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ADHD: Types, Causes, Symptoms, Treatment, and More

ADHD affects millions of children and adults throughout the world. Studies suggest that the prevalence of ADHD has increased by approximately 42 percent in children between 2003 and 2011 (1, 2).

What is ADHD?

ADHD, or Attention Deficit Hyperactivity Disorder, is a neurodevelopmental disorder characterized by significant difficulties with attention, impulsivity, and/or hyperactivity.

Although it is frequently recognized in childhood, with symptoms usually appearing between ages 3 to 6, diagnosis is possible at any age, including in adults. Males are diagnosed more frequently than females, with a prevalence three times higher (3, 4).

ADHD may impact various aspects of life, including career success, relationships, and family dynamics (5).

Undiagnosed ADHD in children might lead to challenges in adulthood, such as the potential use of alcohol or drugs as coping mechanisms (6).

Anxiety or mood disorders are also more common in individuals with ADHD (7).

Individuals with ADHD typically face difficulties in maintaining focus on a single task for extended durations and susceptibility to internal and external distractions. Additionally, they may encounter difficulties with self-control in various situations.

Parents who have children with ADHD may face difficulties surrounding homework and managing behavior (8).

Types of ADHD

There are three types of ADHD as recognized in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition Text Revision(DSM-5-TR).

  • Attention-Deficit/Hyperactivity Disorder, Predominantly Inattentive Type: This type primarily involves difficulties with focus and attention.
  • Attention-Deficit/Hyperactivity Disorder, Predominantly Hyperactive-Impulsive Type: This type primarily involves hyperactive and impulsive behaviors.
  • Attention-Deficit/Hyperactivity Disorder, Combined Type: This type includes symptoms of inattention, hyperactivity, and impulsivity.

Signs and Symptoms of ADHD

ADHD symptoms can vary depending on the type and differ between children and adults. It’s important to recognize that behavioral disorders like ADHD can impact self-esteem, potentially leading to anxiety or depression.

Common Symptoms of ADHD

  • Difficulty Concentrating or Focusing: Challenges in concentrating on a single task for extended periods.
  • Easily Distracted: Being prone to distraction is a hallmark symptom for both children and adults with ADHD.
  • Forgetfulness: This often applies to daily tasks and responsibilities.
  • Trouble Sitting Still: Experiencing restlessness and a constant need to move.
  • Interrupting People While Talking: Frequently talking over others or interrupting.

Symptoms More Common in Boys

  • Acting out
  • Talking excessively
  • Interuppting others

Symptoms More Common in Girls

  • Low self-esteem 
  • Anxiety
  • Tendency to daydream
  • Inattention

Note on Gender and ADHD Symptoms: While this article references symptoms observed commonly in boys and girls, it’s important to recognize that ADHD symptoms can vary widely and are not limited to binary gender categories. Individuals of all gender identities may experience ADHD differently, and these categorizations are based on general trends rather than strict rules.

Symptoms of Inattentive ADHD in Children

  • Difficulty focusing on school tasks: Struggling with academic performance.
  • Difficulty listening: Not responding when spoken to directly.
  • Inability to complete chores: Failing to finish assigned tasks.
  • Disorganization: Challenges with keeping their room in order.
  • Losing items: Losing or misplacing objects.
  • Distractability: Becoming distracted by things in their environment

Symptoms of Hyperactive/Impulsive ADHD

  • Feels driven by a motor: always”on-the-go” demeanor.
  • Fidgeting: Tapping their hands and feet
  • Difficulty staying seated: Squiring in their seat
  • Excessive talkativeness: Being overly chatty and unable to stay quiet.
  • Running/Climbing excessively: Running or climbing in unsuitable situations.
  • Difficulty with quiet play: Struggling to engage in calm and quiet activities.
  • Challenges with waiting his/her turn: Difficulty waiting for their turn in activities or conversations.

These symptoms can manifest differently in individuals, and the presence of one or more symptoms does not necessarily indicate a diagnosis of ADHD.

A healthcare professional should be consulted for an accurate diagnosis and appropriate treatment plan.

