Attention deficit hyperactivity disorder (ADHD)

Last updated date: 13-Jun-2023

Originally Written in English

Attention deficit hyperactivity disorder (ADHD)


Attention Deficit Hyperactivity Disorder (ADHD) is a psychiatric disorder that has long been recognized as having an impact on children's capacity to function. Individuals with this disease exhibit tendencies of inattentiveness, hyperactivity, or impulsivity that are developmentally inappropriate. 

Although there were formerly two diagnoses of Attention Deficit Condition and Attention Deficit Hyperactivity Disorder, the DSM IV unified these into a single disorder with three subtypes: mainly inattentive, predominantly hyperactive, or combination type.

Symptoms frequently appear at an early age and include a lack of attention, loss of focus, disorganization, trouble finishing chores, forgetfulness, and losing items. To be diagnosed as 'ADHD,' these symptoms must be present before the age of 12, endure six months, and interfere with everyday living activities. This must be present in several settings (i.e., at home and school, or school and after-school activities). It can have serious repercussions, such as decreased social contacts, increased hazardous conduct, job loss, and trouble obtaining academic success.

ADHD must be assessed in the context of a person's developmental and cultural appropriateness. It is thought to be an executive functioning disorder, primarily a frontal lobe activity. As a result, people with ADHD demonstrate impairment not just in attention and focus, but also in decision making and emotional control. Children with ADHD may struggle with social connections, be quickly frustrated, and be impulsive. They are frequently referred to as "troublemakers."

ADHD is not a new condition, and it has been known by several names throughout history. In the 1930s, it was characterized as'minimal brain malfunction,' but it has since been renamed ADD and ADHD, respectively. Its incidence has risen through time, with a possible peak in the 1950s as children's education grew more standardized.

It is critical to detect and treat the problem as early as possible so that the symptoms do not remain into adulthood and develop additional concomitant disorders. Stimulants and psychotherapy are commonly used to treat the disease. 


Epidemiology of ADHD

Epidemiology of ADHD

When diagnosed using the DSM-IV criteria, ADHD is expected to affect around 6–7 % of persons aged 18 and under. Rates in this age range are expected to be about 1–2 % when diagnosed using ICD-10 criteria. Children in North America tend to have a higher prevalence of ADHD than children in Africa and the Middle East; this is thought to be owing to differences in diagnosis procedures rather than a difference in underlying frequency. 

When the same diagnostic procedures are employed, the rates in different nations are comparable. ADHD is diagnosed almost three times more frequently in boys than in girls. This might be due to an actual difference in the underlying rate, or to the fact that women and girls with ADHD are less likely to be diagnosed.

Since the 1970s, rates of diagnosis and treatment have risen in both the United Kingdom and the United States. Prior to 1970, it was uncommon for children to be diagnosed with ADHD, but by the 1970s, rates were about 1%. This is thought to be related to changes in how the disorder is identified and how readily individuals are ready to treat it with pharmaceuticals, rather than an actual shift in the condition's prevalence.

Changes to the diagnostic criteria with the introduction of the DSM-5 in 2013 are expected to increase the number of persons diagnosed with ADHD, particularly among adults.

Many non-caucasian children go untreated and unmedicated as a result of differences in the treatment and understanding of ADHD between caucasian and non-caucasian communities. It was discovered that there was frequently a gap between caucasian and non-caucasian understandings of ADHD in the United States. This resulted in a divergence in the categorization of ADHD symptoms, and therefore its misdiagnosis. It was also shown that non-Caucasian family and instructors commonly interpreted ADHD signs as behavioral concerns rather than mental disease. 


What are the possible underlying causes of ADHD?

ADHD cause

ADHD's etiology is linked to a number of variables, including both a hereditary and an environmental component. In terms of psychiatric disorders, it is one of the most heritable conditions. Monozygotic twins have substantially higher concordance than dizygotic twins. Siblings are twice as likely as the overall population to develop ADHD.

