prevention (CDC), 15.6 percent of American boys and 8.2 percent of girls have been diagnosed with ADHD (but that discrepancy may be due to underdiagnosis in girls). Experts aren’t sure what causes ADHD. As is the case with most mental health conditions, it is thought to be an interplay of biological, social, and psychological factorsNeuroimaging studies using magnetic resonance imaging (MRI) scans to look at brain structure have found associations between certain neural circuits in the brain and ADHD. These circuits are related to sustained attention, control of inhibitions, motivation, and regulation of emotions.

Not all people with ADHD show the same circuits or changes in circuits, but certain brain differences are more common in people with ADHD than those without it.

Several factors may increase a child’s likelihood of developing ADHD.

Genetics

Current evidence suggests ADHD has a genetic component — meaning it seems to run in some families; however, research has yet to identify the specific genes associated with ADHD. Scientists believe multiple genes may be involved because of the complexity of the condition, according to the National Human Genome Research Institute. These genes may have to do with the processes of certain neurotransmitters, or chemical messengers in the brain, such as dopamine, which play a role in the brain’s reward systems and in regulating impulsivity and movement.

Environmental Exposure to Toxins and Chemicals

Exposure to substances, especially lead, may be a contributing factor. Studies have indicated a relationship between ADHD and levels of lead in the bloodstream.

Although research has consistently shown a connection between lead exposure and ADHD, it’s important to note that it’s not the only cause of ADHD, nor does lead exposure guarantee that a child will develop ADHD.

Research has also found that other environmental toxins, such as bisphenol A (BPA), are potentially problematic for brain health. A 2025 systematic review concluded that exposure to endocrine disruptors, such as BPA, have an association with ADHD in children. However, more research is needed to clarify a causal relationship.

Alcohol or Tobacco Use During Pregnancy

A number of studies has found associations between tobacco use during pregnancy and ADHD symptoms in children. But more recent research has questioned whether substance use directly causes ADHD.

While a 2026 umbrella review of systematic reviews and meta-analyses published in the Journal of Psychiatric Research on smoking during pregnancy and its risk of ADHD on offspring did find an association, it concluded that evidence was lacking to establish a causal relationship. Rather, it suggests genetic and familial factors may be at play, and more high-quality research is needed to further investigate.A 2022 meta-analysis and systematic review likewise found no clear causal link between prenatal smoking and ADHD diagnosis on offspring. It also noted more research is needed to investigate possible effects of alcohol consumption during pregnancy and ADHD risk for the child.

Still, pregnant people should refrain from alcohol consumption and smoking because of other well-established risks, including premature birth, low birth weight, and fetal alcohol syndrome.

Traumatic Brain Injury (TBI)

TBI in early childhood has been linked to the development of psychiatric disorders. Among those disorders, ADHD is the most common, notes a study published in the July 2021 issue of JAMA Pediatrics. TBI is not uncommon — more than 214,000 Americans are hospitalized to treat it each year.

Premature Birth or Low Birth Weight

Some research has suggested that the lower a baby’s birth weight or the earlier their birth is, the greater the risk they have of developing ADHD.

Diet and Behavioral Factors

Excessive sugar or food additives in one’s diet and excessive screen time (television, smartphones, tablets, and computers) are associated with ADHD. For instance, one small study published in January 2022 in BMC Pediatrics suggested that certain eating patterns, such as high sugar consumption, were more common in children with ADHD than in those without ADHD.

While these factors may affect or exacerbate symptoms, research doesn’t support claims that they cause ADHD.

ADHD affects more than 4 percent of adults in the United States, according to the NIMH. But that statistic includes only adults who have been formally diagnosed, so the actual number is likely much higher.

Although many people struggle at times with losing focus, getting distracted, and acting impulsively, these behaviors are more severe and more frequent for people who have ADHD. Without proper identification and treatment, these behaviors negatively affect their quality of life, whether it’s at work, school, or home.

Furthermore, many adults with ADHD don’t know they have it; they may only know that everyday tasks are challenging. Symptoms can change over time. Some people notice that their symptoms improve as they age, while others continue to struggle.

Such discrepancies may contribute to gender- and racial-related underdiagnosis of ADHD. Girls and women more often present with the inattentive subtype of ADHD, and their behavior may sometimes be characterized as less outwardly disruptive, which may be one reason many don’t receive a proper diagnosis until adulthood. Research has also found that Black, Hispanic, and Asian children were significantly less likely to be diagnosed with ADHD or receive treatment than white children.There’s no single ADHD test used to diagnose the disorder. A thorough evaluation by a professional — such as a psychologist, psychiatrist, pediatrician, or clinical social worker — is necessary for a proper diagnosis. This will help to rule out other conditions and examine possible coexisting conditions.

