What Is The Drug Ritalin Chemical Makeup

Ritalin and the Human Encephalon

Last Updated on Wed, 16 Mar 2022 | Ritalin

Attention-Arrears/HYPERACTIVITY DISORDER: SYMPTOMS IN SEARCH OF A Cause

The symptoms of inattention, distractibility and/or hyperactivity that define attention-deficit/hyperactivity disorder (ADHD) better when treated with the stimulant drug Ritalin. For long-term success, however, the behaviors associated with these symptoms can too addressed with dissimilar techniques, some of which take been described in Chapter 2.

These two unlike types of treatments point to 2 different causes for ADHD. The comeback observed when taking a chemical substance seems to signal that ADHD has a biological cause. Yet, comeback by behavioral modification techniques suggests that ADHD may accept an ecology cause.

ADHD: A BIOLOGICAL Cause?

The prevalent theory amidst both health professionals and the full general public today is that the symptoms of ADHD have a biological cause. The nigh more often than not cited causes are nascency defects, an babe trauma, and the brain's inability to produce enough of specific neurotransmitters, or brain chemical messengers.

The widespread utilise of expressions such every bit "He has a chemical imbalance" or "Her brain is difficult-wired this way" when talking about children considered to have ADHD reinforces this belief. Although the lingo may exist new, the theory of a biological cause for ADHD-like behavior is more than 100 years old. In 1902, the British physician George Still attributed the aggressive and defiant behavior of the children he was studying to either a genetic cause or some nascency-related injury. Brain damage was besides thought to be the cause of the behavioral problems experienced by the children who had survived the encephalitis outbreak of 1917-1918. As belatedly as the 1950s, symptoms like to the ones now included in ADHD were grouped under the term minimal brain impairment. This physiological encephalon damage was never institute, and eventually the term was abandoned. The search for a biological cause for ADHD, however, was not.

Although there is testify that ADHD is hereditary, it has proven difficult to separate the furnishings of genetic inheritance from those of family environment. The but data pointing to a genetic component for ADHD have been compiled when working with identical twins. These studies constitute that it was more than likely for identical twins to encounter ADHD criteria than information technology was for fraternal twins. Since, by definition, identical twins accept the same genetic textile, this indicated that at least part of the ADHD condition is genetic. Yet the probability for one identical twin to accept ADHD if the other had it was less than one in iii. Moreover, to appointment, no specific factor for ADHD behavior has been identified.

Using different techniques of brain imaging, several groups of researchers accept looked for differences between the brains of ADHD and non-ADHD individuals. In one of the best-known studies, Alan Zametkin and his colleagues at the National Constitute of Mental Wellness used positron emission tomography (PET) scanning to evaluate glucose metabolism in the encephalon. Because glucose is the only source of energy for the encephalon, the way the brain uses glucose tin serve every bit a gross indicator of action in its diverse parts.

For the studies, patients were given radioactive glucose. Because of the high level of radiations associated with this technique, the studies were non done on children merely on adults idea to have suffered from ADHD as children. The results, published in the New England Journal of Medicine in 1990, showed a 8.1% decrease in brain metabolism, pregnant that glucose was underutilized, in the group who had ADHD as children compared with those who did non.11 This difference in the rate of metabolism led scientists to the conclusion that they had located a biological cause for ADHD.

Magazines and newspapers embraced this conclusion eagerly. Later all, how tin you argue with a brain scan? Fourth dimension magazine, in an article called "Why Junior Won't Sit Even so," noted that in a "landmark study that could assist put to rest decades of confusion and controversy, researchers at the NIMW have traced Add together ... to a specific metabolic abnormality in the brain."12 The New York Times, Washington Post, and Newsweek joined in the reporting of this apparent breakthrough.

