Running head: BRAIN CHEMISTRY IN ADDICTION   1
BrainChemistry in Addiction
TheWorld Health Organization (WHO) defines addiction as a chronic andperiodic state of intoxication arising from perpetual consumption ofalcohol and drugs. However, modern definitions associate addiction toloss of control over one’s behavior. Addiction is a compulsivebehavior that occurs regardless of individuals volitional attempts tomoderate it. The brain loses its control over the use or associatingwith addictive substances even when adverse effects are experienced.As such, addiction becomes a chronic disease as the brain loses itsregulatory power and becomes ensnared to the influence of drugs(Koob, 2004). Addiction also leads to the erosion of brain capacityfor self-control and ability to make a good decision (Hayman G.(2009).
Addictionis a developmental disease that starts casually and develops as ahabit as the subject use and associate with the object of addiction.There is no single attribute that can ascertain whether a personwould become addicted or not from the use of a particular substance.However, there are risk factors that predispose individuals toaddiction. These risk factors include the social environment,individual’s biological genes and development. For instance,individual’s genetics, ethnicity, gender or mental disorders maypredispose the person to drug addiction. The environment of anindividual could also influence one to addiction due to such aspectsas peer pressure, stress, family and friends (Begley & Schwartz,2002). Similarly, a person developmental stage in life alsoinfluences their addiction vulnerability for example, adolescentsface serious addiction problem due to biological (great hormonalchanges) and social environment (peer pressure).
Recentstatistics indicates that, nearly 23 million Americans are underalcohol and other drug addiction one individual out of ten is likelyto be an addict. In this category, more than two-thirds are addictedto alcohol (Hayman, 2009). The major drugs abused are the opioids(narcotics), marijuana and cocaine. The cause of addiction is nowbetter understood with the neuroimaging technologies, neuroscienceresearchers indicate that pleasurable activities such as sex,gambling, and shopping co-opt the brain. Back in the 1930s whenresearch on addiction began, people believed that addiction was dueto lack of willpower on victims’ ability to overcome addiction(Hyman, 1994). However, recent scientific studies indicate thataddiction is a chronic disease that hijacks the brain instigatingchemical changes that alter the brain capacity to regulate compulsivebehaviors(Tannenbaum, 2008).
Thebrain is a sensitive organ and registers all pleasures from objectsand activities like money rewards, psychoactive drugs or a sumptuousmeal in a similar way. These pleasure influence the brain inreleasing dopamine and serotonin chemicals in the nucleusaccumbens-the cells found in the cerebral cortex (Hayman, 2009). Thedopamines the serotonin are greatly affected by substance abuse. Inparticular, the brain pathway center is greatly influenced by drugsand alcohol. The neurotransmitters (serotonin and dopamine) havechemical hormones associated with pleasurable feelings and overconsumption of drugs and alcohol leads to overstimulation of thehormones (Tannenbaum,2008).As such, when an individual uses drug a powerful dose of dopamine isreleased in the brain leading to an immediate pleasurable feeling.This is called the pleasure effect, and it has been found that, theintensity and the speed with which dopamine are released increase therate of addiction (Kuhar,2012).
However,scientists believe that, the experience of pleasurable feeling doesnot always lead to addiction, rather the dopamine releasedfacilitates in learning and memory development in relation to theobject of ‘pleasure.’ The underlying theory of this argument isthat, dopamine interacts with glutamate (another neurotransmitter) inleading to pleasure –related learning (Koob, 2004).
Inparticular, drug addiction alters the brain functioning by imitatingthe natural neurotransmitters (brain messengers). There existssimilarities in chemical structure between the drugs and theneurotransmitters and as such, the drugs ‘fool’ the brainreceptors in activating the nerve cells (Hayman, 2009). In the sameline, drugs cause overstimulation of the nerve system and flood thereward circuit with dopamine thereby affecting the brain capacity toregulate emotions, movements, pleasurable feelings and motivation(Begley & Schwartz, 2002). Consequently, this leads to acuteaddiction and reduced dopamine production. Individuals continue touse drugs or participate in the act of ‘pleasure’ even when realpleasure is not derived (Koob, 2004). The brain in its normalcondition and with the help of serotonin and dopamine can regulateemotions and the motor function of the body (Kuhar,2012).
Thebrain coordinates the functions of the human body the dopamineneurotransmitters control the body movements and balance (Hayman,2009). Serotonin neurotransmitter, on the other hand, controls thebody movement by managing other neurotransmitters (Begley &Schwartz, 2002). The brain chemistry addiction is thus an essentialtopic that needs in-depth exploration to understand the salientchemical processes that take place in the brain and how addictionaffects the overall functioning of the brain and individualsbehavior.
