What is ADHD
ADHD is a term that many people are familiar with yet often do not fully understand.
Let us tell you the truth.
Attention Deficit Hyperactivity Disorder
Patients' brain activity differs from ordinary people's, especially in vital areas such as the prefrontal cortex, basal ganglia and cerebellum, which are responsible for executive function.
In addition to the differences in brain activity in essential areas responsible for executive function, studies have shown that ADHD is also related to differences in the neurotransmitters that transmit signals between nerve cells in the brain.
Specifically, there is a lower level of dopamine, norepinephrine, and serotonin in the brains of individuals with ADHD, which can affect attention, motivation, and mood regulation.
These differences in brain structure and function, as well as neurotransmitter activity, suggest that ADHD is a neurological disease that affects how the brain processes and responds to information.
ADHD is a disease related to cranial nerves.
Behavior and Judgment
Structural anomalies or differences in the brain's anatomy are commonly found in the frontal lobe of individuals with ADHD. The frontal lobe is a vital brain region responsible for executive functions, such as decision-making, planning, attention, and problem-solving. Differences in the structure of this area may affect an individual's ability to regulate their behaviour, emotions, and attention, leading to the characteristic symptoms of ADHD. E.g. impulsivity, hyperactivity, and inattention.
Studies have found reduced frontal lobe volume, cortical thickness, and abnormal connectivity in individuals with ADHD compared to those without the disorder. These findings suggest that ADHD is not only related to differences in brain function but also to brain structure.
Primarily affects the brain
The three main symptoms of Attention Deficit Hyperactivity Disorder (ADHD) are inattention, hyperactivity, and impulsivity. Inattention can manifest as difficulty focusing on tasks, forgetfulness, and disorganization. Hyperactivity refers to an excess of physical energy, restlessness, and fidgeting. Impulsivity involves acting without thinking, interrupting others, and making hasty decisions. These symptoms can be present in varying degrees and can cause significant impairment in academic, social, and occupational functioning.
3 types of ADHD
There are three types of ADHD, according to the DSM-5 diagnostic criteria:
Inattentive Type, formerly known as ADD (Attention Deficit Disorder): Individuals with this type of ADHD primarily display symptoms related to inattention, such as difficulty sustaining attention, forgetfulness, and being easily distracted.
Hyperactive-Impulsive Type: Individuals with this type of ADHD primarily display symptoms related to hyperactivity and impulsivity, such as fidgeting, interrupting others, and difficulty sitting still.
Combined Type: Individuals with this type of ADHD display symptoms related to inattention and hyperactivity-impulsivity. It is the most common type of ADHD.
It's important to note that while the subtypes may have different symptom presentations, they have all fallen under the umbrella term ADHD since 2013.
Symptoms of ADHD can have adverse impacts on various aspects of life.
The impact of ADHD on an individual's life can be significant, affecting their self-esteem, relationships, and overall well-being. However, with appropriate treatment and support, individuals with ADHD can learn to manage their symptoms and improve their quality of life.
Causes of ADHD
The causes of ADHD are not yet fully understood, but research suggests that it is a complex interaction between genetic and environmental factors that affect the development and function of the brain.
Studies have shown that ADHD tends to run in families, indicating a genetic component to the disorder. However, no single gene has been found to cause ADHD, and multiple genes are likely involved. Environmental factors, such as prenatal exposure to alcohol, tobacco, certain toxins, premature birth, low birth weight, and brain injuries, have also been associated with an increased risk of developing ADHD.
Additionally, differences in brain structure, function, and neurotransmitter activity have been observed in individuals with ADHD, suggesting that the disorder is also related to underlying neurological factors.
Overall, the exact causes of ADHD are still under investigation, and a combination of genetic, environmental, and neurological factors likely contribute to the development of the disorder.
Comorbidity of ADHD
Comorbidity is the presence of two or more medical or mental health conditions in an individual simultaneously. In the case of ADHD, it is common for individuals with the disorder to have other conditions, such as anxiety, depression, learning disabilities, oppositional defiant disorder, and conduct disorder.
