Effects of Drugs on the Brain

Drug Effects 10

Effects of Drugs on the Brain

by

Miriam Avalos

Axia College of University of Phoenix

Drugs have numerous internal and external effects on the body. Prescriptions, illegal drugs, nicotine, caffeine and alcohol affect the body and brain in different ways. With consistent use and abuse of drugs, a person’s different internal organs slowly deteriorate, especially the brain, as the skin and face do on the outside. In addition to the physical changes, psychological effects of these drugs come from the chemical imbalance and false messages sent to the brain. Most drugs interfere with neurotransmitters, which are the chemicals used to send information between the brain and other parts of the body. Most information is related to the neurotransmitter dopamine, but this may simply be a case of that being the subject of the most research.

Addiction is a complex disease. Physiological, genetic, psychosocial, nutritional and environmental factors are often thought to lead to the development of this disorder. These all need to be addressed during recovery along with the physical damage. These factors can cause a person to act in a pattern of unhealthy, compulsive behavior which the person carries out uncontrollably, resulting in the chronic use of a certain substance or stimulus such as alcohol, drugs, sex, gambling or cigarettes (MyAddiction.com, 2006).

Addiction almost always has a level of psychological dependence, as well as the physical dependence. Persistent need to use, failure to want to stop, using regardless of dangers, using to cope with life, being preoccupied with obtaining the drug of choice – these are all evidence of addiction.

The brain relies on neurotransmitters to function. The neurotransmitters bind to certain receptors which in turn initiates a biological response. For example, emotion or muscle movement may be the response. Each drug affects the body differently but uses the same basic process.

When drugs enter the brain, they bind to the neuron’s neurotransmitter receptors instead, and the receptor initiates a response, that response is the 'high'. As prolonged abuse becomes addiction, that drug goes from being the brain's disruptive houseguest to its newest homeowner. It hijacks the receptor for so long that the brain stops making the neurotransmitters for that receptor (MyAddiction.com, 2006). The lack of the neurotransmitter causes physical and psychological changes in the person.

There is another process which sometimes occurs when a drug highjacks a receptor; that is that the neurotransmitter becomes trapped between neurons, and the brain must cope with an overproduction.

The addiction has introduced a change to the brain which is physiological. Now the brain is diseased and will continue to be long after the addict stops using the drug. Some of the changes to the diseased brain are not reversible. Addiction is a treatable disease but not always curable. Even if the physical condition is corrected, the psychological factors which triggered the original addiction need to be addressed and corrected to avoid a relapse.

Withdrawal occurs when an addict has used a drug long enough to create a physical dependence within the brain and body. When the drug is suddenly discontinued, the user goes into physical withdrawal; symptoms differ depending on the drug, but the general experience is driven by the brain and involves intense cravings that are manifested in physically painful and devastating ways. Withdrawal is the first step in an addict beginning to beat addiction. The psychological withdrawal needs to be addressed as well. In this process the addict is fighting his or her own thoughts as well as the physical need for the drug. Below you will see a chart showing the ratio of fatal dose to effective dose.

Chart showing lethal level of drugs

(Center for Disease Control and Prevention, 2007)

Addictive drugs enter the body through a number of routes, make their way into the bloodstream, and go straight to the brain where they exert their effects (National Families in Action, 2008).

Alcohol addiction can be hereditary; the addictive response to alcohol seems to be passed down. “Small amounts of alcohol produce pleasant feelings to the user. Depressant effects on the brain come into play when large amounts are used. Judgment, reaction time, speech and motor control are increasingly impaired with increasing amounts of alcohol” (National Families in Action, 2008). “Excessive amounts of alcohol can cause an overdose and death. This is caused by reducing the number of messages the brain sends to the chest muscles to breath. The victim of alcohol stops breathing due to the lack of message from the brain and dies. Long term effects are dependency and addiction. Over a long period of time alcohol use can cause permanent brain damage by destroying the short-term memory part of the brain.” (NIDA, 2009)

