The Effects of Methylphenidate on Adults with ADHD

The purpose of this research paper is to gain more information and knowledge regarding ADHD and why Methylphenidate is the number one drug prescribed to treat its symptoms. The following information is from different researches and meta-analysis studying the effects of Methylphenidate on adults. Studies show how Methylphenidate improves the performance in many different aspects of the adult life. These following studies will explain how Methylphenidate decreases the symptoms of ADHD.

Attention-Deficit/Hyperactivity Disorder or A.D.H.D. is a neural development disorder that affects the human brain. You might have heard some people call it ADD, but ADHD is the correct term for it. As human beings, we evolved and gained knowledge on this condition throughout the years, unexpectedly individuals came to realize that A.D.H.D was not just a behavior’s problem that children would normally present while growing up and would go away as they became mature. Doctors came to realize it was actually a chronic nervous condition that affects the anatomy of the brain.

This neurodevelopment disorder is characterized by many symptoms. The main indications are difficulty paying attention or staying focus on tasks or responsibilities, for example it might be easy for a child to start a task, but it might take him longer than a kid without A.D.H.D to finish it due to the problem staying focus on a specific thing at a time. Other symptoms include having imprudent behavior or acting without thinking and being overactive or hyperactive. Even though A.D.H.D. is a common mental disorder affecting many children, sadly, it is not a childhood condition that goes away as you age. Many humans affected by this brain disorder will continue to report symptoms all the way through adulthood. Many adults will not realize they have A.D.H.D. and living with this condition without treatment can compromise basic everyday activities such as staying focus while driving, finishing tasks at work, relationships problems, or even paying attention to a conversation that is going on.

According to Understood.org, there are three subtypes of A.D.H.D., predominantly hyperactive-impulsive presentation, predominantly inattentive presentation and the combined presentation. Kids with the first subtype, predominantly hyper-impulsive presentation, will show difficulty to sit still and will often feel the need to move constantly. Usually they will not show distress paying attention, however, another sign for this type of A.D.H.D is the struggle with impulse control. This type is mostly predominant in very young children and its signs make it easy to recognize. The second subtype, predominantly inattentive presentation, has indications such as difficulty staying focus. Individuals with this type become effortlessly distracted but do not have much distress with impulsivity or hyperactivity. This subtype usually goes unnoticed because the symptoms may seem as if the person was just shy. Although behavior issues are not significant, the struggle with staying focus may still cause them a lot of difficulty trough life. Lastly, the combined subtype will show symptoms previously mentioned in both subtypes above.

But what exactly causes A.D.H.D? While scientists are still trying to find the exact cause for this condition, some of the factors that might aid its development are believed to be genetic. This means that some studies have indicated that A.D.H.D can be genetically pass down between families. For example, three out of four children with ADHD have a relative with the disorder. Another very important factor that may increase the risks of evolving this psychological disorder is the prenatal exposure to toxins such as lead or the use of substances like drugs, alcohol or cigarettes during pregnancy. Let’s understand what goes inside the brain of an individual with this condition. Brain scientist have found that a specific neurotransmitter, which are chemical messengers, they send information between neurons is deficient in the brain of an A.D.H.D individual. This specific neurotransmitter is called norepinephrine. Another important neurotransmitter is Dopamine, which is a compound present in the body and is indispensable for the normal functioning of the nervous system. Dopamine allows us to adjust emotional responses and act in order to accomplish specific rewards. It is also accountable for emotional state of pleasure and reward, therefore it is often called “the reward chemical” or “pleasure molecule”.