Ideally,most people are clueless on why people get ensnared to drugs. Manylack the conceptual basis on how drug addiction comes about and seedrug addicts as individuals lacking will power and moral principlesto stop drug abuse. In reality, drug addiction is a complex probleminterconnected with biological, behavioral, psychological and socialfactors. While drug addiction starts as a simple act andprogressively turns into a habitual and obsessive behavior, quittingdrug addiction is quite a challenge and requires great effort and astrong-willed personality. The underlying challenge towards quittingdrug abuse is based on the fact that drug abuse lead to adversechemical changes in the brain that makes addicts totally dependent ondrug use and stopping becomes impossible. Anyone can be hooked todrug abuse, but quitting drug abuse is a challenge as brain neuronsbecomes tied to drug addiction (Begley & Schwartz, 2002).
Ina broader sense, drugs alter the brain chemical balance the braindopamine becomes dependent on drugs for its functioning-the impulsiveeffect (Tannenbaum,2008).The brain neurotransmitter dopamine is responsible for pleasurefeeling and is released in the nucleus accumbens. This serves as apositive signal that the action resulted in a ‘reward.’ As such,based on the recording of ‘positive’ experiences and with pairedeffect of memory and learning from serotonin an individual is likelyto repeat the action.
Ideally,‘rewards’ comes after a significant ‘delay’ of action leadingto pleasurable feeling (Kuhar,2012).However, drugs accelerate or act as a short-cut to pleasurablefeelings by prompting massive production of dopamine and serotonin inthe accumbens (Begley & Schwartz, 2002). Over usage of drugsfails to provide ‘pleasurable’ feeling after drug intake due tochemical changes and adaptation processes in the brain (Tannenbaum,2008).Successive drug usage inhibits the production of dopamine leading toreduced ‘reward feeling’ and continued drugs use becomes thesource of new ‘pleasure.’ The implication is that the accumbenshave been damaged or that some drugs have blocked the release ofdopamine rendering the reward system less effective (Koob, 2004). Inthis context, the brain has lost its control, and addicts need higherdoses of the drugs to keep the brain ‘stable’ (Begley &Schwartz, 2002).
Theoreticalframework of addiction
TheDisease Concept or the theory of drug addiction
Thereare various theoretical perspectives on brain chemistry andaddiction. The proponents’ of drug addiction and the real diseaseconcept argue that, addiction is not a disease in particular, justlike the behaviorist theorist, they regard addiction as a personal‘choice’ and not necessary a disease(Begley, 2004).Although, addiction has been identified as a brain disease thatresults from changed brain functions, the disease proponents’theorist refutes the claimthat addiction is a disease (Hayman, 2009).Instead, they claim that the abnormal changes in the brain due todrug use are not abnormal as such and people are capable of changingthrough behavioral modification (Hyman,1994).In addition, the disease concept theorists observe that there isexists no proven that addiction is a compulsive or involuntarybehavior as such.
Furthermore,the disease theory proponents argue that progressive brain scansconducted on ‘heavy addicts’ do not indicate malfunctioned brainon drug addicts (Begley,2004).Furthermore, the disease concept theorist argue that the brain is ina state changes as individuals ‘think’ or engage in a particularactivities regularly and as such different regions and theneuron-communications pathways grow or become less active dependingon the intensity of their usage (Tannenbaum,2008).This process continues throughout one’s life. Therefore, there isnothing abnormal about it. For instance, a cab driver who constantlynavigates a busy street develops physical changes in the brain, inthe same way, a drug addict brain changes (Begley& Schwartz, 2002).In short, the more an individual engages in a particular activity,the more changes in the brain and one cannot be considered to havebrain disease as a result of drug addiction(Heyman, 2009).
Inaddition, the disease concept theorist refutes the claim thataddiction is a brain disease because it results from routine exerciseof particular activities (Kuhar,2012).Individuals change their behaviors despite the ‘diseased brain’and they do it voluntarily and without any medication or surgery(Heyman, 2009). Another point is that, substance use is a choice andnot a compulsive urge as such there is no evidence that addicts areincapable of resisting the compulsive urge (Begley, 2004). Even ifobsession was the driving force and there is an influence ofaddiction from environmental cues, this does not impede individualsfrom resisting the urge in short individuals are capable of makingvoluntary withdrawal based on choice (Begley, 2004).
Thedisease concept theorists base their argument on the fact thataddicts can withdraw from drug addiction after a counseling therapyand psychological orientation (Begley & Schwartz, 2002). Insummary, addiction is not a disease because no proof exists ofpsychological malfunction individuals volitionally change theirbehaviors, and that drug use are not compulsive as such but a choice(Heyman, 2009).
Psychologyof addictive behavior
Thebehavioral psychologist view addiction as an individuals’ choice ofactions. In this light, addiction is a product of repeated pattern ofbehaviors that eventually leads to loss of control over suchbehavior. Addiction is a biological, social, psychological andbehavioral problem because there is persistence in theself-destructive behavior, inability to stop, desire to stop thehabit, and certain behaviors are used as therapy strategies againstaddiction. In addition, addictions are behavioral becauseoccupational, social and creative activities are abandoned in pursuitof the addicted behavior and lot of time is spent pursuingrehabilitation remedies and recovery.
