What Is ADHD? Meaning, Signs, Causes, And How To Cope

ADHD, or Attention Deficit Hyperactivity Disorder, is a neurodevelopmental disorder that affects both children and adults. It is characterized by signs such as difficulty with focus, hyperactivity, and impulsivity.

ADHD can make it challenging to complete tasks, follow through on responsibilities, and interact with others. It is important to seek diagnosis and treatment from a healthcare professional if you or a loved one is experiencing signs of ADHD.

It is common for everyone to experience some level of difficulty with attention or controlling impulsive behavior, but for those with ADHD, the problems can be so pervasive and persistent that they can interfere with every aspect of their lives.

The first known documentation of ADHD was from 1902, when it was coined for some children. Since then, the condition has been given numerous names, one of these being attention deficit disorder (ADD).

Human head with many thoughts, task and ideas. Child or adult with ADHD syndrome. Attention deficit hyperactivity disorder. Mental health, psychology concept. Vector flat style illustration.

ADD is often still used today, although the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) only lists ADHD to describe individuals with this disorder, regardless of whether they display signs of hyperactivity.

To find out more about the differences between ADD and ADHD, see the following article: ADD vs. ADHD: What are the Differences?

ADHD is usually first diagnosed in childhood, believed to affect around 11% of school-aged children.

Children with ADHD usually have difficulties concentrating on the task at hand, find that their attention can shift between several things at once, and they may be unable to sit still for long periods of time.

The signs of ADHD are thought to continue into adulthood for more than three-quarters of the cases (Brown, 2013).

While the signs can change with time, they can still interfere with an adult’s functioning, specifically in their relationships, health, work, and finances.

It is worth noting that many people might have ADHD without realizing as many can go undiagnosed. Many may realize in adulthood that they have ADHD, or go their whole lives without a formal diagnosis.

Signs of ADHD

It’s important to understand that experiencing some signs of ADHD does not automatically mean someone has the disorder. Many ADHD signs can be common and relatable, but they do not necessarily indicate ADHD.

Additionally, individuals with ADHD may not exhibit all signs or traits and may have varying levels of each trait depending on the situation. This list of signs is not exhaustive.

some of the signs of ADHD
Some of the common signs of ADHD

General signs

Below are some of the common experiences and traits individuals with ADHD may report.

  • Tasks, homework, or chores may take a long time to complete

  • Often forgetful – they may forget birthdays, instructions, or homework

  • They are often accused of not trying or appearing not to care

  • May appear to underachieve in some areas of life such as in education

  • Have a low tolerance for boredom

  • Issues with time management, such as managing when to get up, getting to work or school on time, or attending appointments.

  • They may miss important information because they have ‘zoned out’

  • They may hyper-focus on tasks that interest them, to the detriment of their basic needs, such as eating and sleeping.

  • They might find reading a book from start to finish challenging or may find it difficult to take in what they have read

  • They may be very impulsive, such as purchasing items they may not necessarily need just because they want them at that moment.

  • They may face financial problems due to impulsive spending and forgetting to pay bills

  • They may have trouble getting to sleep, staying asleep, and waking up on time

  • Often might not trust themselves to do what they say they will

  • They may have low self-esteem after years of not meeting their and other people’s expectations.

  • Problems with executive functions, such as not being able to plan out how to start and complete tasks from start to finish

  • Difficulties regulating emotions which can manifest as difficulty managing and expressing their emotions in appropriate ways, often leading to impulsive or intense emotional reactions.

Signs in children

ADHD can present differently in children and adults.

In children, the signs of ADHD, such as attentional difficulties, can contribute to problems in school, such as getting low grades or getting into trouble for disruptive behaviors.

Children with ADHD may sometimes need more support in developing independent skills, and may demonstrate behaviors that are typical of younger children. Some children with ADHD may experience mild delays in language, motor skills, or social development.

