Introduction
View of Drugs Overtime
Effects of Drugs
Mechanisms of Addiction
Changes In the Brain
Effectiveness of Treatment 
How Can We Improve?
Photo by Pixabay
Photo by pixabay
Introduction
We will be researching the biological effects of drugs on the brain, specifically how neurotransmitters work in the brain. We will begin by focusing on how drugs have evolved over time and how that has led us to the findings we now use today. Then we will focus on the effects neurotransmitters, like how dopamine and serotonin affect the brain when taking drugs. We will study this by looking at how drugs can help medical illnesses like Alzheimer’s and if rehabilitation is biologically affective.
Parts of the Neuron
Soma- the cell body that contains the nucleus and other organelles
Dendrites– treelike projections that receive information from other cells
Axon- tubular extension that conductions electrical signals from the cell body to the terminal buttons on the axon terminal
Terminal buttons– contain the neurotransmitters
Nucleus- brain of the cell
Synapse – gap between neurons, where information is passed from one neuron to another
Myelin- fatty insulating coating which covers the axons
Nodes of Ranvier- bare spots on the axon which is where the action potential is sent along the length of the action
Axon Hillock- where the action potential is generated, which is an electrical signal sent from one neuron to another
Source: Psychopharmacology By Jerrold S. Meyer and Linda F. Quenzer
Timeline:
1500’s – alcohol and tobacco
1600’s – marijuana
1800’s – opium
- 90’s- morphine
1900’s- tranquilizers and sedatives
- 40’s- amphetamines
- 60’s- LSD and heroin
- 80’s- crack
Today- synthetic drugs and prescription painkillers
Drug use in America
Drug use is not a new concept in American society. For generations, citizens have used many substances for recreational use, pain relief, and illness over the years to bring us to where we are today:
1500’s: Tobacco and alcohol were introduced and were the most popular drugs in use to the Civil War
1600’s: Marijuana cultivation was introduced to Kentucky
1800’s: Chinese immigrants brought the idea of smoking opium to the U.S.
1900’s: With the development in the fields of chemistry and pharmacology during the 20th century, new and more potent drugs were developed. Drugs such as amphetamines or LSD were initially developed for medical purposes soon became part of the popular drug use culture. Tranquilizers and sedatives were brought into society when prescribed to help sleeping problems.
Today: synthetic drugs and prescription painkillers came into play, adding to this already long list of active drugs in the U.S.
Image by Pixabay
Attitude Towards Addiction
The idea of addiction is relatively new. 150 years ago, addiction was not viewed as a disease and there was no proper treatment available. Addicts in America were deemed as criminals in which prosecution was the only option, often landing them in psychiatric centers and asylums since there were no treatment centers. During the mid 19th century, American citizens chose only to believe that drug problems existed among lower socioeconomic groups. Almost 100 years later, society’s position on drug use had not seen change. People chose to neglect the country’s drug problem, especially among the soldiers that had returned from Vietnam. Due to the efforts they made and the trauma they faced (The River Source), society justified their drug use, especially seeing the stress disorders that followed soldiers back from Vietnam.
No one understood drugs in society and to treat them. It was not until the 1960’s when attitude toward addiction started to change for the better. Drug use became a part of society– especially during Vietnam and the Anti-War Movement. The country began to accept addiction as a disease that needed treatment; lawmakers even began recommending treatment over criminal prosecution. Doctors began taking interest in addiction, studying it and ways to properly treat it using medication. Society has come to realize that addiction is a chronic disease of the brain which brings about impulsive behavior.
For more information on the perception of drug use in America over the years, you can visit The River Source.
Physical and Psychological Effect of Steroids (Synthetic testosterone)
Some physical side effects of anabolic steroids are shrinking of the testicles, excessive hair growth in women, deepening of the voice in women, growth of breast tissue in men, menstrual irregularities for women, fertility issues, heart problems, elevated blood pressure, mood swings, mania and stroke. Other short-term effects of anabolic steroids are acne, mood swings, restlessness/agitation, fatigue, decreased appetite, trouble sleeping, decreased sperm count, and impotence. The long term effects of anabolic steroids are anger and aggression (“roid rage”), paranoia, delusions, heart attack, stroke, kidney failure, tumors in the liver, and blood-borne diseases.
Marijuana (Cannabis Sativa with active ingredient THC)
Marijuana can cause side effects such as temporary memory loss, lack of coordination, altered perception of time, mood changes, and difficulties thinking or problem-solving. For long-term effects, marijuana can cause cognitive impairment, respiratory issues, increase depression/anxiety, and can enhance the onset of schizophrenia.