Biologicaland medical perspective on addiction
Inregard to model of addiction, biologically, addiction results fromsomething physical brain genes, brain structure or the brainchemicals. Chemical substance leads to physiological changes in thebrain by altering the brain chemistry and neurotransmittercommunications. The capacity to alter the nerve pathways by thechemical substances result in psychological conditions (Tannenbaum,2008).It has been researched that, chemical substances result in the damageor impairment of the limbic system that is responsible for regulatingindividuals’ behavior (Kuhar,2012).
Successiveusage of these chemical substances renders the brain incapacitated,and the drug user needs to ‘replenish’ the chemical substances inthe brain to regain ‘normalcy’ (Kuhar,2012).In this case, there is an overlap of various perspectives leading tothis condition there is the biological ‘urge’ to replenish thechemical substance in the body, the behavioral urge to engage in thepleasurable act which may have been influenced by social environment(i.e. peer pressure, stress). Individual’s genetics paired with ashared environment possibly from addictive parents have beendiscovered to influence drug addiction (Tannenbaum,2008).
Behavioristssee addiction as learned as espoused by Ivan Pavlov perspective onclassical and operant conditioning. According to Pavlov the socialenvironment in which an individual lives facilitates in the learningof particular behaviors or habits. In his experiment, he discoveredthat ‘rewards’ stimulates and reinforced compliant to particularresponses while punishment reduces the recidivism of a particularbehavior. In respect to Pavlov theorem, addicts are motivated by thepleasurable feelings in their body to repeat a particular behaviordeemed pleasurable (Begley & Schwartz, 2002).
Behaviorsare acquired through association (classical conditioning) of theaddiction substance and excitement. In a similar manner, individualsinitiate particular behaviors after observing others as they imbibethe chemical substances and maintain the behavior through operantcondition. As such, behaviorist bases their arguments of addiction asa result of learning and conditioning. The overall effects are thatthere is an overlapping of salient factors leading to addiction. Thebehavioral concept of classical conditioning as the influence inlearning fails to explain succinctly why addicts continue with theirbehaviors even after adverse effects. However, the classicalconditioning perspective explains why a relapse occurs afterabstinence in the event of a slip.
Cognitiveperspective on addiction
Accordingto the cognitive perspective, addiction is attributed to faultythinking, poor decision making, relapse prevention and perceptualbiases. Addicts have irrational beliefs and underestimate oroverestimate the repercussion of their indulgence. For instance,gamblers overestimate their winning while drug addicts false fullyindulge in drug abuse as a form of self-medication and lack ofconfidence to remedy their condition (Begley & Schwartz, 2002).On the other hand social theorists consider the society as asocialization agent that directly or indirectly affect individuals’cognitive and behavioral aspects culminating to addiction.
Theoryof planned behavior (TPB) on addiction
Accordingto this theory individual’s attempt control, certain behaviorsincrease the urge to engage in such behaviors and addicts whoperceive that they have more control over their behavior, the harderand longer their trials. The theory is part of rational action theorythat associates behavior to individual beliefs, intentions andattitudes. In this case, individuals’ attitude towards a particularbehavior shapes their intentions to participate in such behaviorsafter a reasoned evaluation. In a broader sense, individuals evaluatethe suitability of particular behaviors or actions before engaging inthem. As such, the theory is mostly used in behavioral therapy casesinvolving addiction to help addicts recover from the negativebehaviors leading to drug abuse.
Inthe human body, the brain is a complex organ that plays an essentialrole in producing electrical signals that combine with chemicalreactions to enhance communication with other parts of the bodythrough a network of nerve cells in the body. In this way, the braininterprets senses initiates motor functions coordinate and controlphysical, physiological, biological and psychological aspects of thebody as well as controlling behavior. In order to achieve thesefunctions, the brain has several parts that work in unison althougheach part has its specific attributes.
Thebrain is composed of the gray matter (40%) and the white matter(60%), all constituting the brain cells. The brain is partitioned inthree main functional areas which are the cerebrum, cerebellum andthe brain stem (medulla). The hindbrain (medulla) has the cerebellum(1) that coordinates motor functions of the body. The largest part ofthe human brain is the forebrain that is highly developed and largelymade up of the Cerebellum (2). The whole brain is connected to thecentral nervous system (CNS) found in the spinal cord that carriesbrain message (Koob, 2004). The brain cells (the neurons) areresponsible for processing and transmitting messages across thebrain all signals arising from sensation, memories, thoughts andfeelings pass through the neurons.
