Free Theories Of Addiction Essay Example

Abstract

Research in recent years is beginning to answer the question of what causes addiction to drugs and alcohol. Drug and alcohol addiction is a problem the affects millions of people. The costs of addiction affect the addict, the family, society, employers and government agencies. Not all people who drink or use illegal drugs become an addict. Millions of people have experimented with drugs or drink socially and never develop into an addict. There are two theories that have emerged in recent years that are beginning to explain why some people become addicted. This paper will examine and compare two of the more popular theories of addiction: incentive sensitization and instrumental learning and classical conditioning.

Introduction

Many years ago, alcoholics and drug addicts were viewed as Skid Row bums who could not stop themselves from using and drinking. They were considered hopeless in the eyes of mainstream society. Alcoholism has been around for several millennia, ever since man first learned how to ferment grapes and grains. Drugs have also been employed in many cultures, often for spiritual reasons. The 20th century saw a tremendous surge in illegal drug use. Recreational use of marijuana, opium, hashish, heroin, cocaine, crack and methamphetamines have all enjoyed periods of popularity. The vast majority of the population has tried an illegal drug, 60% of people have tried an illegal drug at some point in their life. If alcohol is added to the equation the percentage of those that have tried either rises to 90%. The percentage of the population that actually become addicted to a substance numbers approximately 20%. This statistic has been researched by thousands who wish to understand why a small percentage of the population becomes addicted to a substance when so many more have tried the substance, used the substance for a while and were able to walk away with no negative consequences. People who drink also exhibit similar numbers. Drinking is socially acceptable and perfectly legal. The overwhelming majority of people can have a drink or two and walk away from it, others obsess about drinking and cannot stop despite major upheaval in their lives due to drinking (Robinson & Berridge 2003, p. 26).
Drug addiction is defined by chronic use, thoughts and search for drugs. This behavior continues unabated despite serious consequences in a person’s life: loss of relationships; loss of family; loss of a job. Addicts seek out drugs because of the euphoric state of mind the drugs induce. This feeling is so pleasant to the addict, they will go to any lengths to repeat it. Chronic use of the substance results in craving, increasing tolerance for the drug, physical dependence and sensitization. When the drug is not available for consumption, the addict will experience physical withdrawal and will obsess about the drug until he can get more. The addict will engage in extreme behaviors that they normally would not participate in in order to obtain and use their drug: stealing; lying; calling in sick to work. Addiction affects both the physical and the mental state of the addict (Cami & Farre 2003, p. 975-976).

