Drug Addiction Research Paper

2. Why People Take Drugs

To fully understand the phenomenon of addiction, we need to have a thorough understanding of why people take drugs in the first place. Although we know some of the initial reasons why people take drugs—to modify their mood, perception, emotional state, or to self-medicate in an effort to cope with their problems—no one single underlying factor determines which individuals are more or less likely to abuse drugs and which will later become addicted to drugs. An individual’s vulnerability to becoming addicted to drugs is dependent on a number of complex factors, including a variety of genetic, biological, emotional, cognitive, and social risk factors.

Researchers have identified many of the risk factors that increase the probability that someone will develop drug problems. These factors can be found at the individual, the family, peer group, and at the broader community level. Researchers have also identified many of the protective or resiliency factors that protect individuals from developing drug-related problems. An individual’s vulnerability to becoming a drug user and later an addict is likely to be due to environmental and genetic factors interacting in some, as yet, unknown way. We also know that regardless of the reason for initial drug use, continued use can lead to neuroadaptation in brain reinforcement circuits.

Clear evidence exists demonstrating that almost all drugs of abuse have effects on brain circuitry involved in the control of motivated and learned behaviors. Although each class of drug may have its own specific mode of action, in tracing the pathways through which a variety of drugs exert their effects; certain commonalities for all drugs of abuse have emerged. This evidence originated from studies in animals (Weiss 1996, Wise and Bozarth 1981) and is being confirmed in humans with recent developments in brain imaging techniques. Anatomically, the brain circuitry principally involved in most of the actions of the major addictive drugs is the reward center or the mesolimbic pathway. This pathway consists of cells (mesolimbic neurons) that originate in the ventral tegmental area (located in the middle of the brain) that terminate and signal other cells in distant brain areas.

These cells (like all neurons) do not actually touch each other but are separated by specialized gaps called synapses. Neurons communicate with each other via chemical messengers referred to as neurotransmitters, which cross the synapses. In the case of mesolimbic neurons, the neurotransmitter used in the communication process is dopamine. It is at the synapse that drugs of abuse disrupt the normal communication process among neurons. Scientists have found that all drugs of abuse cause an increase in dopamine levels in the brain’s reward pathway. Activation of this reward system appears to be a common element in the reinforcement of drug-taking behaviors. Increased dopamine levels are associated with the feelings of euphoria and reward that are often associated with drug use. Researchers are also finding that the dopamine system may help play a role in determining what makes some individuals more susceptible to addiction than others (Volkow et al. 1999). Through the use of neuroimaging, researchers at Brookhaven National Laboratory have found that individuals who have higher densities of dopamine receptors before any drug exposure, report having a pleasant response to a mild stimulant; whereas individuals with lower dopamine 2 receptor levels report having unpleasant responses to the same mild stimulant. These findings are in concurrence with studies in laboratory animals indicating that dopamine receptors mediate reinforcing responses to drugs of abuse. Not only does this finding suggest that an individual’s resting brain chemistry may predispose how he or she responds to different drugs of abuse, but it potentially helps to predict who will develop drug problems. The finding also serves as a critical piece of information to help facilitate the development of more effective prevention and treatment approaches.

3. The Transition From Drug Abuse To The Disease Of Addiction

The fact that addiction is tied to changes in both brain structure and function is what makes it fundamentally a brain disease. For many of the individuals who do not have an initially negative reaction to their first drug-administration, continued repetition of ‘voluntary’ drug taking begins to change—often undetectably—into compulsive drug taking, ultimately to the point where the behavior is driven by an overwhelming craving for the drug. The compulsion to get and use drugs becomes the most powerful motivator in a person’s life. It is at this stage that addiction becomes a chronic disease with relapse and remission. We often make the analogy that a methaphorical switch in the brain is thrown that changes an individual user abuser into a drug addict. The individual changes from a totally voluntary drug user into a compulsive, often uncontrollable drug user.

Although research has significantly advanced our understanding of the behavioral, biological, and molecular factors which underlie initial drug use and the actual state of addiction, we are lacking a thorough understanding of the mechanisms that are involved to explain what literally occurs when an individual transitions from a voluntary drug user to an addict. We know that the full course of a typical drug use disorder evolves through a whole series of transitions over a period of years that begins with the initial onset of drug use, the maintenance or continuation and eventual escalation of use, movement from one drug class to another, escalation within that drug class, and multiple drug use (in many cases). Typically once treatment is provided, the individual discontinues drug use, but often relapses even after long periods of abstinence (Glantz and Hartel 1999). Although this is a frequent pattern for this chronic relapsing disease, we do not know if the changes in the brain are in fact gradual or precipitous in nature. The ‘switch’ seems to flip at different points for different individuals. That is, for some it may happen slowly or not at all, whereas for others it may happen rapidly. Researchers do know that once the switch is turned on and the individual becomes addicted, it is extremely difficult for most people to stop using drugs without treatment. Understanding this transition is a major area of investigation for researchers.