Likewise, children with ADHD may have lower frustration tolerance, difficulty controlling their emotions, and may often experience mood swings.

Signs in adults

In adulthood, ADHD can change to some extent. The hyperactive signs may become less visible, finding they can relatively sit still despite any internal restlessness.

This internal restlessness may present in the form of rapid and changing thinking, thoughts, and ideas.

This is not to say that some adults with ADHD are less visibly restless. As with each sign of ADHD, they can present differently in everyone.

The inattentive signs of ADHD usually remain consistent, although adults can usually have more control over their environments than children.

While children typically must remain at a desk most of the day, some adults can design a life or choose a job that suits their ADHD signs.

So, instead of choosing a career that involves sitting at a desk, they may choose a career that involves moving around, physical labor, or traveling to different places for work.

However, for many reasons, individuals may not be able to be in a career that suits their ADHD.

Adults with ADHD may have difficulties with their peers and social situations, have inconsistent performance at work and engage in risky behaviours.

Adults with ADHD may have chronic feelings of frustration, guilt, or shame for not being able to navigate life and work as easily as others. This can especially be the case if an adult misses a diagnosis of ADHD and cannot put an answer to why they have difficulties.

Some of the negative outcomes people with ADHD may face can include not being able to keep a job, becoming bankrupt due to issues managing finances, relationship problems, and addictions.


The DSM-5 criteria for ADHD list three presentations of the condition that people with the condition fall into predominantly inattentive presentation, predominantly hyperactive-impulsive presentation, and combined hyperactive-impulsive and inattentive presentation.

Below are the types of presentations and some of the traits associated with each one:

The combined presentation of ADHD is characterized by traits of both the predominantly inattentive and predominately hyperactive-impulsive presentations.

It’s worth noting that these traits can overlap and that some individuals may have a mix of inattentive and hyperactive-impulsive signs.

Additionally, the severity of signs can vary between individuals, and some may experience signs that are not listed here. It’s important to consult with a medical professional for an accurate diagnosis and treatment plan.

What Causes ADHD?


There is uncertainty surrounding the causes of ADHD, although it is generally believed to have neurological and genetic origins. More than 20 genetic studies have demonstrated evidence that ADHD is strongly inherited.

This means that if someone has ADHD, there is a good chance that they have a family member who also has the condition.

Brain differences

Research suggests that there is a structural difference in the brains of those with ADHD compared to those who do not have the condition (Bonath et al., 2016).

It was found that those with ADHD had reduced grey matter volumes in their anterior cingulate cortex, occipital cortex, cerebellar regions, and bilateral hippocampus/amygdala.

This reduction in grey matter volume could explain why people with ADHD have attentional problems since grey matter is involved in learning, memory, cognitive processes, and attention.

However, whether ADHD is the cause or effect of these brain differences is debatable.

Environmental factors

There are believed to be some factors in the environment that may increase the likelihood of someone having ADHD:

  • Exposure to lead or pesticides in early childhood

  • Premature birth or low weight at birth

  • Brain injury

It has been believed in the past that certain environmental factors may cause ADHD, although these have not been found to be the case.

Some of the factors that do NOT cause ADHD include watching excessive amounts of TV, eating sugar, family stress, parenting styles, and traumatic experiences.

Even though environmental factors such as family stress do not cause ADHD, they can change the way ADHD presents itself and may result in additional problems such as anti-social behaviors (Langley et al., 2010).

Researchers are continuing to study the exact relationship between ADHD and environmental factors but point out that there is no single cause that can account for all cases of ADHD.

Dopamine levels

Underlying differences in the brain are likely to be an underlying cause of ADHD, with some researchers looking at dopamine as a possible contributor.

Dopamine is a chemical of the brain that regulates emotional responses and is involved in motivation, feelings of pleasure, and rewards.

dopamine pathways
Dopamine pathway in the human brain.

People with ADHD may have different levels of dopamine compared to people without ADHD (Volkow et al., 2009).