Themost significant feature of the human brain is the Cerebral cortexand occupies the largest part of the human brain with billions ofneurons connected to each other through synapses. Most informationprocessing takes place in the cerebral cortex (coating surface of thecerebellum) and is often referred to as the ‘gray matter’(Douglas& Martin, 2004).The cortex is sub-dived into three distinct functional regions theprimary sensory area, the primary cortex and the association areaswhich process complex aspects (Tannenbaum,2008).It is the cerebral cortex that has an extensive network of nervecells responsible for the production of the chemicalneurotransmitters such as dopamine and serotonin responsible forregulating pleasure (Kuhar,2012).The neurons communicate with each other and transmit messages acrossthe brain network through a train of signals pulses and fibers (axon)(Douglas & Martin, 2004).
Physiologically,the brain is tasked with a centralized coordination and control ofthe other parts of the body by enhancing the generation of muscleactivity and secretion of brain chemicals (hormones). The nature ofthe brain is to enhance centralized coordination of body activitiesfor rapid response to changes in the environment (Begley &Schwartz, 2002). However, reflex actions are coordinated by thecentral nervous system but complicated behaviors are mediated throughthe integrated and centralized capacity of the brain (Kuhar,2012).Philosophically, the brain is quintessential to mind that allowsindividuals have conscious understanding of various aspects in theenvironment. Neuroscientists and others see the brain as analogous tobiological central processing unit (CPU) in computers.
Thefundamental function of the brain is the transmission of electricalpulses from one cell to another and response to impulses receivedfrom other cells. The brain cells (neurons) have naturalneurotransmitter chemicals and receptors that the communication inthe brain to take place through the synapse (Douglas& Martin, 2004).In this way, the brain allows interaction processes between thereceptors and the neurotransmitters through the synapse (Hyman,1994). These neurotransmitters are the glutamate, the serotonin andthe dopamine chemicals among others. The neurotransmitters have acommunication pathway that allows brain cell communication andeffective transmission of information. In addition, there is apleasure or the reward circuit or the mesolimbic dopamine system isfound in the cerebral cortex (Koob, 2004).
Druguse alters this mesolimbic dopamine system and other parts of thebrain functions. Some highly sedative drugs like heroin imitate thework of natural chemical transmitters in the brain while other drugsblock receptors in the brain and neuronal message transportation.Other drugs like cocaine block the dopamine transporters leading tore-pumping of dopamine back to the neurons thereby intensifying andextending the stimulation pleasure ‘the high feeling.’ Extendeduse of these drugs switches the communication pathway of the braincircuits (Douglas& Martin, 2004).
CommunicationNetworks in the Brain
Thebrain has a network, of billion nerve cells that are responsible forcommunication. These cells operate in a network, and the activity ofone cell influences the action of the other cells.
Communicationin the brain is largely through electrical activation of the neuronsthe chemical transmission of signals between neurons through thesynapses. Neurons have special properties and are unique in theirroles they play in the brain. A neuron has three significantfeatures the nucleus, the dendrite and an axon. Individual neuronsare separated from each other and do not share chemical or electricalimpulses directly. The only connection occurs through electricalsynapse in which ion-conducting pores enhance the flow of ion fromone cell to another thereby creating a connection bond (Hyman, 1994).The neuron surface has excitable cells with charged ion-channels thatallow other charged particles to pass through it. The neuronstructure allows information to be received by dendrites anddispersed through the cell body to the next neuron (Koob, 2004).
However,as the signal passes through the neuron body, a chemical reactiontakes place in the synapse structure, and neurotransmitter chemicalsare released. In the synapse, two cells the postsynapticneurons and presynapticcomeinto contact to allow for chemical transmission to take place. Inthis case the presynaptic cell releases neurotransmitter chemicalsthat are in turn received by the postsynaptic neurons called theneurotransmitter receptors. Besides the neurotransmitters in theneutrons, there are neurotrophinsthat support the growth of the neurons (Koob, 2004). Furthermore,there are steroid hormones molecules that participate in theintercellular communication.
Thepharmacology of neurotransmitter receptors
Duringthe neutron to neutron communication, the neurotransmitters act asnatural agonists that facilitate the binding between two neutrons.Research indicates that, in the pharmacology of the communicationnetwork of the brain, foreign chemicals such as drugs act as anantagonist and inhibits the receptor activation during the neuron toneuron communication (Tannenbaum,2008). In some instances, the antagonists inhibit the binding ofneurotransmitters or might change the formation of receptors makingthe activation difficult. The resulting effect is that, theantagonist competes with the natural neurotransmitters for binding inthe neurotransmitters receptors.
Theagonist and antagonists are used in the development of pharmaceuticaldrugs that cure neurological and psychological disorders. Forinstance, the Haldol is an antagonist drug used in the treatment ofschizophrenia while Ambien an agonist drug is used in the treatmentof sleep disorder. Most drugs legal and illegal target the neuronaltransmission of signals in the brain by blocking or competing forbinding with natural receptors (Tannenbaum,2008).The resultant effect is that a lethal neurological disorder arises asneurotransmitters dies, or their roles are inhibited by the foreignchemicals that imitate the natural chemicals. The most affectedneurotransmitters are the GABA, Glutamate, Dopamine and the Serotoninneurons.
