Introduction
Most of us have faced moments when we were not able to concentrate on the work on hand. There were times when focusing on a task was a big challenge. However, for most of us this type of syndrome is not very common. However, for some people these types of behaviors are a day-to-day affair. For those people this type of syndrome is uncontrollable and persistent. If a person shows such signs then they may be a victim of attention deficit hypersensitivity syndrome. Attention Deficit Hypersensitivity Syndrome (ADHD) does not show any physical signs or cannot be detected using laboratory tests. The symptoms of ADHD are often same as other physical and psychological disorders. ADHD probably has been around lot longer than we actually realized. ADHD became a well-known disease in USA during 1970s. Since that time US has seem an increase in ADHD patients over the last few decades. Reasons of ADHD are still not well known to the doctors and researchers. This essay will discuss about ADHD in detail, the major causes of the disorder, controversial reasons, future research requirement and treatments options available for ADHD.
What is ADHD?
One of the most common brain disorders found in children is attention deficit hyperactivity disorder (ADHD) which depending on its degree of severity can continue through one's adolescence to even adulthood. Though there is no definite scientific explanation but boys are more likely to be affected by ADHD than girls (NIMH, 2012). Children with ADHD have difficulty staying focused and attentive to anything for long. They also tend to be hyperactive. Children suffering from ADHD are found to be having problem in getting along with other children in school or adults and finishing tasks on time. The overall performance of children gets hugely affected due to ADHD.
Signs and Symptoms
Though normally children are a bit hyperactive, inattentive and impulsive sometimes but with children with ADHD, these symptoms are more severe than others. Children with ADHD can get easily distracted, forget things, miss details and move from one activity to another frequently. They also have trouble focusing on one task for more than few minutes. They have problem finishing their tasks on time and often struggle to follow instructions. They have problem sitting still and are constantly in motion. They are very impatient and can talk nonstop. When children show these symptoms for 6 months or more in a severe manner, only then they are only diagnosed with ADHD (NIMH, 2012).
What Causes ADHD?
There is an array of factors attributed to the cause of ADHD. ADHD is not a medical disorder resulting out of low intelligence, poor motivation or upbringing and laziness. Rather a combination of genetic, environmental and other factors is considered to be the main causative factor for this disorder.
Genetic Reasons
Genetic reasons are an important factor for ADHD. Several studies have indicated that children who have a family history of ADHD are more likely to be affected by this order than general population. Dr. Joseph Biederman along with his colleagues conducted family studies at the Massachusetts General Hospital to find out whether or not ADHD runs in families and their finding showed that more than 25% children with ADHD have first degree family members suffering from the same disorder (Biederman, Faraone, Keenan & Knee, 1990). A family history of ADHD increases the likelihood of having ADHD five times more in children. Psychiatrist Dr. Dennis Cantwell conducted adoption studies on adopted children to find out if hyperactive adopted children resemble their biological parents more closely than their adoptive parents and the research result showed that hyperactive adopted children resembled their biological parents far more closely than their adoptive parents, thereby proving yet again that ADHD is a genetic disorder (MyADHD).
Different researchers around the world in order to find out if ADHD has any genetic basis or not conducted twin studies by studying a group of non-identical and identical twins. Identical twins share the same genetic information whereas the genetic information shared by non-identical twins is different. That is why if ADHD is a hereditary or genetic disorder then identical twins are more likely than non-identical twins to be affected by this disorder. In Australia, Dr. Florence Levy and her colleagues conducted twin studies by studying about 1,938 families with twins and siblings and they came up with the finding that identical twins have 82% concordance rate for ADHD than 38% of the same in non-identical twins (MyADHD).
Although family, adoption and twin studies have strongly reinforced the genetic basic for ADHD, these studies could not specify the genes related to this order. Therefore, different molecular genetic studies have been conducted by many researchers around the world and two dopamine genes have come to the forefront of being associated with ADHD - the dopamine transporter (DAT1) gene and the dopamine receptor D4 (DRD4) gene (Swansona, Kennedyb & Flodmana, 2000). Dopamine is a neurotransmitter that functions like a chemical messenger by passing signals and information in different vital areas of the brain. The specific genes DAT1 and DRD4 alter the dopamine transmission in the neural networks of the brain, resulting in ADHD (Swansona, Kennedyb & Flodmana, 2000).
