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But we must ask whether they are necessary components of addiction — or whether addiction would persist even in their absence. In the s, researchers made a surprising discovery. Food , sex and drugs all appeared to cause dopamine to be released in certain areas of the brain, such as the nucleus accumbens. However, this idea has since been debunked. The brain does have pleasure centers , but they are not modulated by dopamine. These rats lost the urge to eat but still had pleasurable facial reactions when food was placed in their mouths. This makes us crave more drugs.

In my own research , we looked at a small subregion of the amygdala , an almond-shaped brain structure best known for its role in fear and emotion. We found that activating this area makes rats more likely to show addictive-like behaviors: narrowing their focus, rapidly escalating their cocaine intake and even compulsively nibbling at a cocaine port. Opioids — such as oxycodone, percocet, vicodin or fentanyl — are very effective at managing otherwise intractable pain.

Yet they also produce surges in dopamine release. Most individuals begin taking prescription opioids not for pleasure but rather from a need to manage their pain, often on the recommendation of a doctor. Any pleasure they may experience is rooted in the relief from pain.

However, over time, users tend to develop a tolerance. The drug becomes less and less effective, and they need larger doses of the drug to control pain. This exposes people to large surges of dopamine in the brain. As the pain subsides, they find themselves inexplicably hooked on a drug and compelled to take more. These cues can include drug paraphernalia, negative emotions such as stress or even specific people and places.

These changes in the brain can be long-lasting, if not permanent. Childers, PhD; Marian W. Fischman, PhD; John A. Howlett, PhD; Chris E. Kuhar, PhD; A. A special note of thanks to Dr. Howlett, who led us to our publisher. These projects first led us to break down complex information about brain function into terms simple enough for parents and educators to teach children. Their enthusiastic response to this effort encouraged us to write this book. Individually, Dr. Friedman thanks all the scientists, teachers, treatment providers, students and others whose intellectual curiosity and desire to understand what drugs do to us helped him develop his ideas about drugs and the brain.

Similarly, Mrs. Interactions with people who want to know precisely how addiction develops have challenged both of us and helped us learn how to present this information in ways people can understand. Finally, our thanks to our families for their patience and forbearance during the writing process. Or how free will is related to either the brain or the mind? Or whether something that affects your brain can change your mind or alter your ability to choose what to do? To understand how drugs of abuse cause addiction, all these concepts become important.

The Brain: The portion of the central nervous system enclosed within the skull. It includes all the higher nervous centers receiving stimuli from the sense organs. The brain interprets and correlates these stimuli to create your thoughts, feelings, and movements. It is the organ of the mind. The Mind: The element, or complex of elements, that allows a person to perceive, think, feel, reason, and will. The mind is the manifestation of consciousness. Free Will: The ability to choose and decide, the freedom of humans to make choices that are not determined by prior causes or by divine intervention.

Our brain keeps our body functioning, our mind is where thinking and feeling occur, and free will allows us to integrate thoughts with feelings to make choices and decisions and to act on those decisions. Most people view the interactions of the mind and the brain as merely unfathomable, whereas the question of how free will leads to action is an abyss that logic and reason cannot begin to bridge.

For ages, people have also been fascinated by drugs that alter the mind, and ultimately impair free will. How do drugs do that? How do people become different under the influence of drugs? What makes these differences come about? Once they try these drugs, many people keep using them, in spite of problems that often develop with increasing use. Moreover, some of those who keep using drugs over an extended period of time become addicted. How does that happen? Neuroscientists have combined the methods of psychology, biology, chemistry, computer science, and anything else they could get their hands on to explore the workings of the brain.

They have brought about an explosion of knowledge. As a result, our ability to think about drugs, the mind-brain interaction, and free will is changing. A striking irony has emerged from this new knowledge: As drug use progresses to abuse and addiction, drugs rob people of the very free will they exercised when they first decided to use drugs. How this happens is something that neuroscientists are now beginning to understand. But because the language of science is highly technical, few other people have had access to this knowledge. This book explains what neuroscientists know about drugs and the brain in language everyone can understand.

