What is ADHD?

Attention deficit hyperactivity disorder¹, more commonly known as ADHD, is a disorder usually diagnosed in childhood that can persist into adolescence and adulthood. The symptoms of ADHD can affect behavioral, cognitive, emotional, and social functioning. Characteristics such as difficulty focusing, inattention, and impulse control are typically seen in both children and adults.

Particularly in adulthood, ADHD can cause problems concentrating or remembering things. Some people find that they are unable to fulfill commitments and have difficulty staying organized.

Some people with ADHD have symptoms of hyperactivity, meaning they tend to move around or fidget and struggle with sitting still. Other characteristics of ADHD include impulsivity (or the tendency to make rash decisions), difficulties with interpersonal relationships, and being accident-prone. In tandem, these symptoms can lead to struggles² with self-esteem, poor academic or job performance, and other life problems.

ADD vs. ADHD

ADD³, or attention deficit disorder, is an outdated term that was used to describe a form of ADHD that is particularly linked with trouble paying attention or focusing (inattention). The switch from the diagnosis of ADD to ADHD occurred in 1994.

As it is diagnosed today, ADHD has three primary symptoms: inattention, hyperactivity, and impulsivity. Most diagnosed cases of ADHD are characterized by inattentiveness. This form of ADHD can be referred to by the following names:

• Inattentive ADHD
• ADHD, Inattentive Type
• ADHD without hyperactivity

Children with inattentive ADHD may not receive the same recognition for their challenges. They may be labeled instead as shy, careless, or being known to “have their head in the clouds.”

How common is ADHD?

An estimated 6.1 million children⁴ in the United States between the ages of two and 17 have been diagnosed with ADHD.

Boys are three times⁵ more likely than girls to be diagnosed with ADHD. Studies show that girls are diagnosed an average of five years later than boys (12 years old vs. seven years old), and up to 75% of girls with attention deficits may never receive an official diagnosis of ADHD.

An estimated 11 million adults⁶ in the United States have ADHD. Roughly two-thirds of children who are diagnosed with ADHD will have symptoms that persist into adulthood and will require continued treatment.

ADHD causes

It is not known for certain whether ADHD is caused⁷ solely by genetics, or whether a combination of genetics and external factors, such as environment and diet, play a role in the disorder. Current research suggests that ADHD is caused by structural, chemical, and connectivity differences in the brain, which are mainly caused by genetics.

Risk factors for ADHD

Some factors⁸ may increase your risk of developing ADHD, including:

• Genetics: Your likelihood of having ADHD increases if you have one or more blood relatives who have been diagnosed with the condition or another mental health disorder.
• Environmental toxins: Exposure to lead and other toxins, often found in paints and metal pipework in older buildings, may increase your risk of ADHD.
• Maternal behavior during pregnancy: Drug use, smoking, or alcohol use by a mother during pregnancy may contribute to a childhood’s likelihood of developing ADHD.
• Premature birth: ADHD is more common among children born prematurely (before the 37th week of pregnancy).

ADHD symptoms

The symptoms of ADHD begin in childhood but can continue into adulthood. Sometimes, the symptoms that are seen in childhood change and present themselves differently in adulthood.

In both children and adults, ADHD presents with a consistent pattern of three main symptoms: impulsivity (the tendency to act without thinking things through), hyperactivity (being overactive), and inattention (difficulty paying attention).

People with ADHD commonly experience combinations of the following symptoms⁹:

• Difficulty maintaining sustained attention during both required and enjoyable tasks (such as while reading, in a lecture, or in conversation)
• Overlooking or missing details or making careless mistakes
• Failing to follow through on tasks or instructions; starting tasks but easily losing focus or become sidetracked
• Difficulty organizing tasks or activities, such as keeping personal belongings in order, performing tasks in the right sequence, and meeting deadlines
• Aversion to tasks that required sustained focus or mental effort, such as homework, paperwork, or lengthy texts
• Losing or frequently misplacing important items, such as school supplies, wallets, keys, cell phones, or eyeglasses
• Forgetfulness in daily activities, such as doing chores, running errands, keeping scheduled appointments, and returning calls or messages
• Appearing lost in thought or seeming not to listen when being spoken to directly
• Becoming easily distracted by unrelated thoughts or stimuli

Some people with ADHD show signs of hyperactivity and/or impulsivity. These may include:

• Having trouble sitting still; constantly fidgeting or moving around while seated
• Running around or climbing things in inappropriate situations (in children) or feeling restless or agitated (in teenagers and adults)
• Excessive or nonstop talking
• Interrupting conversation or intruding on others’ activities
• Speaking out of turn, blurting out an answer before a question has been finished, or completing other people’s sentences
• Trouble waiting for one’s turn

Having one or more of these signs and symptoms does not guarantee that someone has ADHD. It is also important to remember that not every person with ADHD will show these symptoms in the same way or to the same degree. The symptoms of ADHD can also change over time, so your disorder may present differently in adulthood as it did when you were a child.

While many are normal in moderation, some of these signs and symptoms may be indicators of other disorders or mental health conditions, such as anxiety, depression, and certain learning disabilities.

If you suspect that you or your child may have ADHD, talk to your healthcare provider to determine whether a diagnosis may be possible.

ADHD in children

It is known that girls and boys show symptoms of ADHD differently¹⁰, though there is variation from child to child. In general, girls are less likely to act out in school other than possibly fidgeting or talking more than others.

Some girls with ADHD may be characterized as overly sensitive or distracted. Boys tend to display more signs of hyperactivity and have problems with self-control, such as ignoring a teacher’s instructions or directions in school.

Common symptoms¹¹ of ADHD in childhood include:

• Squirming, fidgeting, or having trouble sitting still
• Difficulty staying seated during meals or in class
• Inability to wait for their turn
• Frequently interrupting conversations
• Excessive talking
• Inability to play or work quietly
• Tendency to intrude on others’ personal space
• Constant moving, running, or climbing

ADHD in adults (h3)

Common symptoms of ADHD in adulthood¹² include:

• Feeling restless or fidgety
• Trouble sitting through meals, meetings, or movies
• Frequent mood swings and/or hot temper
• Impatience
• Chronic lateness
• Problems with memory or forgetfulness
• High distractibility
• Trouble starting and finishing tasks
• Disorganization
• Reckless or speedy driving
• Preference for a very active job
• Frequent interruptions during conversation
• Talking excessively and/or making inappropriate comments
• Low tolerance for frustration
• Tendency to draw quick conclusions

Complications from ADHD (h3)

Having ADHD can make it difficult to lead a balanced life. ADHD is known to be associated with¹³ the following potential complications:

• Unstable relationships
• Poor school or work performance
• Problems holding a job
• Financial issues
• Alcohol or drug misuse/abuse
• Frequent accidents (car accidents, etc.)
• Trouble with authority, such as law enforcement
• Poor physical/mental health
• Poor self-image
• Suicidal thoughts or attempted actions

If you or a loved one shows signs of suicide, call the National Suicide Prevention Lifeline at 1-800-273-8255.