How Science Has Revolutionized the Understanding of Drug Addiction

        For much of the past century, scientists studying drug abuse labored in the shadows of powerful myths and misconceptions about the nature of addiction. When scientists began to study addictive behavior in the 1930s, people addicted to drugs were thought to be morally flawed and lacking in willpower. Those views shaped society’s responses to drug abuse, treating it as a moral failing rather than a health problem, which led to an emphasis on punishment rather than prevention and treatment. Today, thanks to science, our views and our responses to addiction and other substance use disorders have changed dramatically. Groundbreaking discoveries about the brain have revolutionized our understanding of compulsive drug use, enabling us to respond effectively to the problem.
        As a result of scientific research, we know that addiction is a disease that affects both the brain and behavior. We have identified many of the biological and environmental factors and are beginning to search for the genetic variations that contribute to the development and progression of the disease. Scientists use this knowledge to develop effective prevention and treatment approaches that reduce the toll drug abuse takes on individuals, families, and communities.  Despite these advances, many people today do not understand why people become addicted to drugs or how drugs change the brain to foster compulsive drug use. This booklet aims to fill that knowledge gap by providing scientific information about the disease of drug addiction, including the many harmful consequences of drug abuse and the basic approaches that have been developed to prevent and treat substance use disorders. At the National Institute on Drug Abuse (NIDA), we believe that increased understanding of the basics of addiction will empower people to make informed choices in their own lives, adopt science-based policies and programs that reduce drug abuse and addiction in their communities, and support scientific research that improves the Nation’s well-being. 

                                    Why study drug abuse and addiction?
        Abuse of and addiction to alcohol, nicotine, and illicit and prescription drugs cost Americans more than $700 billion a year in increased health care costs, crime, and lost productivity. Every year, illicit and prescription drugs and alcohol contribute to the death of more than 90,000 Americans, while tobacco is linked to an estimated 480,000 deaths per year. (Hereafter, unless otherwise specified, drugs refers to all of these substances.)

        Babies exposed to drugs in the womb may be born premature and underweight. This exposure can slow the child’s intellectual development and affect behavior later in life.  Adolescents who abuse drugs often act out, do poorly academically, and drop out of school. They are at risk for unplanned pregnancies, violence, and infectious diseases.  Adults who abuse drugs often have problems thinking clearly, remembering, and paying attention. They often develop poor social behaviors as a result of their drug abuse, and their work performance and personal relationships suffer.  Parents' drug abuse often means chaotic, stress-filled homes, as well as child abuse and neglect. Such conditions harm the well-being and development of children in the home and may set the stage for drug abuse in the next generation.

                                                 What is drug addiction?
        Addiction is defined as a chronic, relapsing brain disease that is characterized by compulsive drug seeking and use, despite harmful consequences. It is considered a brain disease because drugs change the brain—they change its structure and how it works. These brain changes can be long-lasting, and can lead to the harmful behaviors seen in people who abuse drugs.  Addiction is a lot like other diseases, such as heart disease. Both disrupt the normal, healthy functioning of the underlying organ, have serious harmful consequences, and are preventable and treatable, but if left untreated, can last a lifetime.

                                                Why do people take drugs?
        In general, people begin taking drugs for a variety of reasons:

To feel good- Most abused drugs produce intense feelings of pleasure. This initial sensation of euphoria is followed by other effects, which differ with the type of drug used. For example, with stimulants such as cocaine, the “high” is followed by feelings of power, self-confidence, and increased energy. In contrast, the euphoria caused by opiates such as heroin is followed by feelings of relaxation and satisfaction.  To feel better- Some people who suffer from social anxiety, stress-related disorders, and depression begin abusing drugs in an attempt to lessen feelings of distress. Stress can play a major role in beginning drug use, continuing drug abuse, or relapse in patients recovering from addiction.
To do better- Some people feel pressure to chemically enhance or improve their cognitive or athletic performance, which can play a role in initial experimentation and continued abuse of drugs such as prescription stimulants or anabolic/androgenic steroids.
Curiosity and "because others are doing it." In this respect adolescents are particularly vulnerable because of the strong influence of peer pressure. Teens are more likely than adults to engage in risky or daring behaviors to impress their friends and express their independence from parental and social rules.