Studies suggest that one of the reasons for this difference is because people with ADHD have more of a protein called dopamine transporters in their brain (Dougherty et al., 1999). These proteins can reduce dopamine levels in the brain, which may contribute to ADHD signs.

Studies also suggest that the dopamine pathway involved in reward and motivation may play a role in ADHD (Johansen et al., 2009). While more research is needed, some studies have found that a specific type of dopamine transporter may affect certain traits of ADHD, such as mood instability (Jeong et al., 2015).

Co-existing conditions

More than two-thirds of people who have ADHD also have at least one other co-existing condition.

Occasionally, ADHD may overshadow other conditions, making it harder to notice.

Likewise, the other condition may overshadow ADHD, making it harder to recognize ADHD signs.

Mood disorders

Studies suggest that up to 53.3% of adults with ADHD may also have depression (Katzman et al., 2017).

Approximately 14% of children with ADHD have depression compared to 1% of children without ADHD. Up to 20% of those with ADHD may also show signs of bipolar disorder.

Typically, the ADHD signs will occur first, followed by the mood disorder, perhaps because of the struggles those with ADHD face.


Up to 30% of children and 53% of adults with ADHD may also have an anxiety disorder. Some anxiety disorders include generalized anxiety disorder, social anxiety, and obsessive-compulsive disorder (OCD).

People with ADHD may find it difficult to keep up with daily tasks and make and maintain relationships, so this could increase anxious feelings as a result.

Likewise, people with ADHD are more likely to experience an anxiety disorder compared to those without ADHD.

Disruptive behavior disorders

About 40% of people with ADHD also have an oppositional defiant disorder (ODD). Signs of this condition involve excessive arguing, losing one’s temper, a refusal to follow the rules, a tendency to blame others, and anger.

Conduct disorder (CD) is another behavioral disorder that can occur in around 27% of children, 45-50% of adolescents, and 20-25% of adults with ADHD.

Children and adolescents with CD may be aggressive to others, destroy property, lie, steal, or skip school. Adults, meanwhile, may exhibit behaviors that can get them in trouble with the law.

Tic and Tourette syndrome

Less than 10% of those with ADHD have tics or Tourette syndrome, but over 60-80% of those with Tourette syndrome have ADHD.

Tics include sudden, rapid, involuntary movements or vocalizations. Tourette syndrome is rarer but most severe, involving making involuntary noises or movements on an almost daily basis for years.

Learning disorders

Up to 50% of people with ADHD have a learning disorder, whereas 5% of children without ADHD have a learning disorder, making this a common condition.

Types of common learning disorders include dyslexia and dyscalculia, which can involve problems with how individuals acquire or use new information. 12% of children with ADHD have speech problems compared with 3% of those without ADHD.

These extra challenges can make it harder for a child to manage at school and can worsen feelings of anxiety and depression.

ADHD in Girls and Women

ADHD is a condition that is more commonly diagnosed in males than females, typically three times as many males are diagnosed.

This may have led to some stereotypes that ADHD is a condition associated with boys who cannot keep still and are disruptive. However, there are likely many (cisgender) girls and women who are not diagnosed because their signs of ADHD are being missed.

The discrepancy that males are diagnosed more than girls on a ratio of 3:1 highlights that many girls with ADHD are likely to remain unidentified and untreated.

This leads to implications that without a diagnosis, girls are likely to suffer more long-term social, educational, and mental health outcomes.

Much of the available evidence on ADHD often draws on predominantly male-based samples due to the presumably higher prevalence of ADHD in males.

More girls with ADHD may fall more into the predominantly inattentive presentation of ADHD.

The inattention signs may present as being easily distracted, overwhelmed, and lacking in effort and motivation.

The less overt signs of ADHD in girls mean that they are less likely to be obvious to others, meaning they are less likely to get a referral for an evaluation.