Sensitization

According to Robinson and Berridge (2008), sensitization is “hypersensitivity to the
incentive motivational effects of drugs and drug-associated stimuli”. Incentive sensitization is the process of wanting the drug and thinking constantly about obtaining and using it. Robinson & Berridge (2008) explain that when incentive sensitization is coupled with poor executive control addiction occurs. Incentive sensitization occurs after repeated use of a drug. The drug causes biological changes in the brain and pathways of neurons in the brain. The brain develops a link between a stimuli (the drug) and the reward (the high). This is called incentive salience. Addicts may refer to this state as craving or obsession. Incentive salience causes repetition of the behavior to use drugs. The more frequent the use, the stronger the incentive salience becomes. Even after stopping the use of the drug, the incentive salience continues to exist and lasts for years, the recovering addict often has the urge to use again. This state of mind can result in a relapse. Neural sensitization is the biological component of sensitization, it results from changes occurring in the synapses of the brain. Sensitization does not occur alone in the drug addict’s behavior. Research has also proven that executive brain function is altered by drug use. Executive function occurs in the frontal lobe of the brain and is responsible for organizational skills, remembering details and curbing inappropriate behavior and language. This impairment from the use of drugs promotes poor decision making in using more drugs. It becomes a vicious cycle (Robinson & Berridge 2008, p. 3138).
Incentive sensitization plays a major role in the inability to quit using drugs. Sensitization and increasing tolerance for the drug occur concurrently. This dichotomy results in aversive psychological and physical if the addicts does not take his drug. The negative effects on the mind and body make it nearly impossible for the addict to quit. The brain has become wired to seek out the drug and behavior to obtain and use follows suit. The stimulus response learning that occurs with the use of drugs causes decreased or malfunctioning of the prefrontal lobe. This leads to uncontrollable behaviors and poor decision making. This leads to maladaptive learning. This cycle constitutes the addiction to a drug that differentiates the addict from the recreational user. Research in neurobiology has shown that drug use causes changes at the cellular level in the brain that leads to changes in the DA and neurotransmitters in the brain. Behavioral and physiological factors are responsible for addiction. These findings have supported the theory of sensitization (Feltenstien & See 2008, 262-263).
Everitt and Robbins (2005) also present research on addictions that links addiction to both behavioral and physiological origins. Drug use begins voluntarily. People partake of drugs because they create a pleasurable sensation. Some people however, cannot stop using drugs. The return over and over again to use the drug to gain that heady feeling. The use of the drug progresses from recreational to habitual to compulsive. The use of the drug and the development of an addiction is a result of the sensitization of the drug. They state that addiction is “a transition at the neural level from prefrontal cortical to striatal control over drug seeking and drug taking behavior as well as a progression from ventral to more dorsal domains of the striatum, involving its dopaminergic innervation”(Everitt & Robbins 2005, p. 1481).
Incentive sensitization can be summarized in four concepts. The first is that drugs have the ability to cause long term changes in the brain. The areas of the brain that are affected are responsible for motivation and reward. The neuroadaptations of the brain become hyper-sensitized to drugs and the stimuli associated with drugs. Finally, the part of the brain that is sensitized is not the part of the brain that receives the euphoric effects of the drug, instead it is responsible for the reward and wanting of the drug. The neural substrate that is affected is the dopamine system. When these processes occur, the user has become the addict. The addict is not aware of the behavioral and physiological changes that are occurring. The increased drug use an addict experiences because of increased tolerance exacerbates this process. The addict may be miserable and recognizes the destruction drugs have in his life he is unable to stop and he does not understand why (Robinson & Berridge 2001, 103-104.)
The effects of sensitization has been researched extensively with rats. Rats that are given psychostimulants signs of enhanced locomotor responses when exposed to the drug at a later time. The reactivity of dopamine neurons is heightened. These effects last for up to three months after exposure to the drug. These findings have been discovered in human subjects as well. PET scans and MRI images of the brains of cocaine addicts. This heightened state exists with positive moods and craving for the drug. When cocaine addicts were allowed to see and use a razor, mirror, straw and some cocaine, dopamine response was high. When cocaine was administered in pill form and the former stimuli were not present, dopamine response was much lower. This experiment supports the theory of incentive sensitization (Vezina & Leyton 2009, 162-165).
In a study conducted by Everitt and Wolf (2002), the relationship between stimulant drugs such as cocaine, the nucleus accumbens and the dorsal striatum leads to a Pavlovian response and a learning process. This cycle is what is believed to lead to drug addiction. Again the stimuli that is associated with cocaine addiction, mirrors, straws, razors, produces a strong desire for cocaine. The exposure to these stimuli results in a strong reaction from the dorsal striatum, nucleus accumbens, and the prefrontal cortex. The implications of this study and studies like it, are the physiological aspects of cocaine and stimulant addictions. Is it possible that pharmacology can provide a cure to help with these addictions by altering these areas of the brain so that they do not respond to stimuli associated with drug and help increase the chance for recovery from addiction (Everitt & Wolf 2002, 3312-3313).
The majority of research on the theory of incentive sensitization and the effects on the physiology of the brain has been performed with addicts who use stimulants such as cocaine, methamphetamines and other stimulants. Is it possible to develop a pill that could control the areas of the brain that are stimulated by the sensitization of stimuli associated with the drug use? Does the theory apply to other types of addiction such as opioids and alcohol?