Environmental Reasons
Scientists have found out that a lot of environmental factors also attribute to the cause of ADHD. Researchers have conducted several studies to find out the correlation between environment and ADHD and have come up with the finding that women who continued smoking tobacco products and consumed alcohol during pregnancy have their children affected by ADHD. Nicotine and alcohol leave sustained damaging effects on the brain tissue of children if they are exposed to these toxics at an early age. The toxic exposure of nicotine and alcohol lead damages the activity of vital nerve cells which produce neurotransmitters in the brain, attributing to the growth of ADHD (Reader's Digest, 2014). Despite the link between maternal smoking and ADHD, a genetic explanation cannot be removed because women suffering from ADHD are more likely to smoke than non-ADHD mothers (Martin, 2007).
Similarly, when lead exposure takes place in the first three years of a child, then a child may develop ADHD as the toxic lead affects the developing brain tissue of the child. Children exposed to lead paint and rusted pipes may develop hyperactivity and short span of attention. Michigan State University conducted a study in 2007 and came up with the finding that children with ADHD had higher levels of lead in their blood (Reader's Digest, 2014). The presence of lead in great amount may damage the process of a developing brain, making it difficult for children to control themselves. If a healthy living environment with no lead and other toxic exposure can be ensured then children may be able to lead a life devoid of ADHD symptoms.
Brain Injury
Brain injury caused by a serious blow to the head, disease, stroke and tumor can also lead to the problems of inattention and poor regulation of motor activity. However, the National Institute of Mental Health (NIMH) disregards brain injury as a serious risk factor for ADHD because a very small portion of children experiences traumatic head injury (Koch, 2014). Professor Heather Keenan along with her team from the University of Utah performed a study by exploring the database of 62,088 children who were registered with the National Health Service in the UK. Of these children, only 2,782 (4.5%) children suffered a traumatic head injury before they completed two years of age and another 1.8% children were found to have sustained burn injury. Of all the children, only 1.5% children between the age range of 2 and 10 years were diagnosed with ADHD (Collingwood, 2009). Their analysis showed that the rate of ADHD is significantly higher among children with severe head injury than non-injured children.
Controversies
There are many reasons deemed to be the attributive factors of ADHD but these reasons have sparked controversy because contrary to the popular notions, none of these reasons has any scientific basis. There is a notion prevalent among many parents that sugar consumption leads to the growth of ADHD, but many research studies conducted over the years have completely discounted this theory. In one study, children were given foods containing either sugar or sugar substitute every alternate day. The children who consumed sugar showed no behavioral symptoms different from the ones who consumed sugar substitute. In another study, all the children were given sugar substitute aspartame aka Nutrasweet but half of those children's mothers were informed that their children received sugar while the remaining half of the mothers were informed that the children received aspartame. The mothers who believed that their children had received sugar were critical of their children rating them as hyperactive (NIMH, 2012). Dr. Wolraich, a practicing pediatrician, therefore concludes that "the overwhelming number of studies have not been able to demonstrate behavior changes due to sugar consumption in children" (Koch, 2014).
Though no scientific evidence is there that food additives are a contributive factor to ADHD, several studies show that some food colorings and preservatives may prove harmful for children making them hyperactive. The food additives considered to trigger hyperactivity in children are sodium benzoate, FD&C Yellow No. 6, D&C Yellow No. 10, FD&C Yellow No. 5 and FD&C Red No.40 (Huxsahl, 2011). The British government has made it mandatory for many food manufacturers to remove artificial food colorings from their products. FDA in USA has made it mandatory for FD&C Yellow No. 5 to be labelled clearly on the package along with other ingredients (Huxsahl, 2011). Since till date there has been no correlation established between food colorings and ADHD, this is one area requiring further research whether or not limiting certain foods would help prevent this hyperactive disorder.