You eat and drink so that you can survive. Eating and drinking make you feel good. You have sex so that your species can survive. Sex, too, makes you feel good. The feelings of pleasure that result when you accomplish survival-oriented tasks are caused by the release of specific neurochemicals within this circuit, called the brain reward system. Your brain uses these feelings to teach you to repeat these behaviors. The cells in your brain communicate by releasing neurochemicals.

In some parts of the brain, drugs actually send false messages. In other parts, they weaken or intensify real ones. But no matter how they disrupt communications in other parts of the brain, nearly all drugs of abuse mimic the actions of the neurochemicals that make people feel pleasure when their brain reward systems are activated. Because of this, drugs actually teach people to use more drugs. Drugs have other effects. They produce tolerance, meaning that after a period of use, people need more of the drug to experience the same pleasure they felt at first use.

So, at the same time that drugs are using powerful brain circuits to teach people to repeat drug-taking behaviors, the brain and body are responding by adapting to the presence of drugs and causing drug users to take increasingly larger doses to get high. In other words, as drug tolerance develops, many users escalate their drug doses, setting the stage for the development of physical dependence and later, if abuse continues, addiction. As drug use progresses, the brain, our master teacher for survival, must instruct according to the dictates of the intruder that has taken over its classroom.

The more that drugs dominate this classroom, the closer people move toward addiction. And the closer people move toward addiction, the more free will they forfeit.

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The brain uses a second form of instruction, which not only helps to move people toward drug addiction, but keeps them there when they attempt to stop using drugs. Anyone who has tried to cut down or quit smoking cigarettes will recognize this teaching method. Drug users gradually learn to associate neutral behaviors such as talking on the phone or driving a car with drug-taking, like smoking a cigarette. Through that window they are seeing how our brain acts as the seat of our thoughts and feelings and how it controls our behavior.

Drugs change behavior by changing the way the brain works. Our emerging understanding of how drugs do this has enormous implications. It forces us to reexamine how we view drug addiction, to reconsider how we see ourselves, and even more profoundly to re-conceptualize the brain, the mind, and free will. To explain how drugs change the brain and produce addiction, we will follow the histories of several people whose involvement with drugs ranges from initial use to full-fledged addiction.

Some are addicted when we meet them. Others may not become addicted. Most will. Unlike the people whose letters appear in the preface, the drug users we are about to introduce are not real people, but composites we have created. They are based on the interactions we have had with thousands of drug users and their families. After finishing the joint, Neil and Michelle hopped into the car and headed for the dead-end road near the bay.

Lots of young people gathered there when their parents were at home. Neil and Michelle sat entwined in the front seat of the car. They kissed for what seemed like forever, and Neil could not believe how good it felt. He had kissed Michelle before, but this was different. Must be the pot, he told himself. Neil was really getting into it when suddenly a harsh, bright light flashed at them through the fogged-up back window. The police!


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They both panicked. They were stoned, and Neil still had that other joint in his pocket. As he turned onto the winding road that led back to town, Neil could feel his heart pounding. He had trouble judging the distance and speed of oncoming cars. He kept going too fast or too slow. When Neil tried to look into the rear-view mirror, he drifted toward the other side of the road into the path of an approaching car.

The car stopped abruptly and stalled. They were stuck. No way could he finish it by morning; he was too tired to stay up. But now, his problems were over. He had copped some coke from a classmate, and he knew he could stay up all night and write. He tested his new stash. It was good stuff.

Understanding Drug Use and Addiction

His nose went numb almost immediately, and he could taste the bitterness as those first few snorts ran down the back of his throat. In seconds, he felt that familiar light go on inside his head. He was more alert, more confident, smarter. He would get an A! Chris started writing. It was hard to keep a good train of thought, but his confidence grew with each hit he took.

One inspired thought after another flew around in his brain. It was all he could do to get his thoughts down on paper. It was all he could do to sit still. This was going to be excellent. His tongue ran in and out of his dry mouth. He was going to send this to The New York Times! He jumped up and down out of his seat as he typed. He paced around the room. He would be a Rhodes scholar! He got more and more anxious. A creaking noise on the back stairs really annoyed him. Then his coke ran out. He had finished the paper. He ran spell-check and grammar-check, and printed the sucker….

