Cocaine Addiction

Biology 202
2004 Second Web Paper
On Serendip

Cocaine Addiction

Shirley Ramirez

Addiction to cocaine is amongst the most severe health problems facing the United States. For example, in 1997 there were approximately 1.5 million Americans twelve years and older that were chronic cocaine users (1). The question presented, then, is given how negative and damaging cocaine is to a user's health and society as a whole why is it that people addicted to cocaine have great difficulty quitting? One possible answer to this question is biological; namely that cocaine alters the normal state of the brain making it difficult to quit. Two properties which make cocaine one of the most addictive popularly used drugs is that it is reinforcing when administered acutely, but also produces obsessive use if administered chronically (2). However, arguments can be made that cocaine addict's perpetual abuse of the drug is, at least in part, a result of social factors. In other words, it is not only cocaine's biological effects on the brain that makes it difficult for addicts to give up the use of the drug. If the fact that perpetual cocaine abuse resulted from biological and social factors was better understood and more widely accepted, we would be able to better help cocaine addicts quit using the drug.

In order to combat cocaine addiction we must first understand what addiction is. The World Health Organization defines addiction as a "behavioral pattern of compulsive drug characterized by overwhelming involvement with the use of the drug, the securing of its supply, and a high tendency to relapse after withdrawal (3). There is an established sequence of events that defines addiction. First, there are the euphoria effects that the drug of abuse produces. Second, tolerance develops, meaning that the addict needs more and more of the drug to produce an affect. Finally, there is physical dependence, in which the addict feels they need the drug to survive; they are addicted. Under this definition a person can theoretically be addicted to almost any substance, for example chocolate. However, while it may be difficult for a person to refrain from eating chocolate all would concede that it is much more difficult to quit cocaine once addicted. The question is why this is the case.

Like chocolate, cocaine is associated to the nucleus accumbens. The nucleus accumbens is known as the brains pleasure center since several studies demonstrate that pleasurable stimulus, such as sex, food and other drugs of abuse, cause an increase in activity in this are of the brain (4). The mesoaccumbens dopamine (DA) pathway, which extends from the ventral tegmental area (VTA) of the midbrain to the nucleus accumbens (NAc), has been linked to the reinforcing effects of cocaine. This was found through intracranial self-stimulation, a process which consisted of implanting electrodes into different regions of an animal's brain, and demonstrated that when dopamine is involved reinforcement of the behavior increased (2). In essence, this shows that pleasurable events, such as sex, chocolate consumption and cocaine abuse are accompanied by a large increase in the amounts of dopamine released in the nucleus accumbens.

Given the similarities in which pathways are activated, why is it that the use of cocaine is more difficult to quit when compared to other fore mentioned pleasurable events? A person addicted to chocolate and cocaine both will have excess amount of dopamine released from the nucleus accumbens, but both individuals will react to that biological circumstance differently. The initial effects of both the chocolate and cocaine will be euphoria, but after these pleasurable stimuli are removed the individual addicted to cocaine will experience very severe physical withdrawal effects, whereas the individual addicted to chocolate will be able to cope with its loss. Is that due to the fact that the excess dopamine is derived from different pathways? Is the initial euphoria effect stronger in cocaine? It is clear that at least part of the answer lies in the way that cocaine biologically affects the brain.

In the dopamine pathway of individuals not addicted to cocaine, dopamine is released by a transmitting neuron into the synapse, where it binds to receptors in the postsynaptic neuron, propagating a signal. After the binding has occurred, the dopamine reuptake transporters (DAT) of the presynaptic cell reuptake the remaining unused dopamine back into the cell (5).

As mentioned earlier, cocaine's major effects are thought to be due to action on dopamenergic systems. In addicted individuals, cocaine has the ability to bind to the dopamine reuptake transporters (DAT), therefore, blocking them from reuptaking dopamine, consequently resulting in an accumulation of dopamine in the synapse. This accumulation of dopamine causes continuous stimulation of the post-synaptic neuron, resulting in the euphoria commonly reported by cocaine abusers. Cocaine also affects serotonin and norepinephrine reuptake transporters, enhancing the levels of these neurotransmitters in the cell (6). The latter is important since researchers speculate that more than one neurotransmitter is responsible for the pleasurable feeling cocaine provides. In addition, cocaine simulates the "fight or flight" response, by increasing activity of the sympathetic nervous system, due to its action on norepinephrine transport (7). Some of the increased activity is illustrated by constricted blood vessels, dilated pupils and increased heart rate as well as blood pressure. In other words, cocaine has a great variety of biological effects on the brain which lead to a very strong addiction.

Cocaine's biological effects on the brain also make it very difficult for an addict to quit abusing it. When an individual becomes addicted to cocaine the repeated euphoric responses to the drug alters the brain, creating a dependency within the addict's brain. The individual will therefore, continue to take cocaine to re-experience the extreme euphoric effects of cocaine. Also, addicts continue to take cocaine because after cocaine administration dopamine levels decrease significantly compared to normal pre-consumption levels. Therefore the addict feels a "low" and the immediate response to ease this low is to administer more cocaine to raise the dopamine levels. It is clear then that a significant reason why addicts find it difficult to quit cocaine is because their brains are biologically altered. In a sense, it could be said that the brain is no longer biologically whole in that it no longer produces dopamine levels in the way it once did.

The fact that addicts develop tolerance or sensitization to cocaine also makes it difficult to quit abusing the drug. After chronic administration of cocaine the brain reduces the number of dopamine receptors on the dendrites of neurons. As a result, there is less stimulation of the nerves in the dopamine pathway. This physical change in the brain alters the way it responds to different doses of cocaine. This is where tolerance develops in many addicts, wherein a larger dose is needed to attain the same euphoric effects initially experienced. Other addicts experience sensitization, in which the user becomes more responsive to cocaine without increasing the dose. Recent research has investigated why some addicts experience sensitization and others tolerance. Is it due to different brain make-up or is it due to manner of administration of the drug? In either case it is still clear that both of these phenomenon's present yet another biological hurdle that a user must overcome when quitting cocaine.