Signs of ADHD may become more obvious in females later in life, often during periods of social or educational transitions or when trying to navigate the world of work.

A 2020 consensus summarised key points for the detection of ADHD in females:

  • Females present with both inattentive and hyperactive-impulsive signs

  • Severity of ADHD signs may be lower in females than in males, particularly for hyperactive-impulsive signs

  • Low mood, emotional lability, or anxiety may be especially common in females with ADHD

  • Emotional regulation problems may be more severe/common in girls with ADHD

  • Girls with ADHD are vulnerable to bullying

  • There is an increased school drop-out and academic underachievement

  • They tend to have decreased self-esteem and self-concept

  • They may not show as many behavioral problems commonly associated with males

  • Compensatory behaviors may mask behaviors and impairments

  • Dysfunctional strategies such as alcohol or drug use may be used to cope with emotional problems, social isolation, and rejection (Young et al., 2020).

Some girls and women with ADHD become competent at camouflaging their struggles using compensatory strategies, which may result in underestimating their underlying problems.

It’s not uncommon that females with ADHD are treated for anxiety or depression in the first instance.

Before a diagnosis, girls may have been given labels such as ‘chatterbox,’ ‘drama queen,’ or ‘tomboy.’ Having a diagnosis of ADHD can help free them from these labels that may have been attributed to them.

To conclude, it is important not to discount ADHD in females just because they may not display the behavioral problems commonly associated with males.

Can ADHD be Managed?

Managing ADHD often requires medical, educational, and psychological intervention.

This comprehensive approach is sometimes called ‘multimodal’ and, depending on the age of the individual, may include the following:

  • Parent training

  • Medication

  • Skills training

  • Counseling

  • Behavioral therapy

  • Educational supports

  • Educational regarding ADHD


ADHD medications come in two types: stimulant and non-stimulant. Stimulants may help people with ADHD focus better by increasing dopamine levels in the brain.

Common stimulant medications include Ritalin, Adderall, and Vyvanse. However, these medications can have side effects like addiction, sleep problems, or heart problems.

Non-stimulant medications are not as commonly prescribed as stimulant medications and are more often used for those with severe anxiety. They work differently than stimulants by blocking the reuptake of neurotransmitters like norepinephrine and dopamine, resulting in increased levels in the brain. Popular non-stimulant medications include Wellbutrin (Bupropion) and Strattera (Atomoxetine).

Behavior therapy

For some, behavior therapy can help people with ADHD learn the skills required to control some of their signs.

The goal of behavior therapy is to replace unhelpful behaviors with more helpful ones. This therapy can teach people strategies to improve problem areas like organization, focus, impulse control, or anything else that is an issue for those with ADHD.

Many find that behavior therapy can help them effectively manage their ADHD signs without using medications. Although behavior therapy does not affect brain chemistry, it can teach people skills that make it easier to navigate at school, work, home, and in relationships.

For children, behavior therapy usually uses the whole family approach to change behaviors. This therapy can also investigate how negative actions are responded to in a child’s home.

Sometimes the parents can unintentionally reinforce negative behaviors. Therefore, a whole family approach can ensure the primary people in the child’s life know how to manage negative behaviors and reinforce positive ones.

Cognitive behavioral therapy

According to the Centers for Disease Control and Prevention (CDC), behavioral therapy, as well as cognitive behavioral therapy (CBT) can help reduce signs in children with ADHD.

CBT can help people to recognize how their thoughts affect their behaviors so that they can reframe these thoughts so they have more helpful or realistic ones and, thus, more control over their signs.

CBT involves working with a therapist to notice any thought and behavioral patterns, challenge negative thoughts, cope with stress, deal with stressful obligations, and learn new ways to manage everyday life.

As well as helping with ADHD, CBT can help people to manage other conditions which may coexist alongside their ADHD, such as mood and anxiety disorders.