Despite the fizz, not everyone was convinced that the results proved that ADHD has a biological basis. First, efforts to replicate these findings have failed. Second, the participants were adults, non children, which limits the applicability. Third, there is no evidence that an 8.one% difference in brain metabolism produces a significant deviation in beliefs, including hyperactivity. In fact, this difference in metabolism did not correlate with performance on an attending chore. Fourth, 72% of participants in the hyperactive group were men, compared with the control group, which was only 56%. When another group of researchers compared the metabolism of men and women in the control group of the Zametkin written report, they found the statistical divergence to be the same as the 1 they had institute betwixt the command and the hyperactive groups. This means that the difference between the hyperactive and command grouping in Zametkin's report could be the result of the hyperactive grouping having a larger percentage of males. Finally, fifty-fifty if the departure in encephalon metabolism between the two groups were real, this does not mean the decreased metabolism is the cause of the hyperactivity.

In 1993, Zametkin and colleagues published a follow-upwardly report in which they performed PET scanning to measure glucose metabolism in the brains of ADHD and non-ADHD adolescents. This time, they found no departure between the brains of the ADHD adolescents and the not-ADHD adolescents.

In a later written report, they looked at the glucose metabolism in the brain of ADHD individuals before and afterwards taking Ritalin. The idea was that if ADHD symptoms are caused past a decrease on glucose metabolism and Ritalin improves ADHD symptoms (their hypothesis), then taking Ritalin would increase glucose metabolism. Once more, their results failed to show any change.

Even Zametkin has admitted that PET scanning cannot tell whether a person is ADHD. "One unremarkably asked question of our brain imaging studies," he has stated, "is whether PET scanning can be used to diagnose ADHD. Unfortunately, this is non currently possible because at that place is considerable overlap in our study betwixt normal and ADHD brain metabolism."xiii

Yet, because Zametkin's follow-up studies did not reach the printing, his start results were never challenged publicly, and PET scans are still mentioned today every bit the ultimate proof for the biological cause of ADHD. As an example, psychoanalyst Frederick Fisher, as recently equally March 16, 2003, stated in the Philadelphia Inquirer mag that ADHD "is a demonstrable organic condition that shows upward on PET (positron emission tomography) scans involving glucose metabolism."14

Two Californian physicians, Daniel Amen and Blake Carmichael, have used another radiological technique— unmarried photon emission computed tomography (SPECT) scanning—on more than than two,000 patients, including adolescents and children. This process, which uses less radiation than PET, detects variation in blood flow (and indirectly detects biochemical activeness) in the brain. These researchers claim there is a correlation betwixt ADHD and decreased blood period in the tissues of the prefrontal cortex (Figure three.1). Although other experts have criticized the lack of reproducibility of this study, Amen believes the scanning is evidence of the biological nature of ADHD and uses it to diagnose ADHD.

In summary, no reliable scientific evidence for the biological cause of ADHD has been constitute to engagement. Zametkin, the researcher behind the PET scan studies on the encephalon, agrees:

Could it exist that a dysfunction of the central nervous system is the key to our understanding of the etiology of attention arrears disorder? Individually, each finding is insufficient to bear witness that ADHD has a neurobiological basis. Indeed, it may still be a long time until the underlying cause of ADHD is established.xv

ADHD AND THE ENVIRONMENT: NATURE VERSUS NURTURE

In the book The Music of Dolphins, Karen Hesse tells the story of a girl raised by dolphins from the age of four. Rescued as a teenager, she is taught how to talk and behave like a human. Although she progresses to a signal where she is able to communicate, she cannot become fully integrated into a society she all the same perceives every bit alien.

This story, which closely follows the modern theories nigh voice communication and behavior development, shows how much influence the environment has in shaping the self. In other words, the story shows the importance of the nurture function in the old argument of nurture (the influence of environment) versus nature (the influence of genetic makeup). Although the daughter in the volume had the genetic makeup to be human, without

Templates For Chinese Umbrellas

Effigy three.1 Although no biological cause has yet been found for ADHD, some scientists accept offered studies using PET and SPECT scans that may demonstrate a link between ADHD-type beliefs and decreased claret flow in the prefrontal cortex of the brain. This diagram of the encephalon shows the cerebral cortex—the area that some researchers posit may exist connected to ADHD.