In a normal brain, Dopamine is converted into norepinephrine by the enzyme dopamine β-hydroxylase (DBH). In an A.D.H.D brain where these two important neurotransmitters; dopamine and norepinephrine; levels are low, the brain will struggle with neurotransmitter activity in four functional regions of the brain. First, the frontal cortex, which controls high level functions: Attention, executive function and organization. Second, the limbic system, which is located deeper in the brain and oversees the regulation of our emotions and attention. Third, the basal ganglia, which is associated with control of voluntary motor activities, learning, eye movement and cognition. A deficiency here can cause the inter-brain communication and information to “short circuit”, states the ADDtitude magazine in a publication on Sep 26,2017. Lastly, the reticular activating system. This is the most important relay structure among the numerous pathways that enter and exit the brain and a absence here can cause distraction, impulsivity or hyperactivity.

Some researchers believe that dopamine levels may be low because neurons in the A.D.H.D brain and nervous system have higher concentrations of proteins called dopamine transporters. These protein transporters temporarily stop dopamine from going on to the next cell. This decreases the effects of dopamine in the nervous system. The concentration of these proteins is known as dopamine transporter density (DTD). In conclusion, higher levels of DTD might also be a risk factor for A.D.H.D. Now that we know what happens in the brain of a person with this disorder, can we cure it? Unfortunately, as of today there is no cure for A.D.H.D, but there are available treatments that may be of assistance reducing the symptoms and improving functionality of the brain.

A.D.H.D is commonly treated with medication, education or training, therapy, or a combination of all these treatments. One of the most common treatments for ADHD is the use of stimulant medications, such as amphetamines or methylphenidate, which reduces hyperactivity and impulsivity and improves the ability to focus, work, and learn better by stimulating the brain.

Methylphenidate is the most examined of these stimulant medications and it was first approved by the U.S. Food and Drug Administration in 1955 for treating what was then referred to as hyperactivity. For this specific assignment we will investigate how the drug Methylphenidate works explicitly in adults. As we already know, this prescription drug is a stimulant medication that works by increasing the dopamine levels in the brain. Dr. Flavio Guzman, from the Psychopharmacology institute explains that Methylphenidate prevents the reuptake of the two neurotransmitters we were speaking about beforehand, dopamine and norepinephrine. So how does Methylphenidate increase the levels of this neurotransmitters? Well, Methylphenidate regulates the activity of the dopamine transporter (DAT) and the norepinephrine transporter (NET). By doing this, the medication aids to the growth of dopamine and norepinephrine levels in the brain.

There are many reasons why Methylphenidate has become the go-to medication to be prescribed as a way of treatment for patients with ADHD due to its proven benefits in many studies. As we mention before, children are not the only ones affected by this condition. The number of adults using stimulants to control their symptoms is growing rapidly; mentioned Express Scripts in a report they made in 2014. This numbers showed a 53% increase in adults using stimulants in 2012 than in 2008. This means that for every thousand adults, the number of adults using stimulants amplified to 1500 in four years.

The following studies will show numbers that proof of how Methylphenidate improves and/or betters the outcomes on adults than the actual medication compared to adults on placebo. In this first meta-analysis, written by Michelle A. Pievsky and Robert E. McGrath, the authors reviewed 21 double-blind randomized controlled trials with a mean study length of 18 days associating the neurocognitive functioning of adults with attention-deficit-hyperactivity-disorder while on Methylphenidate versus adults on placebo. Included studies had participants 18 years or older and they were diagnosed with ADHD. Three different studies that examined driving performance were included, showing the changes in every day functions such as response time and vigilance. Across 21 studies, adults demonstrated overall improvement in performance as compared to placebo. Effects that were observed in the driving tests were the following domains: working memory, reaction time variability, vigilance, driving and response inhibition. The results of this study demonstrated that Methylphenidate in fact did improve the performance of adults with ADHD on objective neurocognitive measures. These results suggest that Methylphenidate is an effective treatment for ADHD in adults because it improves processes related to concentration and attentiveness and other domains in which individuals with ADHD seem to distinguish from healthy people.