How to cope with ADHD

Alongside medication and therapeutic treatments, there are some ways in which individuals with ADHD can implement into their lives to help manage or cope with their signs and to navigate everyday life:

  • Having a consistent schedule with structure and regular expectations.

  • Making lists of things that need doing daily and adding to them when new ideas emerge.

  • Keeping a calendar and setting reminders to minimize the chance that important events or appointments get forgotten.

  • For children – they can write down homework assignments and keep everyday items such as toys and backpacks in assigned spots, so they are less likely to get lost. A child’s parent can also establish structure around meals, homework, and playtime.

  • Breaking tasks into manageable pieces and ensuring regular break times can help with feeling overwhelmed. Taking breaks when studying or working and leaving the room, going for a walk, or doing another task, can help to let out energy and help with feelings of boredom and lack of focus.

  • Simplify and organize life – e.g., assign specific quiet places to read or undertake a hobby to take a break from everyday chaos.

  • Reduce unnecessary distractions – distractions such as TV and video games could encourage impulsive behaviors and can be better regulated.

  • Undertaking regular exercise can help burn energy and stimulate the brain in a healthy way. This can help to focus attention on specific movements and decrease impulsivity, help concentration, and decrease the risk of anxiety or depression.

  • Regulate sleeping patterns – cutting down on sugar, caffeine, and screen time as much as possible can help with establishing a sleep pattern, as a lack of sleep can exacerbate inattention, hyperactivity, and recklessness.

  • Promoting wait times – pausing to consider actions can encourage thoughtful responses.

  • Breathing exercises in times of feeling overwhelmed or when the brain is having multiple thoughts at once can help to calm down.

  • Other relaxation exercises such as yoga, tai chi, mindfulness, meditation, and spending time outdoors can help calm overactive minds and ease signs.

In Sedgwick et al. (2019), interviews were conducted with individuals with ADHD, and some participants expressed how relaxation, such as mindfulness, helps them:

‘because an ADHD brain wants to go on and mindfulness actually wants to do quite the opposite…so whilst mindfulness practice is not the easiest thing for somebody with ADHD to do…even in a limited way…I find it quite helpful…. mindfulness practice, I think is potentially one of the most useful things that an ADHD person could learn…’

Further Reading

Faraone, S. V., Sergeant, J., Gillberg, C., & Biederman, J. (2003). The worldwide prevalence of ADHD: is it an American condition?. World psychiatry, 2(2), 104.

Kooij, J. J. S., Bijlenga, D., Salerno, L., Jaeschke, R., Bitter, I., Balazs, J., … & Asherson, P. (2019). Updated European Consensus Statement on diagnosis and treatment of adult ADHD. European psychiatry, 56(1), 14-34.

Danielson, M. L., Bitsko, R. H., Ghandour, R. M., Holbrook, J. R., Kogan, M. D., & Blumberg, S. J. (2018). Prevalence of Parent-Reported ADHD Diagnosis and Associated Treatment Among US Children and Adolescents, 2016. J Clin Child Adolesc Psychol, 47(2), 199-212.

Bauermeister, J. J., Shrout, P. E., Chávez, L., Rubio‐Stipec, M., Ramírez, R., Padilla, L., … & Canino, G. (2007). ADHD and gender: are risks and sequela of ADHD the same for boys and girls?. Journal of Child Psychology and Psychiatry, 48(8), 831-839.

Skogli, E. W., Teicher, M. H., Andersen, P. N., Hovik, K. T., & Øie, M. (2013). ADHD in girls and boys–gender differences in co-existing symptoms and executive function measures. BMC psychiatry, 13(1), 1-12.

Ghanizadeh, A. (2012). Psychometric analysis of the new ADHD DSM-V derived symptoms. BMC psychiatry, 12(1), 1-6.

Gershon, J., & Gershon, J. (2002). A meta-analytic review of gender differences in ADHD. Journal of attention disorders, 5(3), 143-154.