For a long period of time some of the physicians argued that vestibular system in the brain is the main cause of ADHD. They believed that since vestibular system controls the motor functions of our body, it must be the root cause of the problem. However, subsequent research has shown no correlation between vestibular system in the brain and ADHD. For a long time and even today some believe that poor parenting is definitely a cause of ADHD in children. Children who are not treated properly by their parents have more chances of developing ADHD than children who are treated in a better way by their parents (MyADHD). However, there is not research evidence to support that claim also. The only thing known is that the condition of a child with ADHD may worsen if he faces poor parenting. Good parenting can reduce the effects of ADHD but it definitely is not the root cause of the disorder.
Requirement of Future Research
ADHD is a disease not fully understood. There are treatments which can help reduce the effects of ADHD but still the root causes of ADHD are unknown. One of the areas requiring future research is definitely how the brain functions are different for ADHD patients than a normal patient. Already research is underway to map brain responses for ADHD patients under different conditions. Brain imaging will help us better understand the disease. This will also help the doctors and researchers come up with medication which will be able to cure the problem from the root (Martin, 2007). Another area of future research is to understand various types of ADHD. Still it is not very clear if there are different types of ADHDs and if there are how they are different. This research may provide us insight into why some ADHD patients have anxiety issue and depression while others do not, why some children have behavioral disorders and violent sprees (Martin, 2007). Future research is also required in the field of medications for ADHD.
Conclusion
Attention deficit hyperactivity disorder (ADHD) is a problem found in many children and adults across the world. Children with ADHD show some common symptoms of hyperactivity, inattention and difficulty in getting along with others. Though there is no scientific explanation as yet but boys tend to be more affected by ADHD than girls. Over the years, researchers around the world through numerous studies have found out that the main reasons of ADHD are genetic, environmental and brain injury. It has been seen through twin, adoption and molecular genetic studies that the disorder is highly genetical. Other than genetic reasons, there are environmental reasons like early exposure to toxins like nicotine, alcohol and lead attributing to the growth of this disorder among children. Furthermore, serious head injury is also one of the major reasons for ADHD. There are, however, many controversies associated with some of the reasons considered to be the attributive factors of ADHD. Many parents believe that excessive sugar consumption causes ADHD in children but several studies have shown that there is no link between sugar consumption and hyperactivity. Many others believed that television and bad parenting cause ADHD which again have been discounted by the researchers as completely baseless. There are many who believe that food additives and colorings cause ADHD but no scientific basis has been established till date. There are many areas in ADHD requiring further research. Some of the areas in requirement of more research include how brain functions of an ADHD patient is different from that of a normal child, the various types of ADHD and the medications used for the treatment of this disorder. Since ADHD is a disorder discovered by physicians not many years ago, there are a lot of things still unknown about it and only more in-depth future studies and research will bring about an explanation for the questions still unanswered.
References
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Biederman, J., Faraone, S. V., Keenan, K., Knee, E., et al. (1990). Family-genetic and psychosocial risk factors in DSM-III attention deficit disorder. Journal of the American Academy of Child and Adolescent Psychiatry, 29, 526-533. Retrieved on 11th January 2014 from <http://www.ncbi.nlm.nih.gov/pubmed/2387786>
MyADHD. Causes of ADHD. Retrieved on 11th January 2014 from <http://www.myadhd.com/causesofadhd.html>
Swansona, J.M., Kennedyb, J., Flodmana, P., et al. (2000). Dopamine Genes and ADHD. Science Direct. Retrieved on 11th January 2014 from <http://www.sciencedirect.com/science/article/pii/S0149763499000627>
Reader's Digest. (2014). Can Environmental Factors Cause ADHD. Retrieved on 11th January 2014 from <http://www.rd.com/health/conditions/can-environmental-factors-cause-adhd/>
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Collingwood, J. (2009). ADHD and Head Injury Link Examined. Psych Central. Retrieved on 11th January 2014 from <http://psychcentral.com/lib/adhd-and-head-injury-link-examined/0001574>
Koch, Kristin. (2014). What Causes ADHD? 12 Myths and Facts. Health Media Ventures Inc. Retrieved on 11th January 2014 from <http://www.health.com/health/gallery/0,,20441463,00.html>
Huxsahl, J. E. (2011). What does the research say about the relationship between food additives and ADHD?. Mayo Clinic. Retrieved on 11th January 2014 from <http://www.mayoclinic.org/diseases-conditions/adhd/expert-answers/adhd/FAQ-20058203>