Similarly, viral infections, smoking during pregnancy, nutritional inadequacy, and fetal alcohol exposure have all been investigated as potential causes of the condition. There are no consistent findings on brain imaging of ADHD individuals. The amount of dopaminergic receptors has also been linked to the development of the illness, with studies showing that the receptors are reduced in the frontal lobes of those with ADHD. There is also evidence that noradrenergic receptors have a function in ADHD.


Pathophysiology of ADHD


ADHD Pathophysiology

ADHD is linked with cognitive and functional problems that are related to generalized brain abnormalities. Individuals suffering from ADHD have tiny anterior cingulate gyrus and dorsolateral prefrontal cortex (DLFPC). These alterations are assumed to account for the deficiencies in goal-directed behavior.

Furthermore, as evaluated by fMRI, activity in the frontostriatal area is lower in these people. It is critical to comprehend these pathophysiological processes so that medication may be targeted at them. It is critical to understand that ADHD is a clinical diagnosis. There are no standard laboratory or imaging results in ADHD patients.


History and physical examination findings in those with ADHD

ADHD physical examination

It is critical to have a thorough history of the individual in question in order to properly diagnose ADHD. ADHD is diagnosed in children based on their history, where the children struggle with at least six of the nine symptoms listed in the DSM 5.

Inattentive symptoms include: not paying close attention to tasks, missing small details, rushing through tasks, not seeming to listen when spoken to, difficulty organizing things, not finishing work, dislikes or avoids tasks that take sustained mental effort, losing thins, or being forgetful. 

Hyperactive symptoms include: fidgeting, feeling like an "internal motor" is always going, leaving their seat, climbing on things, being loud, blurting out answers, talking excessively or out of turn, having trouble waiting their turn, interrupts, or intrudes on others. These symptoms must be present in multiple settings.

ADHD impairs functioning and growth. This can include individuals who do not work and is sometimes overlooked in this demographic. A stay-at-home mom, for example, may find it difficult to send her children to school on time, organize her home, pay attention while driving, and so on, which impacts her functioning and everyday life even when she is not at work or school. When establishing a diagnosis, it is critical to keep this in mind.


How are children with ADHD evaluated?

ADHD Evaluation

ADHD is a clinically diagnosed condition that does not have any particular laboratory or radiologic diagnostics. Because neuropsychological tests are not as sensitive in detecting the condition, the disorder should be diagnosed based on the patient's history. The patient with ADHD is often evaluated using several rating scales and many informants, which may include teachers and parents. A doctor must explore for other diseases that may be causing the symptoms that a kid is showing. It should not be diagnosed in the presence of symptoms from another condition, such as a psychotic or manic episode.

By using DSM 5, ADHD can be classified into three categories as follows:

1. Predominantly inattentive:

In children, 6 or more of the following symptoms, and 5 or more in adults, excluding circumstances where these symptoms are better explained by another mental or medical condition:

  • Frequently overlooks details or making careless mistakes.
  • Often has difficulty maintaining focus on one task or play activity.
  • Often appears not to be listening when spoken to, including when there is no obvious distraction.
  • Frequently does not finish following instructions, failing to complete tasks.
  • Often struggles to organise tasks and activities, to meet deadlines, and to keep belongings in order.
  • Is frequently reluctant to engage in tasks which require sustained attention.
  • Frequently loses items, including those required for tasks.
  • Is frequently easily distracted by irrelevant things, including thoughts in adults and teenagers.
  • Often forgets daily activities, or is forgetful while completing them.


2. Predominantly impulsive or hyperactive:

6 or more of the following symptoms in children, and 5 or more in adults, excluding cases where these symptoms are explained better by another mental or physical condition:

  • Is often fidgeting or squirming in seat.
  • Frequently has trouble sitting still during dinner, homework, at work, etc.
  • Frequently runs around in inappropriate situations. In adults and teenagers, this may be present as restlessness.
  • Often cannot quietly engage in leisure activities or play.
  • Frequently seems to be in constant motion, or uncomfortable when not in motion.
  • Often talks too much.
  • Often answers a question before it is finished, or finishes people's sentences.
  • Often struggles to wait his or her turn, including waiting in lines.
  • Frequently interrupts or intrudes, including into others' conversations or activities, or by using people's things without asking.