Drugabuse alters or ‘replaces’ the brain chemical with foreignchemicals (drug) (Begley & Schwartz, 2002). Besides theneurotransmitters, the steroid hormones and neurotrophin affects theneurons functions through altering the intracellular impulse pathwaysand gene expression. Studies indicate that, excessive alcohol alterthe synaptic transmission in the brain as well as the brainconcentration. In particular, alcohol adversely affects theneurotransmitters, steroid and neurotrophin hormones leading to acuteintoxication and tolerance adaptation and eventual dependence onalcohol.
Dopamineand Serotonin Pathways
Thereare billions of nerve cells and neurons that enhance communication inthe brain through chemical messages (transmitters). It is within theneurons that the transmitters are made and when stimulation occurs anelectric pulse is passed. The neurotransmitters are brain chemicalsthat transmit signals from one target to another. Among the majorneurotransmitters secreted by the neurons in the brain is thedopamine and are transported through the synapse. Dopamines are morewidespread than other monoamines and reside in the midbrain gray,hypothalamus and the retina areas among others. The dopamines areresponsible for pleasure, motor function, motivation and stimulation(Begley& Schwartz, 2002).
Thedopamine pathway refers to the neural pathway involved in thetransmission of dopamine from one part to another. The dopaminepathways include the mesolimbic, the mesocortical, the nigrostriataland the tuberoinfundibular pathway. The mesolimbic system facilitatesthe transmission of dopamine in the Limbic system (Koob, 2004).
Rewardsincrease the dopamine level in the brain as well as drugs thatinfluence the neuronal activity in the brain. For this reason, thepathway is associated with neurobiological aspects such asdepression, addiction and schizophrenia. These neurobiologicalconditions occur in similar structural changes as during dopaminetransmission. The mesocortical pathway is part of the dopaminesystem and closely associated to the mesolimbic pathway is involvedin the control of the cognitive process, emotions and motivationresponses. The nigrostriatalpathway assists in the transmission of dopamine along the dopaminepathway from the substantial nigra to the neostriatal. Thetuberoinfundibularpathway, on the other hand, facilitates in the transmission ofdopamine to the pituitary glands from the hypothalamus. In addition,the tuberoinfundibular pathway is involved in hormonal regulation,helps to nurture behaviors, useful during pregnancy and manages thesensory processes(Begley& Schwartz, 2002).
Theserotonin pathway is associated with the regulation of mood and anydisorder in the pathway arising from depression, addiction to drugsand anxiety leads to the pathway dysfunction. The serotonins areresponsible for regulating various processes in the brain. Theseinclude emotions, memory, sleep, mood, appetite, perceptions andlearning. In the structure of the brain, the serotonin found in thehippocampus regulate memory, serotonin in the limbic system regulatemood while serotonin in the forebrain (front cortex) regulatecognition, perception and memory (Douglas& Martin, 2004).
Inthe event of drug abuse the dopamine, serotonin and the glutamateneurotransmitters are adversely affected. In particular, drugs alterthe chemical reactions and communications of these neurotransmittersthereby affecting their functioning. Similarly, drug abuse alters thebrain reward systems by damaging the nucleus accumbens whichinfluence the hippocampus to slow down memories of rapidsatisfaction. As a result, the hippocampus in combination with theamygdala result in conditioned response to particular stimuli thisis the root of conditioned learning that in turn leads to obsessivebehaviors.
Theglutamate and the GABA
Theseare the most plentiful neurotransmitters in the brain and are heavilyused in the synapses. The GABA neurotransmitters are inhibitory whilethe glutamates are excitatory, and this makes them to and worktogether in controlling many processes especially the brainexcitement. Most drug abuse alters the balance of the GABA and theglutamate neurotransmitters resulting in a stimulating ortranquilizing effect in the brain. Drugs abuse may either increase ordecrease the GABA and the glutamate functions in the brain. Forinstance, alcohol decreases the glutamate activity in the brain whileit increases GABA activity in the brain.
Whathappens to the brain one start taking drugs?
Drugcontains chemical substances that behave, in the same way, as thenatural chemicals in the brain. The brain has a reward circuit andaddictive substances alter the normal functioning of the circuitleading to drug dependence. Drug abuse changes the braincommunication system thereby disrupting the brains cells capacity tosend, receive and process information in an ordinal way. The drugchemicals achieve this by imitating the brain chemicals, overstimulating the reward system, flooding the brain with surplusneurotransmitters and blocking the receptors of neurons.