4. Long-Lasting Changes In The Brain

Studies in both humans and animals have demonstrated that chronic drug use changes the brain in fundamental ways that persist long after the individual has stopped taking drugs. This addicted brain is different from the nonaddicted brain, as manifested by changes in brain metabolic activity, receptor availability, gene expression, and responsiveness to environmental cues. These induced changes are responsible for the uncontrollable, compulsive drug-seeking and use—that are the essence of addiction. How long these brain changes last is just now being determined. Some of these long-lasting effects may also affect an individual’s emotional responses and his or her learning and memory capacity. One of the most recent examples can be seen with the drug methylenedioxymethamphetamine (MDMA) or ‘Ecstasy.’ MDMA is being used increasingly by teens and young adults who attend organized all night social gatherings or ‘raves.’ Chronic use of MDMA has recently been found to produce long-term damage to serotonin-containing neurons in the human brain. The neurotoxic effects of this drug have long been known in animals, but now we are seeing its damaging effects in humans as well. Given the important role that the neurotransmitter serotonin plays in regulating emotion, memory, sleep, pain, and higher order cognitive processes, it is easy to see how MDMA use can impair ones memory; and probably generate other behavioral consequences as well (McCann et al. 1998). MDMA can decrease an individual’s ability to remove this important neurotransmitter from the synapse, thereby amplifying its effects within the brain. This effect lasts at least three weeks after the individual has stopped using Ecstasy. Given serotonin’s critical role in many behaviors, one can speculate that this change in the serotonin system might be responsible for some of Ecstasy’s long-lasting behavioral effects.

5. Reversing Or Compensating For Brain Changes Through Treatment

Given that the brain fundamentally changes when an individual becomes addicted to drugs, preventing the initial use of drugs is of course the best treatment for preventing a lifetime of drug problems (National Institute on Drug Abuse 1997). If, however, the compulsion to use drugs takes over an individual’s life, treatments are available that can help an individual to stop using drugs and maintain a drug-free lifestyle. Many of today’s behavioral and pharmacological treatments for addiction can reverse or compensate for the brain changes that occur during prolonged drug use. Given that these changes in brain function do not occur in isolation, and are in fact interacting with environmental factors such as stress and situational triggers as well (O’Brien 1997) addiction is never simple to treat. It is often these external factors that cause an individual to relapse to drug use, even after successful treatment. Researches are working to determine what treatments work best for individuals who are likely to be affected by these environmental factors. Given that the ultimate goal of treatment is to return the individual back to a functioning member of society, it is critical that individuals can cope with these factors without relapsing to drug use.

Just as addiction affects all aspects of a person’s life, his or her treatment program must address the ‘whole person.’ It must address not only the individual’s drug use, but also provide him or her with the tools necessary for maintaining a drug-free lifestyle, while also helping with the achievement of productive functioning in the family, at work, and in society. Because addiction is so complex, and can impact so many aspects of the patient’s life, effective treatment programs typically must incorporate many components, each directed at a particular aspect of the illness and its consequences.

Fortunately, as with other illnesses, drug abuse professionals have at their disposal an array of useful tools to treat addicted individuals, though admittedly not enough. Treatments vary depending on the characteristics of the patient and the type of drug to which they are addicted. Treatment can include behavioral therapy, medications, or their combination. The best programs provide a combination of therapies and other services to meet the needs of the individual patient, which are shaped by such issues as age, race, culture, sexual orientation, gender, pregnancy, parenting, housing, and employment, as well as physical and sexual abuse (National Institute on Drug Abuse 1999).

Maintenance treatments such as methadone and LAAM (levo-alpha-acetyl-methadol) exist for treating heroin addiction; psychoactive medications such as antidepressants can be particularly useful when patients suffer from a co-occurring mental disorder; and notable behavioral interventions, such as cognitive behavioral therapies and contingency management, can be used effectively to treat both adults and adolescents. Another effective medication for treating some opiate patients, especially those with co-occurring alcohol dependence problems is Naltrexone. For persons addicted to nicotine, nicotine replacement products (such as patch, gum, or nasal spray) or an oral medication (such as bupropion) can be an effective component of treatment.

It bears repeating that the commonly held misperception that two of the most effective medications for treating heroin addiction—methadone and LAAM-—are simply substitutes for heroin is wrong. Instead of destabilizing the individual, as heroin does, methadone and LAAM stabilize the patient and facilitate a return to productive functioning (Ball and Ross 1991). It is also important to note that detoxification itself is not a form of drug treatment. At best, detoxification is a first step in beginning treatment, but by itself does little to affect long-term drug use.

Research studies have repeatedly demonstrated that addiction is eminently treatable and is comparable with the results found with other chronic disorders such as diabetes or asthma (O’Brien and McLellan 1996). Drug addiction treatment reduces drug use by up to 60 percent and has been shown to be effective in reducing the spread of HIV, diminishing the health and social costs that result from addiction, and decreasing criminal behavior (Hubbard et al. 1997).

6. Conclusion

Although the onset of addiction begins with the voluntary act of taking drugs, the continued repetition of voluntary drug taking begins to change into involuntary drug taking, ultimately to the point that a compulsive craving for the drug drives behavior. This compulsion results from a combination of factors, including in a large part, the dramatic changes in brain function produced by prolonged drug use. This phenomena explains why addiction is considered a brain disease—one with embedded behavioral and social aspects (O’Brien 1997, Leshner 1997). Once addicted it is almost impossible for most people to stop the spiraling of addiction on their own without treatment. Fortunately there are quite a number of effective treatments available to manage addiction.

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