The process involves several steps, and your healthcare provider may perform a full medical exam, get a detailed medical history, and conduct interviews with family members to gather an in-depth personal history.

The DSM-5 requires that ADHD diagnoses include the severity of one’s condition, from mild to moderate to severe. This is because severity can vary throughout one’s life.

There’s no cure for ADHD, but a comprehensive treatment approach can help people manage their symptoms and thrive. ADHD treatment usually involves medication, certain behavioral strategies, and lifestyle changes intended to help with focus and organization.

For children ages 4 to 6 years old with ADHD, the American Academy of Pediatrics (AAP) recommends behavioral therapy as a first-line treatment before medication. Medication is recommended for children age 6 and older.

The most common medications used to treat ADHD include stimulants, nonstimulants, and sometimes antidepressants.

People with ADHD may also benefit from counseling — especially behavioral therapy — to improve behaviors and social skills. Parents and other family members may participate in counseling to develop strategies to support their loved one with ADHD and navigate challenges.

Medication Options

Stimulants are the most commonly prescribed type of ADHD medication. Often used to improve focus and block out distractions in people with ADHD, stimulants are considered the most effective class of ADHD drugs, according to Cleveland Clinic. However stimulants can also increase heart rate and blood pressure, so it’s important to disclose any history of a heart condition with your doctor, who can help you weigh the risks and benefits of using this treatment.

Nonstimulant medications can be used for ADHD in people who haven’t had success with a form of stimulant medication or who can’t take stimulants.

ADHD medications are available in different formulations: short-acting, intermediate-acting, and long-acting. Some side effects of these drugs are suppressed appetite, difficulty sleeping, and irritability, according to Cleveland Clinic. A doctor can determine which medication for ADHD is best, describe possible side effects, and explain the pros and cons of medication treatment for ADHD in general.

Complementary and Integrative Therapies

Although there are many types of supplements and diets people have tried for ADHD, most don’t have enough scientific evidence for experts to recommend using them as a first line of treatment. Always check with your doctor before trying a new diet or supplement because it could interact with ADHD medications and cause unwanted side effects or other health problems.

According to the AAP, the following complementary and integrative therapies are not supported by scientific evidence and are not recommended for the treatment of ADHD:

• Megavitamins and mineral supplements

• Anti-motion-sickness medication (intended to treat the inner ear)

• Candida yeast infection treatment

• Electroencephalogram (EEG) biofeedback (training intended to increase brain wave activity)

• Applied kinesiology (intended to realign bones in the skull)

• Decreasing sugar consumption

• Optometric vision training

Certain lifestyle changes and accommodations can help create a better environment for people with ADHD. These include:

• Routines and schedules

• Reorganization of your home or workspace

• Physical reminders of tasks at hand

• Removal of distractions

Although genetics are thought to be one of the main risk factors for ADHD, there are a few health behaviors that may reduce the likelihood that a child will have the disorder, according to Mayo Clinic.

• During pregnancy, avoid any activities or substances that could harm the development of the fetus. Examples include alcohol, smoking, and recreational drugs.

• Children should be protected from pollutants and toxins like lead paint or cigarette smoke.

• Although a direct link between screen time and ADHD has not been established, experts recommend limiting the amount of TV and video games in the first five years of life.

ADHD is a chronic condition. The long-term prognosis of ADHD and the way its symptoms present depends on whether a person is receiving treatment with medication, behavioral or talk therapy, or both.

Untreated ADHD can lead to several emotional and physical complications, according to Mayo Clinic, including:

• Poor self-esteem

• Accidents and injuries

• Substance abuse

• Delinquent or risky behavior

• Trouble interacting with peers and relationship difficulties

More than two-thirds of people with ADHD have at least one other coexisting condition with symptoms that can sometimes be hard to distinguish from those of ADHD.

Children with ADHD may be more likely to have:

• Anxiety

• Bed-wetting

• Bipolar disorder

• Conduct disorder, a condition characterized by behaviors like lying, stealing, fighting, or bullying

• Depression

• Learning disabilities

• Oppositional defiant disorder (ODD), a condition characterized by a pattern of hostile behavior toward authority figures

• Sleep disorders

• Tourette’s syndrome, a neurological disorder characterized by nervous tics and repetitive mannerisms

• ADHD is a chronic condition that affects an estimated 4.4 percent of adults and 12 percent of children. The condition is characterized by impulsive behavior, inattention, and hyperactivity.

• The three main presentations of ADHD are predominantly hyperactive-impulsive, predominantly inattentive, and combined hyperactive-impulsive and inattentive. Each is characterized by specific symptoms and experiences.

• There’s no ADHD test. Rather, diagnoses come as the result of examinations from medical professionals, who can provide medical intervention and behavioral therapy, as appropriate.