Thenature of the brain is that, it registers, in the same way, allpleasures whether monetary, food or emotional attachment. Thesepleasures results in distinct signatures in the brain and leads torelease of dopamine neurotransmitters (Douglas& Martin, 2004).When addictive drugs such as alcohol, cocaine and hero are used, thedrug chemicals travel through the blood stream to the reward pleasurecenter. These drugs have chemical substances that tap into the braincommunication system and alter the way the brain cells (neurons)send, receive and process information in the brain (Berke, 2000).
Drugchemicals imitate the natural neurotransmitters in the brain, and theprocess of activating the neurons is different from that of naturaltransmitters and this results in abnormal information beentransmitted through the neurons (Koob, 2004). The chemical structuresof abused drugs such as heroin and marijuana is similar to thenatural transmitters in the brains. As such, this similarity inchemical structure ‘fools’ the neuron receptors in the brain andallow drug chemicals to get attached to the neutrons (Hyman, 1994).In this way, just like the natural brain chemicals, the drugchemicals stimulate the reward system leading to secretion ofdopamine transmitters (Tannenbaum,2008).
However,unlike the natural neurotransmitters, abused drugs over-stimulate theneurons leading to a powerful surges and overproduction of dopaminechemicals in the accumbens which inhibit the normal recycling ofthese chemicals by the brain (Berke, 2000). The resulting effect ismore amplification of the message consequently disrupting thecommunication networks in the brain. As an individual continues touse drugs, the brain in its normal capacity adjusts excess or lowerdopamine levels in the brain (Tannenbaum,2008).For instance, in the case of excess dopamine the brain reducesdopamine receptors and the overall level of dopamine in the brain.This regulation of dopamine level in the brain after drug use leadsto reduced pleasurable feeling by the drug addict and hence an ‘urge’to take more drugs arises in order to achieve the ‘high feelingeffect.’ In this context, the abuse of the drug to get the ‘high’feeling leads to the disruption on the normal functioning of thereward system in the brain (Tannenbaum,2008).
Abuseddrugs act as a shortcut to natural reward system. The rapid sensationfeeling is recorded and kept in memory by the hippocampus and theamygdala that creates a conditioned response to such rapid sensationsatisfaction (Douglas& Martin, 2004).Recent studies indicate that, it is not the surge and rapid sensationfeeling that leads to addiction, but learning and memory processenhanced by the dopamine. These are key factors that lead drug users’transits from ‘enjoying’ drug abuse to addiction level. Thetheory of addiction is that, the pleasurable effect of dopamineinfluences the glutamates in reward learning process in the brain(Berke, 2000).
Ideally,normal life-sustaining activities such as meal taking results in thisreward-related learning. The reward system which constitutes thedopamine, serotonin, the GABA and the glutamate pathways plays coreroles in pleasure, motivation and memory control. Repeated exposureto drugs ‘turns on’ the prefrontal cortex nerve cells (part ofthe brain that plan and execute tasks) by sending signals across thebrain that motivate the addict to seek drugs for pleasure (Douglas& Martin, 2004).
Atthis stage, due to the changed reward system, the pleasure (highfeeling) achieved from drugs subsidizes considerably but the memoryof the desired ‘pleasure’ persists uncontrollably. Similarly, atthis stage the normal operation of the reward systems do not have anyeffect in eliciting the pleasurable feeling even from naturalself-sustaining activities like food or sex (Berke, 2000). There isno pleasurable feeling from the brain natural transmitters, and thescientific argument is that, the dopamine and other neurotransmittershave been rendered ineffective (their production inhibited or thetransmission receptors are blocked) or killed by drug chemicals(Koob, 2004). The conditioned learning memory stored during theinitial stages of drug abuse before addiction takes effect. In thiscase, intense memory and craving for the drugs arises whenever theaddict encounters cues about the drugs (Begley & Schwartz, 2002).
However,this intense craving may also come reflexively as a result of reduced‘dopamine’ transmitters in the brain. During the initial stagesof drug abuse, the natural dopamine transmitters are replaced withdrug chemicals transmitters that imitate the work of naturalneurotransmitters (Tannenbaum,2008).The resulting effect is that, these ‘foreign neurotransmitters’alters the communication and the reward system associated withdopamine effect (Berke, 2000). To this end, this means that addictssuffer from reduced ‘amount of dopamine level in the brain’ (drugchemicals) and thus must be urgently replenished in the brain hencethe compulsive urge. The vicious cycle of drug addiction continueseven when the addicts want to stop because of the changed brainchemistry and conditioned learning that make environmental cuestempting to recidivate to drug usage (Berke, 2000).
Addictionand how it changes the Brain functions
Dopaminehelps in the regulation of emotions, feelings, movements and feelingsof pleasure, however, when normal activation occurs the system‘rewards’ or elicit a pleasurable feelings in relation to theactivity engaged in (Berke, 2000). However, when overstimulatedthrough drug abuse, the neurotransmitter elicits a euphoric effectthat reinforces the repetition of drug abuse. Ideally, the brain iswired to repeat life-sustaining activities that results in rewardsand pleasures (Berke, 2000). As such, whenever the reward pathway isaroused, the brain record and keep the memory of the activityproducing a pleasurable feeling. In this way, the brain is wired toinfluence individuals’ repeat pleasurable actions over and overwithout much reasoning. This is how drugs eventually ‘teach’victims to abuse drugs (Hyman, 1994).