             If taking drugs makes people feel good or better, what's the problem?
        When they first use a drug, people may perceive what seem to be positive effects; they also may believe that they can control their use. However, drugs can quickly take over a person’s life. Over time, if drug use continues, other pleasurable activities become less pleasurable, and taking the drug becomes necessary for the user just to feel “normal.” They may then compulsively seek and take drugs even though it causes tremendous problems for themselves and their loved ones. Some people may start to feel the need to take higher or more frequent doses, even in the early stages of their drug use. These are the telltale signs of an addiction.  Even relatively moderate drug use poses dangers. Consider how a social drinker can become intoxicated, get behind the wheel of a car, and quickly turn a pleasurable activity into a tragedy that affects many lives.

                               Is continued drug abuse a voluntary behavior?
        The initial decision to take drugs is typically voluntary. However, with continued use, a person’s ability to exert self-control can become seriously impaired; this impairment in self-control is the hallmark of addiction. Brain imaging studies of people with addiction show physical changes in areas of the brain that are critical to judgment, decision making, learning and memory, and behavior control.  Scientists believe that these changes alter the way the brain works and may help explain the compulsive and destructive behaviors of addiction.

​                       Why do some people become addicted to drugs, while others do not?
        As with any other disease, vulnerability to addiction differs from person to person, and no single factor determines whether a person will become addicted to drugs. In general, the more risk factors a person has, the greater the chance that taking drugs will lead to abuse and addiction. Protective factors, on the other hand, reduce a person’s risk of developing addiction. Risk and protective factors may be either environmental (such as conditions at home, at school, and in the neighborhood) or biological (for instance, a person’s genes, their stage of development, and even their gender or ethnicity).

                                      How do drugs work in the brain?
        Drugs are chemicals that affect the brain by tapping into its communication system and interfering with the way neurons normally send, receive, and process information. Some drugs, such as marijuana and heroin, can activate neurons because their chemical structure mimics that of a natural neurotransmitter. This similarity in structure “fools” receptors and allows the drugs to attach onto and activate the neurons. Although these drugs mimic the brain’s own chemicals, they don’t activate neurons in the same way as a natural neurotransmitter, and they lead to abnormal messages being transmitted through the network.  Other drugs, such as amphetamine or cocaine, can cause the neurons to release abnormally large amounts of natural neurotransmitters or prevent the normal recycling of these brain chemicals. This disruption produces a greatly amplified message, ultimately disrupting communication channels.

​        Most drugs of abuse directly or indirectly target the brain’s reward system by flooding the circuit with dopamine. Dopamine is a neurotransmitter present in regions of the brain that regulate movement, emotion, motivation, and feelings of pleasure. When activated at normal levels, this system rewards our natural behaviors. Overstimulating the system with drugs, however, produces euphoric effects, which strongly reinforce the behavior of drug use—teaching the user to repeat it.

​        Our brains are wired to ensure that we will repeat life-sustaining activities by associating those activities with pleasure or reward. Whenever this reward circuit is activated, the brain notes that something important is happening that needs to be remembered, and teaches us to do it again and again without thinking about it. Because drugs of abuse stimulate the same circuit, we learn to abuse drugs in the same way.

        When some drugs of abuse are taken, they can release 2 to 10 times the amount of dopamine that natural rewards such as eating and sex do. In some cases, this occurs almost immediately (as when drugs are smoked or injected), and the effects can last much longer than those produced by natural rewards. The resulting effects on the brain’s pleasure circuit dwarf those produced by naturally rewarding behaviors.  The effect of such a powerful reward strongly motivates people to take drugs again and again. This is why scientists sometimes say that drug abuse is something we learn to do very, very well.

                     What happens to your brain if you keep taking drugs?
        For the brain, the difference between normal rewards and drug rewards can be described as the difference between someone whispering into your ear and someone shouting into a microphone. Just as we turn down the volume on a radio that is too loud, the brain adjusts to the overwhelming surges in dopamine (and other neurotransmitters) by producing less dopamine or by reducing the number of receptors that can receive signals. As a result, dopamine’s impact on the reward circuit of the brain of someone who abuses drugs can become abnormally low, and that person’s ability to experience any pleasure is reduced.
        This is why a person who abuses drugs eventually feels flat, lifeless, and depressed, and is unable to enjoy things that were previously pleasurable. Now, the person needs to keep taking drugs again and again just to try and bring his or her dopamine function back up to normal—which only makes the problem worse, like a vicious cycle. Also, the person will often need to take larger amounts of the drug to produce the familiar dopamine high—an effect known as tolerance.