Methamphetamine (White crystalline drug)
The short-term effects of meth are aggression, hyperactivity, heightened awareness, appetite loss, hypertension, inability to sleep and heart abnormalities. Long-term side effects of methamphetamines are prolonged appetite suppression, rapid weight loss, amphetamine psychosis, formication (feelings of bugs crawling under the skin), deterioration of oral health (“meth mouth”), hair loss, depression, increased risk of obsessive behavior, and reduced inhibitions.
Cocaine (White powder, paste or solidified)
Some negative short-term effects of cocaine use are restlessness, irritability, anxiety, panic, and paranoia. Other side effects include tremors, muscle twitches/tics, vertigo, constricted blood vessels, dilated pupils, increased heart rate, increased blood pressure, increased body temperature and decreased sexual function. The long-term effects of cocaine are chronic fatigue, headaches, abdominal pain, nosebleeds, weight loss, blood-borne diseases, heart arrhythmias, cardiac arrest, stroke, seizures, respiratory arrest, and death.
Ecstasy (MDMA)
The short-term effects of ecstasy are increased energy levels, distorted perception of time, nausea, muscle cramping, fever, sweating/chills, hallucinations, blurred vision, increased heart rate, increased blood pressure, facial tension, and feeling faint. Although there are no identified long-term effects, ecstasy seems to damage serotonin neurotransmitters which can cause depression, anxiety, insomnia and memory loss.
Psilocybin (Mushrooms)
Short-term effects are hallucinations, impaired judgement, paranoia, psychosis, anxiety, excessive sweating, dilated pupils, increased blood pressure and heart rate, blurred vision, tremors, coordination problems, anxiety, depression, nausea, loss of appetite, dry mouth, and sleep disturbances. The long-term effects are very similar to those of LSD.
LSD (Made from lysergic acid)
Some side effects include hallucinations, enhanced sensory perceptions, distorted sense of time, impulsive behavior, increased blood pressure/heart rate, increased body temperature, insomnia, dizziness, loss of appetite, dry mouth, excessive sweating and tremors. Some psychological risks of LSD are severe anxiety, panic attacks, paranoia, dissociation of body and mind, dissociation from reality, aggressive behavior and suicidal thoughts. Two possible long-term side effects after taking LSD are Persistent Psychosis and Hallucinogen Persisting Perception Disorder which are the effects of a bad trip that last weeks or months after the trip.
Mechanisms of Addiction
What is Addiction?
Addiction is a chronic disease of the brain with a compulsive seeking of the drug despite negative consequences.
Parts of the Brain and Circuits Related to Addiction
A binge/intoxication-related circuit is most likely involve actions with an emphasis on the ventral striatum and extended amygdala reward system, as well as dopaminergic and opioid inputs from the ventral tegmental area (VTA) and arcuate nucleus of the hypothalamus, respectively.
A withdrawal/negative affect-related circuit decreases in the reward function of the ventral striatum, but also the recruitment of brain stress neurocircuitry, including CRF and norepinephrine in the extended amygdala.
A preoccupation/anticipation (ie, craving)-related circuit is shown to have extended amygdala (for stress-induced reinstatement), as well as key afferent glutamatergic projections to the extended amygdala and nucleus accumbens, specifically from the prefrontal cortex (for drug-induced reinstatement) and the basolateral amygdala (for cue-induced reinstatement).
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Dopamine
- Dopamine is a neurotransmitter in the brain which controls movement, memory, pleasure, reward, sleep, mood and learning. The dopaminergic mesolimbic system, which is the role dopamine has in the brain, plays a significant role in the behaviors which help an individual act and survive. Drug use causes an increase of dopamine which has a much stronger effect of reward and pleasure then natural actions such as eating and sex. Too much dopamine can cause a person to feel nervous, irritable, and aggressive. These effects are caused by the tolerance which is built up when a person uses a substance daily. Tolerance causes feelings such as depression and anxiety because it takes much more dopamine to feel the effects.
Theories of Addiction
This theory explains how the use of one drug opens up a taste and desire to try other drugs while the personal risk associated with the drug is significantly decreased. This theory is controversial, however and has been debunked over time.
A rapid release of dopamine, a pleasure neurotransmitter, rushes into the brain and makes the person feel really good.