Figure 3.1 Although no biological cause has yet been found for ADHD, some scientists have offered studies using PET and SPECT scans that may demonstrate a link between ADHD-blazon behavior and decreased blood menstruum in the prefrontal cortex of the brain. This diagram of the brain shows the cognitive cortex—the area that some researchers posit may exist connected to ADHD.

the proper stimuli while growing up, her encephalon did not develop to its total potential.

Every bit Daniel Goleman writes in his book Emotional Intelligence, there is increasing evidence that to develop in a healthy way, a child'due south brain needs real-life experiences. The experiences after nascency, rather than something innate, determine the bodily "wiring" of the human encephalon. "Wiring" refers hither to the connection the neurons (brain cells) make with i another (Effigy three.two). If we consider that the human brain is composed of almost 10 to 100 billion neurons, and that these neurons make thousands of connections with other neurons, we come up with a web of billions of connections. These connections, still, are non present in the newborn baby's encephalon. In the newborn's brain, virtually iv.7 million branches abound out from neuron to neuron every minute. Although the genome has a role in this circuitous process, it is the moment-to-moment feel of the child that determines which connections volition remain and which volition be cut.

Many examples suggest this plasticity. For example, if a child with a lazy eye covers the healthy centre, eventually the vision in the weaker eye improves because the neurons grow new connections to reinforce the path to the weaker eye. A child born in China learns to speak Chinese, while the same child raised in England would larn to speak English. Although every child growing upwards in Spain knows how to roll the "r," it is difficult for an adult nonnative speaker to learn to do then.

If environmental influences can actually alter brain functions and shape behavior, it is not surprising that many people believe a child's early experiences accept an consequence on whether he or she develops ADHD. In other words, some experts contend that the environment tin cause or change ADHD.

Several studies back up this theory. I of them, published in 1995, observed 191 children at six-calendar month intervals during early and middle childhood. The written report found that variables operating at the level of the family unit (mainly, quality of intendance giving, parents' marital status at the fourth dimension of the child's nascence, emotional support given to the caregivers, and the caregiving style) were good indicators of which children would or would not show ADHD-related problems. The results indicated that the child's early experiences do have an result on the development of ADHD.xvi

Ritalin And Cocaine Structure

Figure iii.2 This diagram of a neuron shows the complex construction that allows signals to travel dorsum and along between the brain and the nerves of the body. The human being encephalon is fabricated up of billions of these neurons. Scientists who believe ADHD may have a biological cause are researching possible links between connections between neurons and the behavioral problems that are associated with the condition.

Figure 3.two This diagram of a neuron shows the circuitous structure that allows signals to travel back and forth betwixt the brain and the nerves of the body. The man encephalon is fabricated up of billions of these neurons. Scientists who believe ADHD may accept a biological crusade are researching possible links between connections betwixt neurons and the behavioral problems that are associated with the status.

THE "BIOPSYCHOSOCIAL" MODEL

If the biological cause for the ADHD behavior is accepted, the utilize of medication as a "cure" easily follows. If, on the other paw, emotional or relational problems are considered the crusade, medication is no longer the simple cure, and the techniques offered for improvement (psychological and social approaches) are longer and more time-consuming.

The biological cause model remains popular because a solution in pill form is highly-seasoned and because accepting a biological cause removes blame from parents. Still to believe just in a genetic and neurological cause for the disorder would entail ignoring many environmental factors, such as learning disabilities, emotional bug, family dynamics, classroom size, and economic and cultural problems, which may also exist of significance in the development of ADHD.