Cocaine is a very highly addictive drug. Crack cocaine is usually smoked, so high doses reach the brain very quickly through the lungs and mouth. Both crack cocaine and the powder form of cocaine trap dopamine between the brain’s nerve cells. Dopamine constantly stimulates nerve cells, giving the user an intense feeling of pleasure. The brain begins to respond to the mass amount of this chemical by destroying some of the chemical and shutting down the receptors so that dopamine’s message is not received. This process causes the user to use cocaine more often and larger amounts to get the same feeling as he or she received when the drug was first used. High doses of this drug cause paranoia, aggressive behavior, and violent behavior. This drug creates exaggerated feelings of confidence and interferes with the individual’s judgment.(MedicineNet.com, 2009) This gives the user a “speeded up” sensation, making his or her feel more powerful and quick of wit, and giving a sensation of energy. For this reason, people who “live by their wits” or who are overworked tend to favor the use of the drug.

Heroin is a highly addictive drug which is injected into the veins of the user. This drug is said to have users addicted after the first use. The brain has what is called an opiate receptor. Two natural substances in the brain, endorphins and enkephalins, normally bind to this receptor and relieve pain. Opiate drugs such as heroin fit into this receptor, change the way the brain works, and produce addiction (National Families in Action, 2008). Heroin may depress the body's ability to withstand infection. It produces euphoria, drowsiness, respiratory depression, constricted pupils and nausea. As heroin leaves the body the users has severe flu-like symptoms. (NIDA, 2009)

Inhalants are products bought at stores such as glue, gasoline, and aerosols that are abused by users by sniffing or inhaling them to get a high. Inhalants act on the brain and destroy the outer lining of nerve cells, making it impossible for those cells to communicate properly. Symptoms of use include dilated pupils, blisters or rash around the nose or mouth, chronic cough, nausea and headaches, disorientation, and a chemical odor on breath. After only six months of use, the brain, lungs, nerves, liver, kidneys and bones may be permanently damaged. (NISA, 2009) The sheath around neurons cannot be rebuilt even after withdrawal.

Marijuana is usually smoked as a cigarette or in a pipe. Scientists have learned a lot about how marijuana’s THC chemical acts on the brain..

“When someone smokes marijuana, THC rapidly passes from the lungs into the bloodstream, which carries the chemical to the brain and other organs throughout the body.THC acts upon specific sites in the brain, called cannabinoid receptors, kicking off a series of cellular reactions that ultimately lead to the “high” that users experience when they smoke marijuana. Some brain areas have many cannabinoid receptors; others have few or none. The highest density of cannabinoid receptors are found in parts of the brain that influence pleasure, memory, thoughts, concentration, sensory and time perception, and coordinated movement. Not surprisingly, marijuana intoxication can cause distorted perceptions, impaired coordination, difficulty in thinking and problem solving, and problems with learning and memory. Research has shown that marijuana’s adverse impact on learning and memory can last for days or weeks after the acute effects of the drug wear off. As a result, someone who smokes marijuana every day may be functioning at a suboptimal intellectual level all of the time. Research on the long-term effects of marijuana abuse indicates some changes in the brain similar to those seen after long-term abuse of other major drugs.” (MedicineNet.com, 2009). Users’ minds tend to wander so concentration is difficult .

Chart showing annual deaths by drug reaction or interaction.

Ecstasy is a mind altering drug with amphetamine-like and hallucinogenic properties. Amphetamin is another “speed-up” drug; a hallucinogen causes hallucinations. Research links ecstasy use to long-term damage to those parts of the brain critical to reason and memory. It is thought that the drug causes damage to the neurons that use serotonin to communicate. “In monkeys, exposure to ecstasy for 4 days caused brain damage that was evident 6 to 7 years later.” (NIDA, 2009) Ecstasy has also been shown to cause degeneration of neurons containing dopamine. Damage to these neurons is the underlying cause of the motor disturbances seen in Parkinson's disease. (NIDA, 2009)

