Download The Role of Genetics in Addiction

The Role of Genetics in Addiction
MacKenzie Kendrick
1)Neurons are the cells that pass electrical and chemical signals to the brain. They come in all shapes
and sizes. This variation of connection and sizes help them to carry out specialized functions such as
controlling muscles and retaining memory. Information from the neurons flows across a tiny gap called
the synapse where electrical signals are translated into chemical signals to cross the gap. Once it reaches
the other side, it becomes an electrical signal again. One sending neuron can connect with many
receiving neurons, while several receiving neurons can connect with many sending neurons. Cells can
send signals from one region of the brain to the other. The reward pathway reinforces feelings of
behavior, motivation, and reward. The reward pathway is responsible for our good feelings when we
engage in things mandatory for survival, such as eating and drinking. The reward pathway connects to
many other beneficial parts of the brain. These connections allow the brain to find out what is going on
outside the body and strengthen these circuits. For an example, if you are hungry, your five senses
gather that information and another part of your brain tells you that if you eat something, you will feel
better. Once you eat something and satisfy that need for food, a chemical called dopamine is released in
the body and gives you a feeling of pleasure. Your body rewards you for eating the food by making you
feel good. Once you fulfill that need, the reward pathway has the responsibility that you repeat this
behavior. Connections are sent to the part of the brain that controls memory and behavior. Memory
that what you consumed made you feel good is stored, and you will most likely eat the same thing
again. Taking drugs is a different story. There is a similarity in drugs and neurotransmitters naturally
produced in the brain. Some drugs are able to trick the brain's receptors and send unusual messages
through the network. The reward system can become overstimulated by producing large quantities of
dopamine in the circuit. Dopamine is found in regions of the brain that regulate emotions, motivation,
movement, and feelings of pleasure. Nearly all drug abuse activates this system whether it is directly or
indirectly. Stimulants such as a methamphetamine and cocaine and alcohol can activate nerve cells to
produce an excess amount of natural neurotransmitters and complicate regular recycling, which can cut
off a signal between neurons. If you become addicted to drugs and keep taking them, your brain
decreases the number of dopamine receptors available. This destroys the function of the reward
pathway. Long term changes can occur in the chemicals in the brain. For instance, glutamate can cause
changes in cognitive function. Memory, learning, and judgment systems can also be altered by drug use.
2) Many genes linked to addiction are discovered through animals, especially mice. Because the reward
pathway, and many genes that underlie it functions much the same between mice and people. The A1
allele of the dopamine receptor gene DRD2 is more common is more common in people addicted to
cocaine or alcohol. Mice with an increase in expression of Mpdz gene experience less severe with drawl
symptoms from sedative-hypotonic drugs. Mice without the serotonin receptor gene Htr1b are more
attracted to cocaine and alcohol. Mice bred to lack the B2 subunits nicotinic cholinergic receptors have a
reduced reward response to cocaine.Mice with low levels of neuropeptide Y drink more alcohol,
whereas those with higher levels tend to abstain. Mice defected with a Per2 gene drink three times the
amount of alcohol than normal. Alcoholism is rare in people with two copies of the ALDH*2 gene. The
amino acid oxidase activator and circadian genes are linked to methamphetamine use.
3) Alcohol-Ethyl alcohol, or ethanol is found in wine, beer, and liquor. It's an intoxicating ingredient.
Alcohol is produced by the fermentation of yeasts, starches, and sugars. It is rapidly ingested into the
stomach and small intestine and then spreading throughout the blood stream. A standard drink is a 12
ounce beer or 0.6 ounces of pure ethanol, 8 ounces of malt liquor, 6 ounces of wine, or 1.5 ounces of
80-proof distilled spirits or liquor (rum, vodka, whiskey, etc.). Alcohol affects every organ in the body. It
even has the power to hurt a developing fetus. Intoxication can affect motor skills and impair brain
function. Heavy use of alcohol can increase your chances of liver damage, stroke, and certain types of
cancers.
Cocaine-Powerful addictive stimulant made from the leaves of the coca plant, which is native to South
America. Short term effects include euphoria and talkativeness. Long term effects can be potentially
dangerous and include an increase in heart rate and blood pressure. Cocaine is a white, powder like
substance. It can be snorted through the nose and dissolved in the nasal tissue, or dissolved in water
and injected into the bloodstream.
Methamphetamine-An extremely addictive stimulant. It comes in the form of a white, colorless, bitter
tasting, crystalline powder. Meth can be used orally, snorted, smoked, dissolved in alcohol, or injected
into the bloodstream. Meth increases the amount of dopamine in the body, which controls feelings of
motivation, pleasure, and motor function. By taking even miniscule amounts of methamphetamine, the
body can experience increased wakefulness, increased physical activity, decreased appetite, increased
respiration, rapid heart rate, irregular heart beat, increased blood pressure, and increased body
temperature. Long term use of meth can cause massive weight loss, severe dental problems, and skin
sores caused by scratching.
4) One thing many people wonder is whether or not a drug addict can ever leave behind his or her
addiction. Research found that even if a person were to remain in long term abstinence from drugs, the
brain circuitry can never really normalize itself. Brain alterations are still common. To address the issue,
Krishna Patel and her colleagues from Institute of Living/Hartford Hospital conducted a study to
compare neural responses using three groups of people to complete a task similar to bdding for items
on Ebay. The three groups were divided into 47 people who were healthy control, 42 individuals who
were currently drug abusing cocaine, and 35 former cocaine users who had abstained from the drug for
four years. The active users showed abnormal activation in various brain regions involving reward
processing. Past users that had abstained for four years showed had differences in a subset of those
reward processing regions. Both former and current cocaine users had similarly elevated impulsivity
measures compared to the healthy controls. This may indicate that these people may have had a preexisting risk for addiction. The degree of impulsivity correlated with several of the brain activation
abnormalities. This research shows that former drug addicts may only have part of their brain
abnormalities associated with drug use restored to normal.
