Introduction:
Certain disorders may affect neurological development, impairing the brain's proper functioning. This may result in various social, psychological, and cognitive neurodevelopmental disorders. One such neurodevelopmental disorder is ADHD, also known as attention-deficit/ hyperactivity disorder.
What Is Attention Deficit Hyperactive Disorder?
Attention deficit hyperactivity disorder, also known as ADHD, is a psychological neurodevelopmental disorder most commonly affecting children and adults. It is a persistent crippling condition that affects the child psychologically, physically, and emotionally. It is characterized by difficulty controlling attention, lack of self-control, and hyperactive and impulsive nature. As a result, children tend to get easily distracted and are at increased risk for adverse social, psychological, and educational outcomes.
Several studies indicate a steady rise in cases diagnosed with ADHD, considering the increasing awareness among parents. It is also widely prevalent among teenagers and adults. However, with the rising social media fad, it is essential to eliminate false positives and negate the social stigma associated with ADHD, as it may prove even more detrimental to the affected child.
What Are the Causes of ADHD?
Though science has reached the peak of advancements, the cause of ADHD remains debatable. Various studies and research elucidate genetics to be the prime cause of ADHD. The risk factors associated with ADHD are:
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Positive family history.
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Substance abuse, consuming alcohol, or smoking during pregnancy.
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Premature baby and low birth weight.
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Exposure to environmental toxins and chemicals.
What Are the Clinical Manifestations of ADHD?
ADHD can be recognized as early as three years of age, though many a time, symptoms may manifest later during childhood or even as an adult. It is more prevalent in boys. It may range in severity from mild to severe. Identifying the subtle signs in kids can help diagnose the condition early and significantly improve the quality of life. The signs and symptoms can be categorized as below:
Predominantly Inattentive:
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Trouble staying focused.
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Inattentive or easily distracted.
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Tends to daydream.
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Has trouble listening even when spoken to directly.
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Loses things frequently.
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Has trouble sitting still.
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Has difficulty doing organized chores.
Predominantly Hyperactive or Impulsive:
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Cannot stay or sit still.
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Hyperactive.
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Excessive talking.
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Bouncing, jumping, running, or climbing.
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Always interrupts others.
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Always on the go mode.
Adults:
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Low self-esteem.
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Anger or rage issues.
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Substance abuse, smoking, or alcohol.
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Difficulty in concentrating.
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Easily bored.
Certain kids might exhibit both inattentive and hyperactive behavior. However, poor attention span and hyperactiveness are normal traits of many children. They have trouble concentrating on one activity or sticking to the same routine for a long. They are also energetic and love to explore different zones with zeal and enthusiasm. Such kids should be labeled as having ADHD. Understanding the child’s behavior thoroughly and recognizing their social, psychological, and developmental milestones is imperative before evaluating them for ADHD.
How Significant Is It to Diagnose ADHD?
Early diagnosing and prompt management are essential to help children tackle ADHD. Children with ADHD encounter various problems in life, from difficulty in coping with their studies, being judged by society, strained peer relationships, and overall negative and hostile behavior resulting in low self-esteem. Though ADHD cannot be cured completely, appropriate medical and behavioral therapies can bring promising outcomes, helping the child lead a normal, happy life. Therefore, to guarantee successful treatment, identifying the condition is essential.
However, diagnosing ADHD is not as simple as a blood test or an X-ray. Also, it is not a one-step diagnosis. Instead, it requires a series of physical and medical examinations to confirm ADHD.
How to Diagnose ADHD?
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History - A detailed medical and family history should be elicited to assess if any other family member or sibling is diagnosed with ADHD.
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Physical Examination - Assessing the child’s vision, hearing, and other developmental skills (motor and verbal) can be helpful screening tests. Assessing the child’s intelligence, behavioral pattern, aptitude, and other personal traits can prove valuable. Doctors may take some input from the parents or school teachers while performing the physical examination.
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Scoring Systems - The American Psychiatric Association and the Conners scale are frequently used assessment tools for ADHD.
What Is the Role of Neuroimaging in Diagnosing ADHD?
Several studies believe rating scales and physical examinations are unreliable in diagnosing ADHD. Therefore, considering the need for a more objective, reliable, and conclusive diagnostic tool for ADHD, studies progressed toward neuroimaging. Neuroimaging refers to various brain scanning techniques that help understand neurological functioning and morphology. This helps with real-time imaging to understand the source of the neuronal activity, conduction of electrical impulses between the nerves, and the blood flow within the brain.
Various imaging techniques used in ADHD are
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Neuropsychiatric EEG-Based Assessment Aid System - This is a brain scan that computes the theta and beta brain waves. These wave ratios are found to be higher in kids with ADHD when compared to others.
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Functional MRI (fMRI) - A functional MRI helps determine brain activity by assessing the blood flow throughout the brain. It is one of the most popular tests used in diagnosing ADHD.
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Functional brain scans have shown that certain parts of the brain responsible for controlling actions and attention are less active in people with ADHD. Observations from functional neuroimaging have highlighted activity in the frontal and parietal networks responsible for action execution and attention regulation. This underactivity contributes to attention deficits and hyperactivity. Moreover, overactivity has been noted in the visual and dorsal attention networks alongside the default mode network. This suggests there might be changes in how these brain networks work in people with ADHD.
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Positron Emission Computed Tomography (PET) Scan - PET scan uses a radioactive isotope that is injected intravenously. This radiotracer is a glucose analog and hence has an increased uptake in intensely active areas such as the brain. PET scan helps evaluate the blood flow and brain activity concomitantly.
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Single-Photon Emission Computed Tomography (SPECT) - SPECT is also a radiotracer study; however, its sensitivity is still debatable.
What Are the Imaging Clues Detected During Brain Imaging for ADHD?
Observations from imaging studies reveal various structural irregularities in the brains of individuals diagnosed with ADHD. These include diminished gray matter density, anomalies in white matter structure, decreased overall brain volume compared to normal levels, decreased size in certain brain regions, delayed cortical maturation persisting into adulthood, and diminished cortical thickness, particularly in the network associated with sustained attention.
What Are the Drawbacks of Brain Scan?
The neurodevelopmental functions in ADHD are compromised to a certain extent as the children tend to have delayed brain maturation when compared to others, and also, the delay is most prominent in the frontal lobe, which is responsible for behavior, attention, and concentration. However, brain scans have certain limitations that hinder their usage in assessing neurodevelopmental functions entirely. They are
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Lack of sensitivity and specificity
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Lack of standardization.
Conclusion:
Further research and proper standardization protocols can help understand the role of neuroimaging in diagnosing ADHD. It may also prove valuable in designing a dedicated treatment protocol, facilitating their applications widely in clinical settings