Oneadverse effect of drugs is that they lead to over-release of dopaminechemicals than the normal reward activities do. In addition, whenaddictive drugs are injected or smoked immediately, the release ofnatural chemicals occurs immediately, and their effects last longercompared to natural rewards (Koob, 2004). The resultant effect isthat, the production and pleasurable effect of the naturalneurotransmitters are decreased. The immediate and powerful rewardthat arises from taking drugs motivates victims to take drugs overand over. In normal circumstances, the brain regulates the productionof dopamine chemicals in the brain in case of overwhelming surges.The brain adjusts the level of neurotransmitters by reducing thenumber of receptors and the number of dopamine or otherneurochemicals (Tannenbaum,2008).
However,repeated drugs abuse lowers the ability of the reward circuit tofunction optimally, and this reduces the victim ability to experiencepleasure. This explains why most drug addicts fail to enjoy thingsthat were pleasurable before and instead they feel empty, lifelessand depression. The addict results to drugs to escape the feeling ofemptiness, depression and lack of interest in other activities(Hyman, 1994). These feelings are as a result of reduced dopamineeffect in the brain and lead the drug addict to a vicious cycle ofdrug abuse in an attempt to restore the dopamine function tonormality (Begley & Schwartz, 2002). After some time, the addictis forced to consume high dose of drugs in order to have the sameeffects as the natural dopamine at this level the victim is said tobe at tolerance level.
Long-termdrug abuse leads to the development of drug tolerance and subconsequent changes in the brain circuit and the neurons this has aneffect of long-term brain health problem (Tannenbaum,2008).For instance, the glutamate neurotransmitters are responsible forlearning and influencing the reward pathway, however, continued drugabuse leads to impaired learning and other cognitive functions(Berke, 2000). In the same line, long-term drug abuse leads tonon-conscious adaptation habits and memory. In particular, drugaddicts are exposed to conditional learning in which certain cuesfrom daily activities lead to drug cravings even when the actual drugis not available (Begley & Schwartz, 2002). The conditionallylearned ‘reflex’ behavior is responsible for the relapse after aperiod of drug abstinence. Chronic exposure to drug abuse alters thebrain structure ability to control behaviors associated with drugabuse (Berke, 2000).
Inaddition, increased tolerance to drugs leads to an increased dosageintake and compulsive addiction to drugs (Koob, 2004). At this stage,the person’s self-control and ability to make sound decisions iseroded. In the same line, the compulsive craving for drugs and useinterferes and destroys individuals’ involvement in dailyactivities such as the participation ion family and social life(Douglas& Martin, 2004).
Drugaddiction and behavioral changes
Theoverall effect of drug addiction is a changed brain capacity toprocess information and regulate one’s behaviors. In most cases,drug addicts’ behaviors are dictated by cravings for drugs at thislevel the brain is said to be hijacked, distorted cognitive andemotional ability. The distorted cognitive ability is a degradingaspect on an individual as the addicts face several perception andattitude problems (Begley & Schwartz, 2002).
Oneobservable behavior of addiction is increased obsession andcontinuation with drug abuse despite negative effects experiencedsuch as poor work performance, poor study, strained relations withthe family and other members of the society. The victims completelylose their control for addiction and when they attempt to stop theyexperience serious withdrawal symptoms such as irritability,restlessness and depression (Hyman, 1994).
Theaddicts experience memory loss and fail to remember their engagementin certain behaviors. In other cases, emotional changes associatedwith drug use predispose individuals to antisocial behaviors such asviolence and abusive language. Families’ breaks down as addictsfail in their parental and matrimonial duties. Addiction isassociated with uncontrolled obsession for drugs, and this may leadto misuse of financials resources to satisfy their addiction problem.In the same line, individuals’ life at work and other social placesdegenerate as addicts isolate themselves from other societal membersdue to depressions, feeling of emptiness and lack of cognition ontheir behaviors (Berke, 2000).
Inother cases, addiction leads to criminality acts such as robbery,domestic violence, kidnapping or destruction of property as addicts’source financial resources to buy drugs to satisfy their obsession(Begley & Schwartz, 2002). Furthermore, addiction leads todouble-mindedness and individuals suffer from adverse self-caremanagement and learning problems. Addicts are unable to change theirobsession even when they feel to stop, and this leaves themdiscouraged, depressed, confused and angry (Tannenbaum,2008).The desire to change the addiction behavior is overcome by obsessionto satisfy the cravings, and these forces create an internal war inthe victim’s mind. As such, quitting addiction becomes almostimpossible unless with assistance (Berke, 2000).