Research shows that genes are responsible for about half the risk for addiction whether or not the presence or absence of a substance is also a factor. Personal coping is also a factor of the genetics theory of addiction. At the same time, not everyone who has addiction in their genetic makeup will become addicted.
Changes In The Brain
Drug intake causes changes in the brain in a two stage process once a user starts taking a drug. The first stage begins when the user starts to take a substance more regularly and uncontrolled. This has a strong effect on the brain’s functions, especially the reward system with an overload of dopamine in the synapse. For example, with cocaine, the reuptake of dopamine is blocked which causes an increase of dopamine levels in the synapse. Dopamine is a neurotransmitter related to reward, its increase sends off signals of happiness whereas its decrease causes cravings for more of the drug to the neurons in the brain.
In the second stage, the brain starts to alter due to excessive drug use. When there is an abundance of neurotransmitters, this causes a decrease in the number of receptors. Therefore, the neurotransmitters in the synapse do not have a place to bind. Also, neurons reduce the production of neurotransmitters which in turn causes the brain to have having less receptors and neurotransmitters. When there is absence of the drug, the body feels withdraw when the neurotransmitter glutamate, which is the primary excitatory NT, sends signals of alterations and changes to the prefrontal cortex. These changes are what causes the brain to react the way it does to certain situations. An example of this is when a user stops taking a substance, the brain sends signals to the neurons in the brain which tells the user it needs more substance.
Limbic System
The limbic system is a complex neural network which is involved in integrating emotional responses and regulating motivated behavior and learning.
Hippocampus- establishment of long term memory and spatial memory
Amygdala- plays a central role in coordinating emotional responses
Nucleus Accumbens- plays a role in the reward system
Frontal Lobe– responsible for movement and executing planning
(Source: Psychopharmacology: Drugs, The Brain, And Behavior by Jerrold S. Meyer and Linda F. Quenzer)
Alcohol, cocaine, heroin, marijuana, and nicotine each have an effect on this system. They specifically effect the nucleus accumbens, which increases a release of the neurotransmitter dopamine. Dopamine makes the body have feelings of pleasures like euphoria and satisfaction, especially reward.
Hard Wired
- Drugs cause long term changes to neurons in the brain
- Connections to decision making, learning and memory become “hard wired”
- That is why it is hard for an addict to stop and change their behavior because it becomes so normal
- Some of these changes can never be reverted back to normal
- kills neurons that can never form again, even after the use of the substance is stopped
Image by Genetic Science Learning Center
This imagine shows the newly formed dendrites in a cocaine addict
Changes Due to Certain Drugs
- cocaine—deficits in cognitive flexibility
- amphetamine—deficits in attention and impulse control
- opioids—deficits in cognitive flexibility
- alcohol—deficits in working memory and attention
- cannabis—deficits in cognitive flexibility and attention
- nicotine—deficits in working memory and declarative learning
How Addiction is Formed: National Geographic
MRI brain scan of addict
- Yellow shows brain function, in the substance abuser there is less yellow
- Shows at some point → individual has no choice not to stop because it biologically changes their brain to its normal
- If you become sober, after 3 months the function starts to become normal again
Image by Brookhaven National Laboratory
Effectiveness of Treatment
Most treatment options are not tailored to the needs of the addicted individual. A lot of research has gone into finding out if individuals have certain alleles and genes that make them more susceptible to addiction. Gene discovery can expose mechanisms in the brain that are hereditary such as gene expression, brain structure and function, and overall behavior.
Multi-Component Treatment Strategies on Drug Addiction
- Decrease the reward value of the drug choice and increase the reward value of nondrug reinforcers
- Weaken the conditioned drug behaviors
- Weaken the motivational drive to take drugs
- Strengthen frontal inhibitory and executive control
Photo by: pixabay
A series of remissions and relapses can ensue after one passes the “honeymoon” phase of quitting drugs. Then the individuals either return to a soberer life or return to drugs. Frequent and chronic relapses occur because addiction is a genetic disease. A preventative treatment of addiction is detecting the effects of rare and uncommon alleles that are present in families. Detecting addiction alleles could also help in identifying the addictive agents in surroundings, such as culture, social policy, religion, economic status, trafficking, time, and space. Whole genome scans with contrast can detect and allow for a localization of chromosomes and further gene discovery. These discoveries can reveal mechanisms by which chronic drug exposure promotes stable changes in gene expression, brain structure, function, and behavior. Understanding how genetic and environmental influences to show how an addiction got this way may help in creating a specific treatment plan more the individual.