3. Combination of the above:

  • Meet the criteria for both inattentive and hyperactive-impulsive ADHD.


Treatment of ADHD

ADHD Treatment

ADHD is normally managed with therapy or medication, either alone or in combination. While therapy may improve long-term results, it does not completely eliminate unfavorable effects. Stimulants, atomoxetine, alpha-2 adrenergic receptor agonists, and antidepressants are among the medications utilized.

A substantial quantity of positive reinforcement increases task performance in people who have difficulty focusing on long-term rewards. ADHD medications also increase children's perseverance and task performance.


Behavioural therapies

There is strong evidence to support the use of behavioural therapy in the treatment of ADHD. They are the first-line therapy for patients with mild symptoms or children under the age of six. Psychoeducational input, behaviour therapy, cognitive behavioural therapy, interpersonal psychotherapy, family therapy, school-based treatments, social skills training, behavioural peer intervention, organization training, and parent management training are some of the psychological therapies employed. 

Although neuro-feedback has been utilized, it is uncertain if it is effective. Parent training may help with a variety of behavioural issues, including oppositional and non-compliant conduct.

There is minimal high-quality research on the effectiveness of family therapy for ADHD, but the available data suggests that it is comparable to community care and better than placebo. ADHD-specific support groups can give knowledge and may assist families in dealing with ADHD.

Social skills training, behavioral modification, and medication may have some limited positive impacts in peer relationships. The establishment of connections with non-deviant peers is the most essential element in decreasing eventual psychological difficulties, such as serious depression, crime, school failure, and substance use disorders.



  • Stimulants:

The most effective pharmacological therapy is stimulant medicines. They relieve symptoms in 80 percent of persons, but the relief is not long-lasting if the medicine is stopped. According to teachers and parents, methylphenidate appears to ease symptoms. Stimulants may also lower the incidence of unintended accidents in ADHD youngsters.

 According to magnetic resonance imaging studies, long-term therapy with amphetamine or methylphenidate reduces anomalies in brain structure and function seen in ADHD patients. A 2018 study discovered that methylphenidate had the highest short-term benefit in youngsters while amphetamines had the best long-term benefit in adults.

The long-term effects of ADHD drugs have yet to be completely identified, however stimulants are typically useful and safe for children and adolescents for up to two years. However, there are certain drawbacks and contraindications to using them. Stimulant psychosis and mania are extremely uncommon at therapeutic levels, occurring in just around 0.1 percent of people within the first few weeks of initiating amphetamine medication. 

Chronic severe stimulant misuse over months or years might induce these symptoms, however antipsychotic treatment has been shown to effectively alleviate the symptoms of acute amphetamine psychosis.

Long-term therapy patients should be monitored on a regular basis. There are evidence that stimulant therapy for children and adolescents should be discontinued on a regular basis to monitor the continued need for medicine, prevent potential growth delays, and lessen tolerance. Long-term abuse of stimulant drugs at doses above the therapeutic range for ADHD therapy has been linked to addiction and dependency.

Untreated ADHD, on the other hand, is linked to an increased risk of drug use disorders and behavioural issues. The use of stimulants appears to either lessen or have no effect on these risks. Because of the negative effects of untreated ADHD, several guidelines have concluded that the risks of not treating severe ADHD are greater than the hazards of medication, regardless of age. 


  • Non-stimulants:

There are a number of non-stimulant medications, such as Viloxazine, atomoxetine, bupropion, guanfacine, and clonidine, that may be used as alternatives, or added to stimulant therapy. There are no good studies comparing the various medications; however, they appear more or less equal with respect to side effects. 