Next, a journal of medicine from Heidi M. Feldman, M.D., Ph.D., and Michael I. Reiff, M.D., present us with a case vignette of a common clinical problem, a patient with ADHD. This journal supports how the use of stimulants (derived from methylphenidate) has shown a clinically noteworthy benefit in reducing the symptoms of ADHD such as inattention, hyperactivity and impulsivity, in short-term randomized, placebo-controlled trials. Although, it is also stated here that comparative-effectiveness studies have shown that stimulants have some adverse effects as with many other medications. However, the positive effects outnumber the negative side effects, the medication comes in different ways of release, sustained release and long- acting doses of the medication is preferred over short-acting agents because they allow the administration of a single morning dose for the entire day instead of multiple doses throughout the day, diminishing the probabilities for adverse side effects. The two most common side effects of stimulants are appetite suppression and difficulty falling asleep.

The following study we are going to discuss about, is a research note conducted by Leah Fostick. This research notes reviews The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, who state that A.D.H.D will continue often into adulthood. An experiment is mentioned, with a total of thirty-three adults diagnosed with attention-deficit-hyperactivity-disorder were included in this study according to the Diagnostic and Statistical Manual of Mental Disorders. The study also included forty-eight adults without A.D.H.D. The experiments goal was to find out if performance regarding judgment tasks was increased while on a certain stimulant (MTH). The set of adults that presented the neurological condition, performed a specific task with and without taking Methylphenidate.

The conclusion of this study showed that while auditory processing difficulties of those diagnosed with ADHD will continue into adulthood, the drug Methylphenidate significantly increased their performance. The numbers measured in this experiment show that Methylphenidate significantly decreased temporal order judgment thresholds within the ADHD group, making their performance comparable to the non-ADHD participants, shown in the next bar graph.

According to a study conducted by Unal, Kenar, Herken, & Kiroglu the following information was encounter. The study was directed on sixty A.D.H.D adults, between the ages of 18 and 60 years old. The patients were distributed according to their A.D.H.D subtypes: 21 of them (35.0%) were in the inattentive type, 11 of them (18.3%) were in the hyperactive type and 28 of them were (46.7%) in the combined type. Levels of choline, a vital nutrient required for many roles of the body, especially for the brain, were measured with magnetic resonance spectroscopy. One of the primary functions of choline is helping brain cells in the production of acetylcholine, a key neurotransmitter for mental focus and learning. After these measurements were obtained, 10mg of oral Methylphenidate was administered to the subjects. Then the levels of choline in the subjects were measured after a break of thirty minutes. The increase of choline levels after MPH compared to the levels of choline before MPH was statistically significant. This experiment shows that Methylphenidate aids in the functioning of the brain of adults with A.D.H.D. by increasing the levels of imperative neurotransmitters.

After reviewing these studies, we conclude that Methylphenidate (MPH) does in fact decrease the symptoms of a person with an attention-deficit-hyperactivity-disorder condition by increasing the levels of neurotransmitters such as norepinephrine and dopamine. These two vital neurotransmitters are deficient in the brain of an A.D.H.D individual and can be increased by taking stimulant medication such as Methylphenidate, as always it is recommended to speak with a health professional regarding the diagnosis and treatment of this condition.

References

1. Feldman, H. and Reiff, M. (2014). Attention Deficit–Hyperactivity Disorder in Children and Adolescents. New England Journal of Medicine, 370(9), pp.838-846.
2. Fostick, Leah. (2017). The Effect of Attention-Deficit/Hyperactivity Disorder and Methylphenidate Treatment on the Adult Auditory Temporal Order Judgment Threshold. Journal of Speech, Language, and Hearing Research, 60(7), 2124-2128.
3. Pievsky, M. and McGrath, R. (2018). Neurocognitive effects of methylphenidate in adults with attention-deficit/hyperactivity disorder: A meta-analysis. www.elsevier.com.
4. Unal, Kenar, Herken, & Kiroglu. (2015). Association of adult attention deficit hyperactivity disorder subtypes and response to methylphenidate HCL treatment: A magnetic resonance spectroscopy study. Neuroscience Letters, 604, 188-192.