Addiction has the highest remission rate out of every psychiatric disorder. Most addicts quit without professional help. Studies have shown that addicts will quit for more practical and moral reasons than anything else. They want to be better parents, make their parents proud, or end any further embarrassment addiction has already caused them. Other reasons for quitting are medical problems, marital status (generally single people will remain addicted longer), if they have a higher income, and if they have spent more years in school. Financial and familial reasons are the highest percentage of why addicts quit drug use. Studies have shown, typically the onset of illicit drug use occurs at age 20, but most people are “ex-addicts” by age 30. Instead of quitting, sometimes addicts just switch drugs rather than quitting. A lot of these kinds of studies regarding addiction treatments are missing a big chunk of the population of addicts because some people still remain heavy drug users and refuse to cooperate with researchers because of their lifestyles, illnesses, or high mortality rate.
How Can We Improve The System?
Schedule of Drugs: On The Basis Of Its Effects On The Body
Schedule 1: Most harmful, high potential for abuse, no medical use
Heroin- Heroin produces 10x the amount of dopamine then the normal amount in the brain. It has long term effect on the prefrontal cortex like memory, decision making, ect when tolerance is built which causes extreme dependency.
Cocaine- Cocaine produces large amounts of dopamine in the brain which causes a feeling of reward. Regardless of how much of the drug is used or how frequency, increases risk that the user will experience a heart attack, stroke, seizure or respiratory (breathing) failure, any of which can result in sudden death.
Methamphetamine- Frequent abuse can cause a variety of symptoms to be exhibited, such as anxiety, confusion, insomnia, mood disturbances, and violent behavior. The brain is altered significantly with chronic use, impairing impairing learning and reducing motor speed. Some long term effect of methamphetamine are psychosis, paranoia, hallucinations, changes in the brain structure, and increased distractibility.
Schedule 2: Less harmful than Schedule 1, but still a high potential for abuse
Nicotine- Nicotine is one the most used drugs in the US and causes disease, disability, and death. Its high use is to due to its highly addictive property and how easy it is to access. Health issues include lung disease, cancer, affects
PCP- PCP has potent effects on the nervous system altering perceptual functions (hallucinations, delusional ideas, and confused thinking), motor functions (unsteady, loss of coordination, and disrupted eye movement), and autonomic nervous system regulation (rapid heart rate, altered body temperature regulation). This drug is also known to have mood altering effects causing some to become detached while others tend to become animated.
Schedule 3: Still harmful, but not as addicting as Schedule 1 and 2
LSD- LSD creates mental effects such as delusions/hallucinations, impaired perception, fear, anxiety, panic attacks, distortion of time/identity, flashbacks, depression, psychosis.
Ecstasy- People can become dependent on the drug causing long term effects of the mind and body, such as damage to neurotransmitters, depression, anxiety, memory loss, and insomnia.
Marijuana- Marijuana can affects a person’s judgement as well as the development of the adolescent brain and memory. It can also increase one’s heart rate, produce hallucinations, and create altered senses of perception.
Psilocybin Mushrooms- For physical effects, mushrooms produce symptoms of numbness, increased heart rate/blood pressure, and muscle weakness/convulsions. Mental side effects of mushrooms are a distortion of reality, altered sense of time, anxiety/panic attacks, and paranoia.
Schedule 4: Least Harmful
Caffeine- It acts as a central nervous system stimulant. When it reaches the brain, it causes alertness. It has no long term effects on the brain, but withdraw symptoms include headache, irritability and anxiety.
Pharmacological Treatments
Methadone – Targets the same part of the brains as Heroin does to relieve withdraw symptoms. Even though it has the possibility of being additive, it is not as harmful to the body as Heroin is.
Chantix- It is a nicotine replacement which prevent relapse for people who are trying to quit.
Vivitrol– Blocks the effects of the opioids at the receptor sites in the brain so the body does not crave them. This makes the withdraw symptoms less severe. This also works the same way for people with alcohol addiction by blocking receptors involved in reward.
In Conclusion:
We decided to classify these drugs in schedules based on the harmful impacts each substance can have on the body. We believe that medical providers, as members of the medical community, have the responsibility and obligation to provide care to anyone who is in need. This means that they are not permitted to discriminate or refuse to treat a person based on prior drug overdoses or other medical needs. In essence, we made this schedule the way we did because we believe that the addictiveness and harm on the body are best explained and identified in this way.