5) There is an inherited component to addiction. Parents can pass down a drug addiction the their
children. More than 29 percent of teens going through treatment are addicted to some form of
prescription medication such as, opiates, sedatives, and tranquillizers. Over half American adults have a
close family member that experienced alcoholism. In the United States, approximately 1 in 4 children is
exposed to alcohol abuse or dependence in the family. Parents' that abuse drugs hold a chaotic house
hold with child abuse and neglect, which can lead to drug dependence in the next generation. Children
with a drug addicted parent or parents are significantly more likely to have emotional or mental
illnesses, such as anxiety and depression. Children also have a higher risk or physical health problems
and learning disabilities. Children with drug addicted parents are 3 times more likely to be physically,
sexually, or verbally abused and 4 times more likely to be neglected. Adults who are addicted are more
likely to have trouble thinking clearly, remembering, and paying attention. Adults often develop poor
social skills and their work performance and personal relationships suffer. Adolescents who abuse drugs
often have poor grade, drop out of school, and risk unplanned pregnancies, violence, and infectious
diseases.
Identical twins share 100 percent of genes. Any differences in the genes of identical twins is due to
environmental factors. Identical twins are divided into two different categories. The first group grew up
together. They have the same environmental factors until they leave home such as, nutrition, education,
and health care. This means that while the twins are young, developing their own unique qualities is due
to their own personal experiences. The second group of twins would have been raised separately. The
environmental factors are different for the two of them. Non identical twins share 50 percent of their
genes. These two can also be split into groups by those raised together and those raised separately.
Studies have found that if an identical twin is addicted to alcohol, the other twin will also be addicted to
alcohol. If a fraternal twin is addicted to alcohol, the other twin has a chance of becoming addicted, but
it is a smaller chance than if the two were identical.
6)In addiction to nicotine, genetics and environmental factors play a role. The first generation's father
had a nicotine addiction, while the mother was unaffected. A nicotine addiction was then passed on to
certain family members in the second and third generations. Family members that had a nicotine
addiction died earlier and suffered health issues, such as emphysema. Unaffected members lead
healthy, active lifestyles and tended to live longer. Environmental factors such as, mental illnesses and
risky behaviors went hand in hand with nicotine addiction. Victor and Lily from the second generation
were the only couple completely unaffected by nicotine and so were their children. All the other parents
were affected by nicotine in some way, which passed nicotine addiction to some of their children.
7)Teens who start using methamphetamine at such a tender, young age are more likely to drop out of
school, make changes in spending habits, no longer enjoy activities and hobbies, and develop changes in
attitude. Cocaine use in teenagers can offset sleeping habits, cause extreme weight loss due to changes
in eating habits, poor school performance, withdraw or depression, or change in friends. Under aged
drinkers are more likely to be involved in violence, attempt suicide, and develop alcohol problems later
on in life. All three of these drugs can cause many unneeded problems and stresses. The best thing to do
is to abstain from these drugs, as they cause many emotional and physical problems that can ruin a
young life.
8)Doctors have been using Ritalin since the 1950s to treat many conditions such as depression, fatigue
syndrome, and narcolepsy. In 1961, the FDA approved Ritalin for treatment of hyperactivity in children.
Ritalin is prescribed to help many people with ADHD (attention deficit hyperactivity disorder). Although,
this medication is considered to be a stimulant similar to cocaine. Over time, it can cause undesirable
changes in the brain. Even though it is a prescription drug, it has the potential for abuse. People with
ADHD have difficulty concentrating and tend to be hyperactive and impulsive. Having the right amount
of dopamine in the brain is important for behavior. Taking Ritalin increases the amount of dopamine,
helping those with ADHD stay focused. Similarly to cocaine, Ritalin increases productivity and alertness.
Both cocaine and Ritalin increase dopamine levels and they have similar chemical structures. Both drugs
increase dopamine levels by blocking the dopamine transporter, causing dopamine to build up in the
synapse. Usually, children are taken off of Ritalin once they reach adulthood. Once they get taken off of
it, they are prone to becoming addicts. This is a form of self medicating. Whether they realize it or not,
they are actually substituting Ritalin for cocaine because the drugs act the same way. Using cocaine may
help individuals with ADHD feel calm and focus.
9)Depending on the type of drug, the brain of the mouse was altered in some way. The mouse on
methamphetamine caused an excess amount of dopamine to be released, which caused the dopamine
transporters to work in reverse by pumping dopamine out of the cell in into the synapse. The receptors
bind with the dopamine repeatedly, which overstimulates the cell. Meth users feel intense pleasure and
exhilaration due to the affects on the reward pathway. With alcohol, the mouse's GABA receptors and
glutamate receptors were inhibited. It interacts with GABA receptors to make them even more
inhibitory. It then binds with glutamate receptors to avoid binding with the cell. Memory, decision
making, and impulse control were affected. Cocaine blocks dopamine transporters, trapping dopamine
in the synaptic cleft. Dopamine minds with the receptors over and over again, which overstimulates the
cell. Cocaine affects the reward pathway and parts of the brain that control voluntary movements. This
causes users to be fidgety and not sit still.