Chris was stunned when he got his paper back the following week. That idiot teacher had always had it in for him! Then he read his paper. The beginning was okay. It presented a couple of good arguments, but the paper was disorganized, repetitive, and—he just had to admit it—some parts were downright stupid.

The sentences were strung together in a random order. Now what would he do? Neil, Michelle, Chris, and the other drug users you will meet in this book are using drugs that affect the most important organ of their bodies—their brain. Your brain has many parts, and each part performs a different function. Throughout this book, we will focus on a key part, the brain reward system, on which drugs of abuse exert their most important effects.

This part of your brain releases neurochemicals that make you feel good when you do the things you need to do to survive eating, drinking, having sex, and so on. Drugs are false messengers that produce pleasure by either weakening or intensifying the neurochemicals that normally activate the brain reward system or by replacing those neurochemicals and activating the system directly. They do this gradually by changing the way the brain works. The changes occur because the brain slowly adapts to the presence of drugs and their effects.

They use them because drugs first produce pleasure, or relaxing, short-term effects. The cocaine that Chris used is a good example. Although cocaine produces feelings of pleasure, it also alters perception, judgment, and thinking and has powerful effects on mood. In this instance, cocaine gave Chris a false sense of confidence.

Chris is lucky. Moreover, because of the intense craving that both forms of the drug create in the brain, they can cause very powerful addictions. Some drugs not only make people feel good, they also make them feel less bad, that is, they produce mild euphoria and relieve negative feelings. These drugs act on the brain to reduce anxiety, allay stress or relieve other negative feelings. If you were to ask Neil and Michelle why they smoke, they would say for the thrill of it.

But they also took the drug to overcome the anxiety that emerging sexual feelings often produce in adolescents and sometimes in experienced adults, even though these feelings are not new. Neil and Michelle are relatively new to drug use. Whether they stop using altogether or progress to more intensive use will depend on a number of factors, which we will explore as we examine how drugs teach the brain to take more drugs. God, she was going to miss Barry. Five, maybe six cans. A six-pack! But why not? But not Allison and Barry, even though they came close once or twice.

She had made the decision to postpone having sex, at least until she was through high school. First, it was her choice, which she decided after a great deal of thought and soul-searching. Second, it was way too embarrassing to get protection. Or, worse, carry condoms around in her purse.

What if her mother saw them—oh, God—or her father! Her decision not to have sex had been easy…until she met Barry. Oh, God! The six-pack that Allison drank impaired the function of her cerebral cortex, the part of her brain that allows her to exercise good judgment. She did something she would not have allowed herself to do if she had been sober, and she violated a code of behavior she had established for herself and adhered to until that night on the beach.

The drug can also cause serious long-term changes, including addiction, permanent memory loss, liver disease, and many kinds of cancer. These long-term changes occur when people gradually increase the amount of alcohol they drink as they develop tolerance to it, become physically dependent on it, and eventually become addicted to it. Not everyone who drinks becomes addicted. In clear contrast to the alcoholic, many people can drink moderate amounts of alcohol throughout their lives and experience few if any problems.

Henry Henry felt lucky. He had scored some of the purest heroin that Jake, his dealer, ever had. Just smelling the glistening white powder started to make him feel high and brought on a tremendous desire to shoot up right there in the middle of the street. But somehow he made it home. Henry knew something was wrong even as the rush hit him, and he tried to get up and walk out of the bathroom. He fell against the door and knocked it open, falling to the floor in front of his startled wife.

His breathing was slow and shallow. Deeply frightened, she called By the time they got Henry to the emergency room, the paramedics had already started to perform CPR [cardiopulmonary resuscitation]. The resident made a quick decision and administered naloxone. In a few moments, Henry started to breathe again and the blueness disappeared from his lips. Soon he was sitting up, asking to go home. An antagonist is a drug that blocks the effects of another drug. In Chapter 5, we will explain how antagonists work in the brain to block the effects of drugs and how they can help addicts recover.