For children, stimulants appear to improve academic performance while atomoxetine does not. Atomoxetine, due to its lack of addiction liability, may be preferred in those who are at risk of recreational or compulsive stimulant use. Evidence supports its ability to improve symptoms when compared to placebo. There is little evidence on the effects of medication on social behaviors. Antipsychotics may also be used to treat aggression in ADHD.


Other methods of treatment

Regular physical activity, particularly aerobic exercise, is an effective adjunct treatment for ADHD in both children and adults, especially when taken with stimulant medication (although the best intensity and type of aerobic exercise for improving symptoms are not currently known).

Swimming instruction, for example, was found to enhance cognition, coordination, and mental health in children with ADHD in one research. Regular aerobic exercise has been shown to increase executive functioning (including attention, inhibitory control, and planning, among other cognitive domains) in ADHD patients, as well as quicker information processing speed and memory.

Parent-teacher ratings of behavioral and socio-emotional outcomes in response to regular aerobic exercise include: improved overall function, decreased ADHD symptoms, improved self-esteem, decreased anxiety and depression, fewer somatic complaints, improved academic and classroom behavior, and improved social behavior. Exercising while on stimulant medication enhances the stimulant drug's effect on executive function. These short-term benefits of exercise are thought to be mediated by an increase in synaptic dopamine and norepinephrine in the brain.

Dietary modifications are not suggested by the American Academy of Pediatrics, the National Institute for Health and Care Excellence, or the Agency for Healthcare Research and Quality as of 2019. According to a 2013 meta-analysis, free fatty acid supplementation or reduced consumption of artificial food coloring improves symptoms in fewer than a third of children with ADHD. These advantages may be restricted to children with dietary allergies or those who are taking ADHD medication at the same time.

Chronic iron, magnesium, and iodine deficiency may have a deleterious influence on ADHD symptoms. There is some evidence that reduced tissue zinc levels may be related to ADHD. Zinc supplementation is not advised as a therapy for ADHD in the absence of a proven zinc deficiency (which is uncommon outside of impoverished countries). When used with amphetamine for the treatment of ADHD, zinc supplementation may lower the lowest effective dosage of amphetamine.


Does ADHD have a good outcome?

ADHD good outcome

In around 30–50% of instances, ADHD continues throughout adulthood. Those afflicted are likely to acquire coping techniques as they age, somewhat compensating for their prior symptoms. Children with ADHD are more likely to have unintended injury. Medication has been found to have effects on functional impairment and quality of life (e.g., reduced risk of accidents) across several domains. Smoking rates among persons with ADHD are around 40% higher than in the general population.



Attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is a behavioral and neurodevelopmental condition characterized by pervasive, debilitating, and otherwise age-inappropriate inattention, hyperactivity, and impulsivity. Some people with ADHD have trouble managing their emotions or have executive function issues.

The symptoms must be present for more than six months and create issues in at least two situations in order to be diagnosed (such as school, home, work, or recreational activities). Problems paying attention in childhood can lead to poor academic achievement.

It is also linked to other mental illnesses and substance abuse problems. Despite the fact that it causes damage, especially in modern society, many persons with ADHD exhibit sustained attention for things that they find engaging or gratifying, a condition known as hyperfocus.

In the vast majority of instances, the particular reason or causes remain unknown. It is believed that genetic factors account for around 75% of the risk. Toxins and infections during pregnancy, as well as brain impairment, are potential environmental hazards. It does not appear to be tied to parenting or disciplinary style. It affects around 5–7% of children when diagnosed using the DSM-IV criteria and 1–2% of children when diagnosed using the ICD-10 criteria.

ADHD management guidelines differ by country, but often include a combination of drugs, therapy, and lifestyle modifications. The British guideline emphasizes environmental changes and ADHD education for individuals and caregivers as the first line of defense. If symptoms continue, age-appropriate parent-training, medication, or psychotherapy (particularly cognitive behavioral therapy) may be considered.