Bonath, B., Tegelbeckers, J., Wilke, M., Flechtner, H. H., & Krauel, K. (2018). Regional gray matter volume differences between adolescents with ADHD and typically developing controls: further evidence for anterior cingulate involvement.  Journal of attention disorders, 22( 7), 627-638.

Centers for Disease control and Prevention. (2021, September 23). Attention-Deficit/ Hyperactivity Disorder (ADHD). https://www.cdc.gov/ncbddd/adhd/diagnosis.html.

Dougherty, D. D., Bonab, A. A., Spencer, T. J., Rauch, S. L., Madras, B. K., & Fischman, A. J. (1999). Dopamine transporter density in patients with attention deficit hyperactivity disorder.  The Lancet, 354 (9196), 2132-2133.

Jeong, S. H., Choi, K. S., Lee, K. Y., Kim, E. J., Kim, Y. S., & Joo, E. J. (2015). Association between the dopamine transporter gene (DAT1) and attention deficit hyperactivity disorder-related traits in healthy adults.  Psychiatric genetics, 25 (3), 119-126.

Johansen, E. B., Killeen, P. R., Russell, V. A., Tripp, G., Wickens, J. R., Tannock, R., Williams, J. & Sagvolden, T. (2009). Origins of altered reinforcement effects in ADHD.  Behavioral and Brain Functions, 5 (1), 1-15.

Katzman, M. A., Bilkey, T. S., Chokka, P. R., Fallu, A., & Klassen, L. J. (2017). Adult ADHD and comorbid disorders: clinical implications of a dimensional approach.  BMC psychiatry, 17 (1), 1-15.

Langley, K., Fowler, T., Ford, T., Thapar, A. K., Van Den Bree, M., Harold, G., … & Thapar, A. (2010). Adolescent clinical outcomes for young people with attention-deficit hyperactivity disorder.  The British Journal of Psychiatry, 196 (3), 235-240.

National Resource Center on ADHD. (2017). About ADHD. CHADD. https://chadd.org/wp-content/uploads/2018/03/aboutADHD.pdf

Sedgwick, J. A., Merwood, A., & Asherson, P. (2019). The positive aspects of attention deficit hyperactivity disorder: a qualitative investigation of successful adults with ADHD. ADHD Attention Deficit and Hyperactivity Disorders11, 241-253.

Volkow, N. D., Wang, G. J., Kollins, S. H., Wigal, T. L., Newcorn, J. H., Telang, F., Fowler, J. S., Zhu, W., Logan, J., Ma, Y., Pradhan, K., Wong, C. & Swanson, J. M. (2009). Evaluating dopamine reward pathway in ADHD: clinical implications.  Jama, 302 (10), 1084-1091.e

Young, S., Adamo, N., Ásgeirsdóttir, B. B., Branney, P., Beckett, M., Colley, W., Cubbin, S. Deeley, Q., Farrag, E., Gudjonsson, G., Hill, P., Hollingdale, J., Kilic, O., Lloyd, T., Mason, P., Paliokosta, E., Perecherla, S., Sedgwick, J., Skirrow, C., Tierney, K., van Rensburg, K. & Woodhouse, E. (2020). Females with ADHD: An expert consensus statement taking a lifespan approach providing guidance for the identification and treatment of attention-deficit/hyperactivity disorder in girls and women.  BMC psychiatry, 20 (1), 1-27.

Saul Mcleod, PhD

BSc (Hons) Psychology, MRes, PhD, University of Manchester

Educator, Researcher

Saul Mcleod, Ph.D., is a qualified psychology teacher with over 18 years experience of working in further and higher education. He has been published in peer-reviewed journals, including the Journal of Clinical Psychology.

Olivia Guy-Evans, MSc

Associate Editor for Simply Psychology

BSc (Hons) Psychology, MSc Psychology of Education

Olivia Guy-Evans is a writer and associate editor for Simply Psychology. She has previously worked in healthcare and educational sectors.