Henry is addicted to one of the most severely addictive classes of drugs known to man, opiates. After opiate addiction becomes firmly established, withdrawal symptoms are so pronounced and craving for the drug is so powerful that few addicts succeed at recovering without experiencing several relapses before they reach their final goal, if they can reach it.

Because of its power, scientists have studied opiate addiction longer than they have studied addiction to other drugs. As a result, much is known about opiate addiction.

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Another reason why opiates have fascinated scientists is that throughout history opiates have been the most potent pain relievers known to man. Scientists have naturally focused on these drugs in a dual effort to help addicts overcome an addiction that is so powerful it often seems intractable, and, at the same time, to find more effective analgesics.

As a result, we know more about how opiates act on the brain than we know about most other drugs of abuse. In fact, the breakthrough that accelerated research on drugs and the brain occurred during a search to try to understand how opiates work on the brain.

This search led to the discovery of a unique set of molecules in the brain, called opiate receptors. Opiates attach themselves to these receptors to exert their effects. The discovery of the opiate receptor in the early s ignited an explosion of knowledge that has continued ever since. Two hours were left before Sybil had to leave for her flight.

Time enough to finish her speech. Her bags were packed and in the car. Only half a pack left.

Sue Rusche (Author of False Messengers)

They were right. Everyone she knew had quit. She was the only one left who still smoked.

How addiction changes your brain

One day soon, she told herself, pushing the button for line 3. I want you to come in. Too alarmed to hear his answer, she cut it off. Dear God, what could be wrong? At 48, she was at the height of her career, with a husband she loved, kids safely launched, one in college, one at work. She grabbed her laptop—she could finish her speech on the plane—and hurried down to her car….

She could hardly get the words out. Best lung man in the city. Each word hit her like a slap. Her addiction is not unusual: the surgeon general states that 9 out of 10 people who smoke are addicted. Sybil has been addicted to nicotine most of her life, and she certainly needs it to function normally. Each time she inhales, the cigarette smoke she draws in delivers nicotine to her brain.

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Unfortunately, it also delivers other poisonous chemicals to all parts of her body. Over time, these chemicals help to create heart disease, lung disease, and an astounding array of cancers throughout the body. Now these changes may have led to lung cancer. Your brain enables you to think, to plan, to imagine, to dream, to create, to form new relationships and sustain old ones, to be everything you want to be, and to do everything you want to do in life. It also manages your body functions and is the source of all of your thoughts and feelings.

It enables you to make choices and decisions and to plan and carry out your movements so you can act on those decisions. In short, it governs how you behave. While drugs of abuse may affect any organ in the body—and different drugs can affect different organs—the one thing that all drugs have in common is that they affect the brain. When we consider what risks drugs present, the most serious ones all result from a primary effect on the brain. If a person becomes addicted, it is because of the way the drug changes the brain.

As we follow the drug users we have introduced here, we will explain how the drugs they are taking change the way their brains process information and, as a result, change and gradually gain control of their behavior. Because drugs change the brain directly, they affect everyone who uses them—man or woman, black or white, rich or poor, young or old. Ultimately, if drugs are used long enough, the changes they produce can rob people of their free will.

You live in a complex, ever-changing world. Your brain must keep you alive and functioning effectively in this world. For instance, your brain tells your heart to beat at a speed that is healthy for you and tells your lungs to supply you with oxygen to keep you going. It also makes it possible for you to see, hear, and feel what is taking place around you and then uses this information to guide your actions. Your brain must constantly monitor them so that you can constantly adapt to them. For instance, getting up from a chair changes your heart rate.

Actually, every movement of your body and head changes the information coming in through your eyes, ears, and skin. Your brain needs to decipher this barrage of information so that it can help you decide which of the things going on around you is most important and then deal with those things effectively. A normal brain easily does all these things at once, although most of us are rarely aware of concentrating on more than one.