The exact reasons for the high comorbidity rate of ADHD with other conditions are not fully understood. However, research suggests that ADHD may share underlying genetic, environmental, and neural mechanisms. For example, individuals with ADHD may be more vulnerable to anxiety and depression due to their executive function, attention, and social interaction challenges.
It is essential to identify and address comorbid conditions in individuals with ADHD as they can further exacerbate the disorder's symptoms and impact their overall functioning and quality of life. Effective treatment of ADHD may also help improve the symptoms of comorbid conditions and vice versa.
Faraone SV, Biederman J. Neurobiology of attention-deficit hyperactivity disorder. Biol Psychiatry. 1998 Nov 15;44(10):951-8. doi: 10.1016/s0006-3223(98)00240-6. PMID: 9821559.
Cortese S, Castellanos FX. Neuroimaging of attention-deficit/hyperactivity disorder: current neuroscience-informed perspectives for clinicians. Curr Psychiatry Rep. 2012 Oct;14(5):568-78. doi: 10.1007/s11920-012-0310-y. PMID: 22851201; PMCID: PMC3876939.
Centers for Disease Control and Prevention. (2021, August 31). Attention-Deficit / Hyperactivity Disorder (ADHD). Retrieved from https://www.cdc.gov/ncbddd/adhd/facts.html
Centers for Disease Control and Prevention. (2021). Attention-Deficit / Hyperactivity Disorder (ADHD): Symptoms and Diagnosis. Retrieved from https://www.cdc.gov/ncbddd/adhd/diagnosis.html
National Institute of Mental Health. (2021). Attention-Deficit/Hyperactivity Disorder (ADHD). Retrieved from https://www.nimh.nih.gov/health/topics/attention-deficit-hyperactivity-disorder-adhd/index.shtml
American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.).
Harpin VAThe effect of ADHD on the life of an individual, their family, and community from preschool to adult lifeArchives of Disease in Childhood 2005;90:i2-i7.
Faraone, S. V., & Larsson, H. (2019). Genetics of attention deficit hyperactivity disorder. Molecular psychiatry, 24(4), 562–575. https://doi.org/10.1038/s41380-018-0070-0
Salavert, J., Ramos-Quiroga, J. A., Moreno-Alcázar, A., Caseras, X., Palomar, G., Radua, J., Bosch, R., Salvador, R., McKenna, P. J., Casas, M., & Pomarol-Clotet, E. (2018). Functional Imaging Changes in the Medial Prefrontal Cortex in Adult ADHD. Journal of Attention Disorders, 22(7), 679–693. https://doi.org/10.1177/1087054715611492
Shaw P, Eckstrand K, Sharp W, Blumenthal J, Lerch JP, Greenstein D, Clasen L, Evans A, Giedd J, Rapoport JL. Attention-deficit/hyperactivity disorder is characterized by a delay in cortical maturation. Proc Natl Acad Sci U S A. 2007 Dec 4;104(49):19649-54. doi: 10.1073/pnas.0707741104. Epub 2007 Nov 16. PMID: 18024590; PMCID: PMC2148343.
Froehlich TE, Anixt JS, Loe IM, Chirdkiatgumchai V, Kuan L, Gilman RC. Update on environmental risk factors for attention-deficit/hyperactivity disorder. Curr Psychiatry Rep. 2011 Oct;13(5):333-44. doi: 10.1007/s11920-011-0221-3. PMID: 21779823; PMCID: PMC3277258.
Pliszka SR. Comorbidity of attention-deficit/hyperactivity disorder with psychiatric disorder: an overview. J Clin Psychiatry. 1998;59 Suppl 7:50-8. PMID: 9680053.
Nigg JT. Attention-deficit/hyperactivity disorder and adverse health outcomes. Clin Psychol Rev. 2013 Mar;33(2):215-28. doi: 10.1016/j.cpr.2012.11.005. Epub 2012 Dec 7. PMID: 23298633; PMCID: PMC4322430.