Lawrence Diller believes that neither the genetic model nor the surroundings model alone provides the whole picture for ADHD. Instead, he argues that a "biopsychosocial model," in which several factors—including a person'southward biology, emotional status, and environment interact—provides a better solution. In this model, the path between the mind and the body is seen as a 2-style street: The brain affects emotions and behavior and, in turn, the brain is affected by the person's experiences. Later all, although anybody is born with a bones personality, information technology is the experiences an individual has while growing up that will shape him or her into the kind of person he or she will go.

Upshot OF RITALIN ON THE Encephalon

Regardless of what causes ADHD, the behavior of a person with ADHD improves in the brusk term afterward taking a stimulant drug such every bit Ritalin. Ritalin as well improves concentration, increases attention span, and lowers the activity level both in individuals with ADHD and without. On the other hand, Ritalin may crusade several adverse drug reactions, from growth inhibition to psychosis.

How Ritalin accomplishes these changes is non completely understood. Nonetheless, several studies have shown that stimulants touch on the structure, biochemistry, blood flow, and free energy utilization of the brain. The areas of the encephalon affected

Tabular array 3.one Effect of Stimulants in Various Areas of the Brain
Surface area OF BRAIN	Furnishings OF STIMULANTS
Basal Ganglia	Aberrant movements (i.e., trouble walking),
	impaired emotional chapters
Cerebellum	Dumb coordination
Cerebral Cortex	Damage of higher mental activities,
	such as intelligence and sensory perception
Frontal Lobe	Reasoning, judgment, and emotional
	impairment
Hippocampus	Impairment of memory and learning
Hypothalamus	Impairment of temperature and hormone
	regulation, appetite problems
Limbic System	Emotional dysfunction
Parietal Lobe	Impairment of sensory perception
Pituitary Gland	Growth problems, sexual dysfunction
Reticular Activating	Impaired responsiveness, alertness, and
System	cocky-awareness
Spinal Cord	Impaired muscle tone and movement
Temporal Lobe	Impairment of memory and learning

by stimulants are shown in Figure 3.i on page 43. Table 3.1 summarizes the upshot of stimulants in diverse areas of the brain.

On a physiological level, Ritalin causes a 23 to 30% subtract of the overall blood flow in all areas of the human brain, as measured by a PET browse. This reduction is believed to be caused by a constriction of the blood vessels, probably related to Ritalin's touch on the neurotransmitter dopamine. Ritalin likewise has a significant outcome on glucose metabolism in the brain. As noted previously, since glucose is the only source of energy in the encephalon, its metabolism is direct related to the brain'southward overall energy consumption. At the everyman dosage, Ritalin increases free energy consumption in many areas of the brain that are fundamental to motor activity and mental office. Most of these areas are dopamine pathways.

Other studies suggest that in the long term, Ritalin may also crusade cortical atrophy, which refers to the withering and shrinking of brain tissue. This finding poses great concern, since the cortex of the encephalon is critical to higher mental function, including intelligence.

Upshot OF RITALIN ON NEUROTRANSMITTERS

The brain is composed of cells called neurons. Unlike other cells in the body, neurons do not touch each other. The connection between any two neurons is made through neuro-transmitters, chemicals that human activity as messengers.

Neurotransmitters are very small molecules. They are released from the tip of the neuron extension, or axon, into the space (chosen a synapse) that separates individual neurons (Effigy three.3). As a result, electrical impulses travel downward the neuron membranes. Once neurotransmitters are released, they travel through the synapse until they are picked upward by receptors in the neighboring cells. Some neurotransmitters decrease (inhibit) activity, while others increase (excite) activeness of the neuron to which they demark. Any particular neuron may be surrounded by thousands of others that are, at whatsoever given moment, releasing neurotransmitters. The neuron must weigh the relative strengths of the inhibitory and excitatory signals of these neurotransmitters to determine when a signal should exist sent downwardly its axon.