Driving involves many parts of your brain. To most people, driving seems pretty mundane. But only the most powerful computer could carry out any one of the different tasks you must accomplish to drive, and no computer has yet been designed that could combine all those tasks to drive a car. The rules that govern its organization evolved along with the brain itself. One of these rules is particularly useful to consider, because it makes it easier to understand how drugs act on the brain. This rule, called localization of function, says that specific places in your brain carry out specific functions of your brain.

For example, your brain directs the information coming from your eyes to a region toward the back of your head Fig. This part of your brain, appropriately called the visual cortex, receives information only from your eyes and does nothing else but analyze what you see. Without the visual cortex, you could perceive nothing of the visual world, even if your eyes were healthy and working properly. Another region, farther forward in your brain, called the somatosensory cortex from the Greek somato meaning body , processes information coming from your muscles, joints, and skin.

It gets information only about what you feel on your body surface and in your muscles and joints. This information, which is very important for driving, is called kinesthetic information from the Greek kinein to move. It tells you how your various body parts are oriented in relation to each other so that you can move them accurately.

Kinesthetic information can tell you how the angles of your wrist, elbow, and shoulder change as you turn the steering wheel of your car or shift gears. Thus, these two different kinds of information—one about what you see and the other about your skin, muscles, and joints—is directed to two different regions that process and perceive them independently of each other.

Another part of your brain, the motor cortex, eventually combines these two kinds of information so you can generate accurate movements just when you need them. Each major region shown here consists of many cortical fields. The visual cortex may contain several dozen by itself. Different functions take place in different parts of your brain because information is directed with great precision.

Because your brain sends information to exclusive regions, the kind of information it receives actually determines what that region can do. This is why you see stars, for example, when you get hit in the eye. That blow is hard enough to activate the unique nerve cells in your eye that ordinarily have the job of sending visual information to the brain. These specific nerve cells change light into a special set of coded signals that your brain can understand, but they are sensitive to pressure as well. Every day, these cells transmit billions of bits of information about light, and your brain always interprets information coming in from these cells as if it were light it almost always is.

So, even if pressure turns these cells on, your visual cortex still interprets this information as if it were created by something you saw. So far, we have spoken of the visual cortex and the somatosensory cortex as if they are each single structures. This is not so. Rather, each of the broader areas of the cortex that encompasses the visual and somatosensory cortex are subdivided into smaller parts that do detailed work on sensory information.

Each of these subdivisions is called a cortical field and has its own specialty. One cortical field analyzes shape, another analyzes color, and a third analyzes location or motion. In humans, and some other animals, one cortical field is specialized to analyze faces. A man who had an injury to this particular cortical field in his brain could not recognize his own wife from a photograph, but easily recognized her from her voice.

These cells are organized into thousands and thousands of groups. In the cerebral cortex, the groups are called cortical fields. Everywhere else in the brain, they are called nuclei. No matter what they are called, each group of nerve cells concentrates on a small aspect of a bigger job.

To get the big job done, all the relevant cortical fields or nuclei work simultaneously on their own small parts of that job. Computer scientists call this parallel processing. A construction crew might simply call it teamwork. To understand how your brain divides up work to get it done efficiently, you can compare the way your brain handles information with the way a construction crew builds a house.

For instance, a crew consists of many different kinds of craftsmen. Each kind of craftsmen has a special skill and performs just one kind of job. Similarly, although your brain contains many cortical fields and nuclei, each one handles just one kind of information. Also, craftsmen often work in only certain parts of a house. In your brain, the rule of localization of function determines that specific places always found in the same part of the brain carry out specific functions. Finally, much of the crew works on a house at the same time to get the job done faster.

Cortical fields and nuclei all work on incoming information at the same time. Plumbers, electricians, and carpenters do their special jobs simultaneously so they can build a house more rapidly. And because the craftsmen in each group are experts at their own craft, the whole job gets done more skillfully. In addition, plumbers work only with pipes, electricians work only with wires, and carpenters work only with wood. The kind of materials each craftsman works with actually helps define his job.