“Smoking tobacco is highly addictive due to the nicotine that enters the body when inhaling the smoke. Smoking cigarettes produces a rapid distribution of nicotine throughout the body, and reaching the brain within ten seconds of inhalation. The nicotine causes a release of dopamine, neurotransmitters that carry information across synaptic clefts, in the dopamine circuit. This circuit, known as the brain's pleasure center, is an anatomically small cluster of cells. It has evolved over millions of years and mainly seems to reward activities that increase the likelihood of survival, such as sex and eating. This cluster of cells might be small but it reaches into regions of the brain involved with a variety of tasks. These dopamine-releasing pathways course from the evolutionary older part of the midbrain to the hypothalamus and trigger activity of other cells that extend from one part of the midbrain to an area in the forebrain known as the nucleus accumbens. It also branches out to the emotion-associated region and into the cortex, the seat of conscious learning. Chronic exposure to nicotine results not only in physical addiction but also in mental addiction. Cigarette fixation is a combination of nicotine dependency due to the nucleus accumbens wanting more dopamine as it is stimulated, and deeply engrained behavior habits. For some people, the feel, smell, and sight of a cigarette and the usual rituals of obtaining, handling, lighting, and smoking the cigarette are all associated with the pleasurable effects of smoking. Also, places and times can have traditions of smoking built into them, like after sex, after meals, driving in a car or walking to class or work. These particular rituals, times, and places associated with the pleasurable effects of smoking can cause cravings and make withdrawal worse. Research is just beginning to document all of the neurological changes that accompany behavior that helps to develop and maintain nicotine addiction. Memory and habit have their own neural pathways that reinforce the addiction problem. The broad reach of dopamine into the limbic system might explain why certain emotions, smells or events stir the want for a cigarette.” (NIDA, 2009)

Nicotine is only one of the chemicals found in the smoke from tobacco products. Carbon monoxide binds to hemoglobin and thereby reduces the usual binder for oxygen, which is necessary for cellular metabolism. “Research is also beginning to show that there are other psychoactive ingredients in tobacco. Using neuroimaging technology, scientists can see the dramatic effect of cigarette smoking on the brain, and are finding a marked increase in the levels of monoamineoxidase (MAO), an important enzyme that is responsible for breaking down dopamine. This decrease in two forms of MAO results in higher dopamine levels (that results in increased desired dopamine sustainment) and may be another reason that smokers continue to smoke.” (NIDA, 2009) Since the psychological needs which cause people to start and continue using tobacco products are so wide spread, and the physical damage so complex, more research needs to be done on how to achieve a permanent withdrawal.

Prescription drugs are under the control of the FDA because of their side effects and/or their addictiveness. The ones that are abused fall under three main types, opioids (to treat pain), central nervous system depressants (to treat anxiety and sleep disorders), and stimulants (to treat narcolepsy, ADHD, and obesity).

“Vicodin, like other narcotics, relieves pain. It does so by binding to receptors in the brain and spinal cord. … It is for this reason, that individuals who can afford to seek medical treatment are more likely to become addicted to this drug.” (NIDA, 2009) Most prescription drug abusers start out as regular medical patients.

People can become addicted to drugs of one sort or another by various means – prescribed medication, family practices, psychological needs or social environment. But the sense of release while on these drugs is a false sensation given by the brain to the body. Some of these drugs may be used for many years without the user having any complications or sense of the dependency he or she is under. On the other hand, it may be the first time using a drug that causes a person to be physically or mentally impaired, or even cause death. No matter when the user actually recognizes the problem, the damage physically begins at the very onset of use. And the user needs to be aware that some of this damage can never be undone.

References

Bureau of Justice Statistics, (2009).Drug use. U.S. department of justice. Retrieved on July 31, 2009, from http://www.ojp.usdoj.gov/bjs/dcf/du.htm

Medicine Net. (2009). Drug abuse and addiction. Retrieved on July 31, 2009, from http://www.medicinenet.com/drug_abuse/article.htm

MyAddiction.com. How addiction affects the brain (2008). Retrieved August 27, 2009, from http://www.myaddiction.com/education/articles/addiction_brain.html

National Families in Action. A guide to drugs and the brain (2008, August 26). Retrieved September 2, 2009, from http://www.nationalfamilies.org/brain/index.html