        We know that the same sort of mechanisms involved in the development of tolerance can eventually lead to profound changes in neurons and brain circuits, with the potential to severely compromise the long-term health of the brain. For example, glutamate is another neurotransmitter that influences the reward circuit and the ability to learn. When the optimal concentration of glutamate is altered by drug abuse, the brain attempts to compensate for this change, which can cause impairment in cognitive function. Similarly, long-term drug abuse can trigger adaptations in habit or non-conscious memory systems. Conditioning is one example of this type of learning, in which cues in a person’s daily routine or environment become associated with the drug experience and can trigger uncontrollable cravings whenever the person is exposed to these cues, even if the drug itself is not available. This learned “reflex” is extremely durable and can affect a person who once used drugs even after many years of abstinence.

                                      Can addiction be treated successfully?
Yes. Addiction is a treatable disease. Research in the science of addiction and the treatment of substance use disorders has led to the development of evidence-based interventions that help people stop abusing drugs and resume productive lives.

                                                  Can addiction be cured?
Not always—but like other chronic diseases, addiction can be managed successfully. Treatment enables people to counteract addiction’s powerful disruptive effects on their brain and behavior and regain control of their lives.

                         Does relapse to drug abuse mean treatment has failed?
No. The chronic nature of the disease means that relapsing to drug abuse at some point is not only possible, but likely. Relapse rates (i.e., how often symptoms recur) for people with addiction and other substance use disorders are similar to relapse rates for other well-understood chronic medical illnesses such as diabetes, hypertension, and asthma, which also have both physiological and behavioral components. Treatment of chronic diseases involves changing deeply imbedded behaviors, and relapse does not mean treatment has failed. For a person recovering from addiction, lapsing back to drug use indicates that treatment needs to be reinstated or adjusted or that another treatment should be tried.

           What are the principles of effective substance use disorder treatment?
       Research shows that combining treatment medications (where available) with behavioral therapy is the best way to ensure success for most patients. Treatment approaches must be tailored to address each patient’s drug use patterns and drug-related medical, psychiatric, and social problems.  Behavioral treatments help engage people in substance use disorder treatment, modifying their attitudes and behaviors related to drug use and increasing their life skills to handle stressful circumstances and environmental cues that may trigger intense craving for drugs and prompt another cycle of compulsive use. Behavioral therapies can also enhance the effectiveness of medications and help people remain in treatment longer.

        Gaining the ability to stop abusing drugs is just one part of a long and complex recovery process. When people enter treatment for a substance use disorder, addiction has often taken over their lives. The compulsion to get drugs, take drugs, and experience the effects of drugs has dominated their every waking moment, and abusing drugs has taken the place of all the things they used to enjoy doing. It has disrupted how they function in their family lives, at work, and in the community, and has made them more likely to suffer from other serious illnesses. Because addiction can affect so many aspects of a person’s life, treatment must address the needs of the whole person to be successful. This is why the best programs incorporate a variety of rehabilitative services into their comprehensive treatment regimens. Treatment counselors may select from a menu of services for meeting the specific medical, psychological, social, vocational, and legal needs of their patients to foster their recovery from addiction.