Needfor early intervention
Drugaddiction is not a permanent problem and intervention is possiblebefore addiction becomes an adverse compulsive problem. It most casesit is hard for most addicts to admit their addiction problem due tothe social stigma and shame associated with drug addiction. However,the first step towards meaningful recovery is admitting the problemand engaging in activities that distract the mind or individual fromassociating with drug use. Every year billions of dollars are used inmanaging drug abuse health related complications that can be reducedby addressing the problem of drug abuse.
However,the main purpose of intervention measures is not reducing the healthcosts associated with drug, but enhancing earlier intervention toavert the compulsive stage of drug addiction. Addiction is a complexphenomenon and influenced by myriad of factors in the addict’sbody, social life or environment. Addiction is progressive braindiseases that affect many people regardless of their age. As such,early intervention is effective in disrupting the course ofaddiction. The most important strategy in achieving earlyintervention against drug abuse understands the victims’ riskfactors such as physical or sexual abuse, mental illness, academic,family and social problems. Knowledge about risk factors surroundingan addict may be combined with knowledge of motivating factorsleading to drug abuse as a way of designing the appropriate strategyof intervention. Early intervention against compulsive drug taking isessential as it prevents many other problems linked to drug abuse.
Addictionis a progressive brain disease that starts casually and develops as ahabit and progresses as the addict use and associate with the objectof addiction. There is no aspect that can predict whether a personwould become addicted or not from the use of a particular substance.However, there are risk factors that predispose individuals toaddiction. These risk factors include the social environment,individual’s biological makeup and development. The brain is acomplex organ that plays an essential role of producing electricalsignals that combine with chemical neurotransmitters to enhancecommunication with other parts of the body.
Physiologically,the brain is tasked with a centralized coordination and control ofthe other parts of the body by enhancing the generation of muscleactivity and secretion of brain chemicals (hormones). The brain cells(neurons) have natural neurotransmitter chemicals and receptors thatenhance communication in the brain through special structures calledsynapse. These neurotransmitters are the glutamate, the serotoninand the dopamine chemicals among others. The neurotransmitters havecommunication pathways that allow brain cell communication andeffective transmission of information.
Drugshave chemical substances that tap into the brain communicationsystems and alter the way the brain cells (neurons) send, receive andprocess information in the brain. Unlike the naturalneurotransmitters, abused drugs over-stimulate the neurons leading toa powerful surges and overproduction of dopamine chemicals in theaccumbens, and this disrupts the communication networks. Abused drugsact as a shortcut to natural reward system. Repeated drugs abuselowers the ability of the reward circuit to function optimally, andthis reduces the experience of pleasure.
Long-termdrug abuse leads to the development of drug tolerance and subconsequent changes in the brain circuit and the neurons this has aneffect of long-term brain health problem. The overall effect of drugaddiction is a changed brain capacity to process information andregulate one’s behaviors. The victims completely lose their controlfor addiction and when they attempt to stop they experience seriouswithdrawal symptoms such as irritability, restlessness anddepression. The addicts experience memory loss and fail to remembertheir engagement in certain behaviors. Addiction leads to criminalityacts such as robbery or domestic violence. The desire to change theaddiction behavior is overcome by obsession to satisfy the cravings,and these forces create an internal war in the addict’s mind.
Drugaddiction is not a permanent problem and intervention is possiblebefore addiction becomes an adverse compulsive problem. The mostimportant strategy in achieving early intervention against drug abuseunderstands the victims’ risk factors and combines that knowledgewith addict’s information on the motivating factors leading to drugabuse as a way of designing the appropriate strategy of intervention.
BegleyS. & Schwartz J. (2002). The Mind and the Brain. United States:Harper Collins Publishers.
BerkeJD. (2000). Addiction, Dopamine, and the Molecular Mechanisms ofMemory.” Neuron Vol. 25, No. 3, pp. 515–32.
Douglas,RJ. & Martin, KA. (2004). Neuronal circuits of the neocortex.AnnualReview of Neuroscience27:419–451.
HaymanG. (2009). Addiction: A Disorder of Choice. UK: Harvard UniversityPress.
HymanSE. (1994). Why Does the Brain Prefer Opium to Broccoli? HarvardReview of Psychiatry Vol. 2, No. 1, pp. 43–46.
KoobGF. (2004). Neurobiological Mechanisms in the Transition from DrugUse to Drug Dependence.” Neuroscience and BiobehavioralReviews. Vol. 27, No. 8, pp. 739–49.
Kuhar,M. J. (2012). Theaddicted brain: Why we abuse drugs, alcohol, and nicotine.Upper Saddle River, N.J: FT Press.
Tannenbaum,L. (2008). Theaddiction conspiracy: Unlocking brain chemistry and addiction so youdon`t have to struggle.Bloomington: Author House.