Instrumental Learning

The theory that drug addiction is a learned behavior has been popular for decades. This theory postulates that the high that is associated with the use of drugs is a positive reinforcement. This type of consequence is desired and will be sought after again. The more often this occurs, the stronger the conditioning is becoming. After time this process is not though of consciously and thoughtfully. It becomes habit. A conditioned reinforcement (secondary reinforcement) often occurs concurrently. This secondary reinforcement can also trigger a learned behavior if it is paired with the primary reinforcement often enough. If the reinforcement is not available for a period of time, the minute it is reintroduced it will produce the desired behavior. Partial reinforcement can occur if the reward is not attained every time the behavior is performed. Often behaviors are paired with antecedents that encourage the appearance of the behavior. Extinction is the process of removing the positive reinforcement to force the disappearance of a behavior.
These principles have been applied to addiction both to explain the existence of the addiction and in helping to promote recovery from addiction (Staddon & Cerutti 2006, 115-117).
According to Kelley and Berridge (2002), “It has long been recognized that reward processing depends on mesocorticolimbic DA systems, comprising DA neurons in the ventral tegmental area (VTA) and their projections to nucleus accumbens (NAc), amygdala, prefrontal cortex (PFC), and other forebrain regions” (p. 3306). The act of being conditioned to use drugs because they produce a desired mental state originates in the brain and the production of dopamine. This information does not supplant the theory of instrumental learning but instead strengthens it. The reward of the high coupled with the changes in the brain make taking a drug highly desirable.
The behaviors that are learned through the demonstration of a behavior (taking the drug) and the reward (the high) become stronger every time it occurs. Eventually the behavior has been deeply ingrained in a person and it seems close to impossible to cease the behavior. Periods when the drug is not available only serve to strengthen the desire to engage in drug taking behavior. The desire to obtain the reward is so deep that an addict will go to almost any length the achieve it (Kelley and Berridge 2002, 118).
Winger et al (2005) take a strict behavioral view of addiction. They state in their study that there is merit to the neuroscience associated with addiction but it does not explain drug use in general. For example, many young people experiment or use drugs. The behavior of use is reinforced with the high. However, behaviorally speaking outside reinforcers soon come into play such as a new job or marriage and family that are more rewarding than the drug use. The researchers also make an example of cigarettes smoking. Cigarettes are highly addictive and very difficult to quit. Research has shown that cigarettes have the same effect on the physiology of the brain as drugs. However, every year millions quit smoking successfully by changing their behaviors. Neuroscience is making tremendous progress in the area of addiction, but the basics of addiction: obsessing about the drug, obtaining the drug, the rituals associated with using the drug and the high that the results in are behaviorally based.
The behavioral approach also offers better success with recovery from drug addiction. Many programs of recovery replace addictive behaviors with new, healthy behaviors. 12 step programs such as Alcoholics Anonymous employ the method of introducing and reinforcing new behaviors

Which have proven successful in keeping alcoholics sober.

Conclusion
Incentive sensitization theory offers interesting ideas on the subject of addiction. This model suggests that behaviors associated with drug use and addiction produce specific chemical reactions in the brain and physiological responses to the introduction of the drug into the body. The theory also suggests that stimulus associated with drug use can produce the same effects. The last ten years has seen a tremendous amount of research on the subject as scientists explore the relationship between drugs and the brain. However, the majority of the research has been completed using cocaine and other stimulants.
Instrumental Learning is a theory that is supported by behaviorists. They view addiction as a behavior that is sought after and repeated because of the rewards associated with use. The more often the behavior and the positive reinforcement occur, the stronger the addiction becomes. Behaviorists do concede that the behaviors of ingesting drugs does cause the same physiological changes in the brain that sensitization does. Behavioral theory can be applied to all types of addiction. Behavioral techniques are also very successful in treating addiction.
Both theories have their strong points that can be applied to addiction and answer so many questions. Unfortunately neither school of thought has all of the answers. Questions such as why rates of addiction are higher among certain racial and ethnic group and why men have higher rates of addiction are not answered by either school of thought. Why addicts choose the drugs they do and remain loyal to them is also unanswered. Addiction is still a prevalent issue facing not only the individual addict, but his family and society as well. Continued research needs to be done.

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