In the same way that materials help to determine what each craftsman may do, the kind of information a certain brain region receives helps to determine its job. Like craftsmen, the specific regions of your brain that handle these tasks specialize in carrying out just one function. For example, you are driving to the supermarket to buy food for a special dinner you are going to prepare for important guests. Therefore, your brain must control all the different parts of your body that keep you awake and alive.

At the same time, your brain must prevent your bodily needs from interfering with your driving. It cannot, for example, let you fall asleep at the wheel or let you run out of oxygen because you stopped breathing. While your brain attends to these and other bodily functions, it also helps you perform other tasks important to driving. You have to see and react to oncoming cars, find the right streets, and sometimes react to unexpected emergencies.

You have to control the car under changing traffic conditions. When driving conditions are easy, you may do all these things thoughtlessly, but when they become more difficult you have to focus your attention. All this requires processing a great deal of sensory information—mostly visual and kinesthetic—and turning that information into commands to your muscles so they can control the car properly and get you to your destination. When you reach the supermarket, you must make a left turn in heavy traffic to get into the parking lot.

You need to judge the speed and distance of oncoming cars, calculate how long it will take to cross the traffic lanes, and switch your foot from the brake to the gas pedal to get the car moving. If you are driving a car with a manual gear shift, you have to depress the clutch with your left foot as you control the gas with your right, steer with your left hand, and shift gears with your right hand. Four things at once!


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If you had to think about each one separately, you would have a tough time. Remember how hard it was to do this when you were first learning to drive? You had to concentrate very hard to do all these things, and you probably did not always succeed at getting them just right. He had let out the clutch too quickly, and the truck suddenly lurched forward and died.

Because the truck was bigger than any of the oncoming cars, they all stopped until he could get the truck out of their way. He eventually learned how to use the clutch and has no recollection of ever stalling in traffic since then. Like most adults, he now makes all these driving-related movements smoothly, easily, and with little mental effort. His brain does all the work for him. While your brain takes care of all the sensory and motor jobs directly related to driving, it does other things as well.

You may be talking on a car phone, turning the car radio to the stations you like rather than the stations set by the kids or your spouse, or trying to figure out a problem you have at work. All this goes on simultaneously while you drive. And you can do all these things at once because your brain divides up the work into small jobs and distributes the information needed to perform each one to the pertinent specialized regions.

Finally, your brain has one more job to do for you as you drive to the supermarket. It monitors your thoughts, memories, needs, and wants and creates the emotional and motivational context for all of your activities. Are you nervous about this important dinner? Are you late? Will there be fresh tomatoes in the produce section for your spaghetti sauce, or will you have to change the menu at the last minute? They all influence how you behave. And they can influence how you drive. For instance, if you are in a good mood, have plenty of time, and have ordered the key ingredients including fresh tomatoes ahead of time, you can relax and be a courteous, defensive driver.

But if you had a fight with your kids the radio stations they set just make you more angry and you are late and running out of time to prepare the meal, you are likely to be in an entirely different mood. This mood will affect how you drive. You may be tense, impatient, distracted, and not particularly courteous. You may even be an aggressive, offensive driver, at least for this trip to the supermarket. You may charge through a smaller gap in traffic than usual, causing the oncoming cars to slow down quickly.

Our brains create emotional and motivational aspects for our lives that can profoundly affect the way we handle our sensory and motor tasks. By doing this you can learn much about the way your brain is organized and thus lay the foundation for understanding how drugs work. A part of your brain called the brain stem has primary responsibility for these needs Fig. Your brain stem is a relatively primitive brain structure that starts where your spinal cord enters your head. All vertebrate animals i. Their brain stems look pretty much like ours and do pretty much the same things.

She rarely does what we ask her to do anymore. I am a year-old nurse with a year-old mother who is an alcoholic. She was hospitalized with short-term memory loss last week, after taking a tranquilizer, drinking two beers before work and eating no breakfast. Today, I left my job 2 hours early and drove 25 miles to get to her, because she couldn't remember her name or even what day it was. She resented my coming and lied to the doctor about her alcohol use, which begins every day before work.

My father died from alcoholism. I do not drink and feel totally alienated from my family. I want to fire my mother from my life forever. I don't want to care any more. An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.