Adult ADHD

The majority of children, around 60 percent, who are diagnosed with ADHD, carry the condition into adulthood. (9). However, some studies have found that the severity of the disorder lessens with age (10). It is crucial to seek treatment because ADHD can affect many areas of everyday life, such as  friendships, relationships, career, and much more (11).

See if any of these adult signs and symptoms sound familiar to you.

Signs and Symptoms of Adult ADHD

  • Disorganization: Struggling with organization is a common symptom in adults with ADHD.
  • Issues with Time Management: Challenges such as frequent tardiness or procrastination.
  • Impulsivity: Acting without considering the consequences, especially in important situations.
  • Forgetfulness(12): Forgetting important appointments or meetings.
  • Hyperfocus or Lack of Focus: Periods of intense focus or difficulty maintaining focus.
  • Anxiety: Anxiety in adults with ADHD might manifest as restlessness or an inability to relax (13).
  • Lack of Motivation: Feeling unmotivated is a common experience among both children and adults with ADHD.
  • Substance Misuse: Some adults with ADHD might misuse substances as a way to manage symptoms (14).
  • Relationship Concerns: Challenges in maintaining relationships due to symptoms like inattention.

In both adults and children, symptoms can make it difficult to carry out everyday tasks. Be sure to speak to your doctor if you experience several of these symptoms.

What causes ADHD?

The exact causes of ADHD remain largely unknown, with ongoing research exploring various potential factors. Notably, there has been an increase in ADHD diagnoses from 2003 to 2011 (15), (16). This trend has prompted diverse theories and investigations. ADHD is prevalent in the United States, affecting about 5% of children, a rate that aligns with global trends.

While some have proposed that ADHD could be a predominantly American concern, evidence suggests that children worldwide are affected, albeit with varying diagnosis rates. For example, countries like Iceland, Australia, Italy, and Sweden report different prevalence rates (17). Within the United States, there is also significant variation among states; for instance, Nevada reports the lowest rate at 4.2%, while Kentucky has the highest at 14.8% (18).

Potential Causes & Risk Factors of ADHD

While the factors listed below have been associated with an increased risk of developing ADHD, they do not definitively cause the disorder. ADHD is a complex condition, influenced by a combination of genetic, environmental, and neurobiological factors.

  • Excess Sugar Consumption & Lack of Balanced Diet: While some studies (19 have explored correlations between diet and ADHD symptoms, the evidence is not conclusive enough to establish a direct causal relationship. Diet can affect overall health, which may impact behavior and symptoms associated with ADHD, but it is not considered a direct cause of the disorder.
  • Environmental Factors: Various environmental factors, such as prenatal exposure to toxins, have been studied for their potential link to ADHD. These factors may contribute to the risk but are not sole causes of ADHD (20).
  • Cigarette Smoking and Alcohol Consumption During Pregnancy: There is evidence suggesting that smoking and alcohol use during pregnancy can increase the risk of ADHD in offspring. These factors can affect fetal development and are considered significant risk factors (21, 22).
  • Food Coloring, Additives, and Artificial Preservatives in Food: Some studies (23) have suggested a possible link between certain food additives and increased hyperactivity in children. However, this area of research is still subject to debate, and no definitive causal relationship has been established.
  • Neurophysiology or Genetics: ADHD has a strong genetic component, and research has shown that variations in certain genes may increase the risk (24, 25). Neurophysiological factors, such as differences in brain structure and function, have also been observed in individuals with ADHD (26).
  • Certain Drugs During Pregnancy: Exposure to certain substances, such as nicotine or cocaine, during pregnancy is associated with a higher risk of ADHD in children. These substances can have detrimental effects on fetal brain development (21.
  • Chronic Exposure to Lead: Lead exposure, especially in early childhood, has been linked to a range of developmental problems, including a higher risk of ADHD. Lead is a known neurotoxin that can affect brain development (27).
  • Lack of Early Attachment to Parent or Caregiver: Early childhood experiences, including attachment issues, can impact development (28). While such experiences might influence behavior and emotional regulation, they are not considered direct causes of ADHD.

The understanding of ADHD continues to evolve as more research is conducted. These potential causes highlight the complexity of the disorder and the variety of factors that may contribute to its development. If you suspect you or your child may have ADHD, it’s essential to consult with a healthcare professional for a comprehensive evaluation and appropriate guidance.