​             Common Misconceptions About Addiction

Addicts Have a Good Time

        For people who can have a drink or two and leave it at that it’s easy to assume alcoholics have the same experience they do, just all day long. They may imagine, even envy, a carefree day of mild to moderate intoxication.  In truth, addiction - having to stay drunk/high all the time just to feel normal, just to avoid withdrawal is a life of daily worsening hardships involving brutal physical, emotional and psychological repercussions from which there are few respites, save unconsciousness. The old saying that addiction is slavery is true. Addicts are prisoners to continuous drug use and the terrible things they have to say and do to obtain enough to get them through every day. There are no vacations from addiction.  No matter how much they deny it, every late-stage addict knows at some level that he or she can’t stop using regardless of how hard they try. In my descent into deep addiction, there were precious few fleeting moments of fun. Realizing you’ve lost self-control is baffling and terrifying. This horror permeates nearly every thought and action, every moment of every day and it’s a terrible life.
                                                            Addicts Are Stupid, Lazy People
        People who don’t know that brain changes prompt addiction’s compulsive drug use may presume addicts are just too stupid to know better, but addicts aren’t stupid. They have something akin to selective blindness. They believe, wrongly but wholeheartedly, that they need drugs just to survive.  It isn’t a belief they make up out of thin air, it has a biological basis. Specifically, the brain develops tolerance to drugs, which worsens over time and eventually requires a base level of constant intoxication to stave off the disastrous consequences of withdrawal. Addicts will do crazy things to avoid detoxing but they do them in service of a disease they can’t control.  Addicts also aren’t lazy, they’re actually intensely motivated people but that drive is limited to satisfying their most compelling need; getting enough drugs every day to stave off withdrawal, it’s not easy to do In fact, it’s exhausting.
        You would not believe how much time and effort it takes to insure you have enough drugs to make it through today, tomorrow and the next day. Imagine for a moment that you had to buy at least a quart of alcohol every day while simultaneously concealing it from everyone around you, every day no days off. Also imagine you were intensely attuned to hiding how much you’re buying so you have to rotate among half-a-dozen stores. And you have to dispose of the bottles in a way that doesn’t blow your cover — alcoholics don’t use their own garbage or recycling bins, they farm out the evidence.  Most addicts expend such substantial efforts feeding their addictions that when they get sober they find they have a lot of dangerous free time. One of the challenges of early sobriety is to use that time constructively rather than destructively like they used to.
                                                    Addicts Lack Willpower
        Although it’s true that most addicts lack the willpower to overcome addiction on their own, that’s a symptom of the brain changes associated with addiction, not its cause. Addiction is a disease which, due to the progressive nature of tolerance, is characterized by accelerating compulsive drug use despite worsening personal, physical, social and psychological consequences.  Failing to stop isn’t driven by a mere lack of willpower. It’s driven by changes to the structure and function of brain cells that have morphed into a “new normal” requiring a base-level of intoxication to function. Neuroscientists say that while people may start out using drugs to get high, tolerance leads addicts to continue to take drugs to avoid the terrible lows of withdrawal. The motivational power of the fear of detox outweighs all of the rational reasons, all willpower that ought to convince an addict to stop but rarely can. 
                                   Forced Treatment Fails: Addicts Have to Want Help 
        Addicts don’t have to want help in order for treatment to work. In fact, most addicts are in denial and don’t think they need it. What’s required is that they become willing during treatment.  Immersion in a therapeutic community eventually whittles away any objections.  People become willing because of the love and care that is given in good treatment centers. I see this happen over and over. Take a drug addict, remove the drugs, care for him in a therapeutic setting, and even the most resistant can become willing. That doesn’t mean they’ll succeed, but it’s a start.
Punishment Is the Best Model to Make People Stop Using Drugs
        Threats of punishment like arrest and incarceration, hazards rational people would avoid, are largely useless in getting addicts to quit. That’s because it’s a disease in which the emotional motivational need for drugs far outweighs the threat of the negative consequences of drug use. This has a biological basis: the balance between the brain’s competing emotional and rational systems is altered by drug abuse, resulting in over-valuing the short-term emotional payoff of continued drug use at the expense of longer-term rationality.
        As Dr. Alan Leshner, at the time the Director of the National Institute on Drug Abuse, wrote in a 1997 issue of Science Magazine, “If the brain is the core of the problem, attending to the brain needs to be a core part of the solution. Understanding that addiction is a consequence of fundamental changes in brain function means that a major goal of treatment must be either to reverse or to compensate for those brain changes.” Criminal-justice strategies to curb addiction “are missing at least half of the issue,” wrote Leshner. Incarceration disregards the essence of addiction: “If they [addicts] have a brain disease, imprisoning them without treatment is futile.”
     For every recovering addict that I’ve known, except two or three who were able to get sober on their own, the key to sobriety has been immersion in a therapeutic community. And, as I know from many years in addiction, county jails and state and federal prisons are the opposite of therapeutic communities.