Ritalin interferes with this complex neurotransmitter system both by increasing the number of neurotransmitters released

How Ritalin Works

Figure iii.3 Ritalin works by affecting the communication betwixt neurons and the neurotransmitters serotonin, dopamine, and norepinephrine. Ritalin and other stimulants increase the number of neurotransmitters released into the synapses (the spaces between individual neurons) and assist continue the neurotransmitters in the synapse longer than they would remain without the drugs. This diagram demonstrates the menstruation of neurotransmitters between neurons, beyond a synapse.

Figure 3.3 Ritalin works by affecting the advice betwixt neurons and the neurotransmitters serotonin, dopamine, and norepinephrine. Ritalin and other stimulants increase the number of neurotransmitters released into the synapses (the spaces between private neurons) and assist keep the neurotransmitters in the synapse longer than they would remain without the drugs. This diagram demonstrates the flow of neurotransmitters betwixt neurons, across a synapse.

in the synapses and by reducing the rate of their removal, so that the neurotransmitters stay in the synaptic space longer.

Different neurons synthesize and release dissimilar neuro-transmitters into the synapses. Ritalin and other stimulants interact with the neurons that produce and answer to the neurotransmitters dopamine, norepinephrine, and serotonin.

l RITALIN DOPAMINE

The activation of the dopamine pathways in the brain, researchers believe, produces the therapeutic upshot of suppressing spontaneity as well equally the near serious adverse effects of drug abuse and habit. These effects occur because the neurons that release dopamine originate in 2 areas deep within the encephalon: the substantia nigra and the ventral tegmentum. Dopamine neurons in the substantia nigra reach into the basal ganglia, which command motor activity and influence mental processes. These ganglia are connected to the reticular activating organisation that is the energizing core of the brain and the limbic arrangement that regulates emotions. Dopamine neurons from the ventral tegmentum go directly to the centers of the brain that command thinking and feeling, including the frontal lobes and limbic organization. The dopamine system thus affects portions of the brain involved with the processes well-nigh essential to being human.

Dopamine neurons besides go to the hypothalamus and pituitary glands. There, they control the hormonal processes involved in growth and reproductive functioning.

NOREPINEPHRINE

Ritalin as well stimulates neurons that release norepinephrine into the synapse. This is believed to result in overactivity of the cardiovascular arrangement and some symptoms of drug withdrawal. Most of the norepinephrine-generating neurons originate in the locus coeruleus of the brain. This locus is connected to the cerebral cortex and the reticular activating organisation.

SEROTONIN

Past increasing the activity of the neurotransmitter serotonin, Ritalin affects both higher man activities and basic physiological functions. In fact, increasing serotonin levels affects every brain function described in Table 3.1 on folio 47. Some researchers believe that Ritalin produces more farthermost mental aberrations, including psychosis and delusions, by affecting the serotonin pathways in the encephalon.

The relationship between Ritalin and the overall mental function of the brain is far from being well understood. Dopamine, norepinephrine, and serotonin—the neurotransmitters known to be affected by Ritalin—are only three of the hundreds of substances that control brain functioning.

The brain does non welcome external molecules. It sees them as intruders and tries to compensate for their effect. In the example of stimulant drugs, the brain reacts to the backlog of neurotransmitters in the synapse in ii ways:

1. The neuron releasing the neurotransmitter receives feedback signals that crusade it to shut down, causing less neurotransmitter to be released into the synaptic space.

2. The neuron receiving the neurotransmitter tries to reduce the amount of stimuli past destroying the receptors that bind to that item neurotransmitter. The disappearance of the receptors has actually been measured in experiments with animals.

Sometimes, these compensatory changes in the brain become permanent, causing irreversible malfunction.

In summary, although its advocates merits that Ritalin corrects an imbalance in the brain or enhances brain function, the reality is not and then simple. The only matter sure is that Ritalin, similar any external substance that reaches the brain, has a loftier probability of disrupting the normal mental process in unexpected ways.