Note: While these factors are associated with an increased risk of ADHD, they do not individually or collectively account for all cases of ADHD. The disorder is complex, and its development is influenced by a combination of genetic, environmental, and neurobiological factors.

Treatment for ADHD

Various treatment options are available for ADHD including medications, psychotherapy and behavioral therapies. It is important to explore different approaches with your healthcare provider to find the most effective treatment that is tailored to the unique needs of each individual.

ADHD Medications

Both stimulants and non-stimulants are commonly used in treating ADHD.

Central Nervous System (CNS) stimulants which increase dopamine and norepinephrine levels in the brain, are frequently prescribed. These include medications include but are not limited to methylphenidate (example: Ritalin and Concerta) and amphetamine-based stimulants (example: Adderall).

Non-stimulant medications, such as atomoxetine (Strattera), offer an alternative to stimulants.  Non-stimulant medications, which increase norepinephrine levels, are generally considered less likely to be addictive compared to stimulants (29).

Bupropion, an antidepressant, is also used in treating adults with ADHD, particularly if they have co-existing conditions like depression or substance use disorders.

Summary: Both stimulant and non-stimulant medications are used to treat ADHD.

Natural Approaches for ADHD

A holistic approach incorporating a balanced diet, regular exercise, adequate sleep, and limited screen time can support ADHD management (30). Engaging in activities like tai chi (31), yoga, and outdoor time can enhance well-being leading to calmness and reduced hyperactivity.

Dietary modifications, including avoiding certain food additives and allergens, might help alleviate ADHD symptoms (32, 19). Education about ADHD and lifestyle changes such as reducing alcohol and drug use can also be beneficial.

Psychotherapy can be instrumental in addressing self-esteem issues, substance abuse, or family trauma related to ADHD. Traditional therapy may assist with anger management and social skills, while support groups or family therapy can be beneficial for those impacted by a family member’s ADHD.

Positive parenting, appropriate school support, and counseling can aid children with ADHD and their families.

Summary: Natural approaches for ADHD include eating a balanced diet, regular exercise, improving sleep, psychotherapy, psychoeducation, lifestyle changes and having a good support system.

ADHD Diagnosis

ADHD shares symptoms with other neurological disorders and mental health conditions. Anxiety, depression, and unresolved family or educational challenges can mimic ADHD symptoms.

ADHD diagnosis involves a comprehensive assessment. It is based on interview and observations of behavior in different settings like school and home. Not all individuals exhibiting hyperactivity, impulsivity, or inattentiveness necessarily have ADHD.
A thorough evaluation by a healthcare professional is essential for proper diagnosis.

This may include:

  • Interviews with family members, friends, and others who can provide insights into the individual’s behavior.
  • Evaluating lifestyle factors and behavior.
  • Assessing the age of onset and whether symptoms were present in childhood.
  • Screening for neurological disorders and other psychiatric conditions such as depression or anxiety.
  • Performing cognitive testing

A licensed professional may conduct a detailed assessment, gathering information from various sources including school and caregivers. For a diagnosis, symptoms must be evident across multiple settings.

Understanding Diversity in ADHD Diagnosis

ADHD affects children of all ethnicities, with varying prevalence rates among different groups (33). Across all racial-ethnic groups, males had higher ADHD prevalence than females (33).

It’s important to recognize that these statistics can be influenced by a variety of factors, including cultural differences in seeking healthcare, diagnostic practices, and access to medical services. Additionally, gender differences in diagnosis may be influenced by societal expectations and biases in recognizing symptoms.

ADHD is a complex condition that affects individuals of all ethnicities and genders, and its diagnosis and management should be approached with an understanding of these diverse factors.


ADHD is a significant neurodevelopmental disorder impacting development and functioning in daily life.  Each individual with ADHD has unique strengths and challenges. When symptoms start to significantly impact life, seeking a professional evaluation is important. Having support from families, teachers, and caregivers is also essential for children with ADHD. Researching and utilizing the best available resources is key to managing ADHD effectively. With the right treatment, resources and support, individuals with ADHD can lead successfull and fulfilling lives.