However, the obstacles a cocaine abuser faces when trying to quit her or his abusive tendencies are not exclusively biological. The cocaine abuser also faces several psychological/social barriers in the path to becoming drug free. After constant administration of cocaine the phenomenon known as place conditioning becomes activated. The place conditioning theory suggests that the environment in which you administer cocaine will be associated with the act of cocaine use (8). For example, if a drug addict purchases cocaine at a specific grocery shop and experiences the drug effect shortly thereafter, eventually the grocery shop becomes linked in the mind of the drug addict to the rewarding effects of cocaine (8). This has been extensively proven in animal models, where rats return to the environment where they administered cocaine. In humans, place conditioning might cause addicts to have an overdose. This is because addicts are accustomed to administering the drug in a particular environment and begin to associate the rewards of the cocaine to the environment itself. Therefore, in a different environment, not associated with the administration of cocaine, the same dose will produce a larger effect because the environmental cues are not associated with the rewards of the drug. Perhaps more significantly, this demonstrates that the environment can itself lead to a greater addiction to cocaine since the environmental stimuli will constantly remind the user of the pleasurable effects of cocaine.

It follows then that the difficulty in quitting cocaine cannot be 100 percent biological. If addiction was only biological then place conditioning would not be an issue. All too often the view that brain=behavior, meaning, that brain elicits behavior, is acceptable as complete. However, in this instance the environmental stimulus has the power to elicit brain stimulation ending in craving of cocaine, demonstrating that biological and social/environmental factors are deeply intertwined and each play a role in rendering cocaine incredibly addictive.

Most relapses occur when an individual returns to the environment where he/she would administer the drug. Exposure to such cues and stimuli reminds the addict of the feeling and taste of cocaine therefore, they will begin to crave cocaine. But how exactly do the environmental stimuli trigger the drug craving? Recent research has brought forth that the extended amygdala might play a major role in "in context" craving. The extended amygdala is part of the limbic system, a region of the brain associated with memories and emotions. Researchers at the National Institute on Drug Abuse believe that it is in the extended amygdala where memories relating to drug administration are converted into craving for that specific drug (8). As mentioned earlier, memories give rise to craving when the environment where cocaine is abused becomes a conditioned stimulus. The latter is the reason why so many people relapse and continue to be addicted.

Unfortunately, to date there is no one treatment that will eliminate addiction or all characteristics associated with addiction. Perhaps finding a treatment to cocaine addiction has not been overly successful because researchers do not fully account for the biological and social factors which make it extremely difficult to quit using this drug. It follows that a combination of medical treatment (to address biological factors) and counseling (to address the social factors) would be most beneficial to addicts. Drugs are being developed aiming at blocking cocaine from binding to the dopamine transporters allowing for the reuptake of dopamine, which may prove very effective at stabilizing the biological factors. However, such medication alone will not suffice. In terms of combating the social factors, the most effective counseling is "cocaine-specific skills training" which consist of identifying the environments and stimuli that triggers craving in order to control and avoid such stimuli (4).

The problem of cocaine addiction in America will not disappear overnight. However, a greater understanding of why cocaine addiction is so uniquely strong will help lead to discovering a better understanding of how to combat it. It is important to understand that both biological and social factors work together to form cocaine's powerful addiction. As such any effective treatment must aim to counteract both. As such, we must first fully understand cocaine addiction and its properties before we can hope to eradicate it.

 

References:
1) NIDA Home Page,Various information about Cocaine. Specifically Statistics.

2) Article on Addiction, Describes biology of Addiction.

3) Substance Abuse Facts

4) National Institute of Health., Various information about cocaine addiction and health hazards, treatments etc.

5) Effects of Cocaine Biologically

6) More information about Cocaine and how it effects your neurotransmission

7) Research on Cocaine

8) Amygdala and Memories

 

 

Continuing conversation (to contribute your own observations/thoughts, post a comment below) 09/27/2005, from a Reader on the Web As a 16 year old watching many of my friends, including some of my own family members snort their lives and pocketbooks away, I believe that the best way to combat and control the cocaine addiction this country is exposed to, is to start with the young population.... 12+ in age preferably... If the money flow is controlled and watched by parents and even the government in general, the ability to purchase the drug in the first place will be greatly reduced... We cant be naieve... We know just as well that the government isnt doing much to control the problem as it is... I guarantee Kilos and Kilos of the drug are brought in to the country or even harvested on our own soil daily... Be smart. Follow the drug addictee's nose... Only time shall tell whether or not the future plans on this problem even surrounding me, will elimiate an almost invincible foe... I have the feeling the government and local law enforcement agencies are going to need to hire a few more hands to combat this problem... Until such a time, we have to rely on the fact that yes, yes it does indeed kill you... slowly, but almost certainly... One day, the addictees will realize that the end outcome of this social and biological addiction is their own downfall... and lastly... The word on the streets and from the people I know who do infact snort almost a gram of that crap daily is that some of the cocaine coming into california is laced with some particular poison, which when snorted will cause an almost instantaneous death... Perhaps this, among other factors including that soon enough this dirty cocaine will reach all corners of the united states... a subtle warning brought on by the poor souls already dead from the crap... Glad to make my point... Sincerely,

 

 

I once was a user of this "crap" as well. All my life (before I used it) I always promised myself that I would never even look at it because I watched my brothers life go down the drain from it along with a few of my cousins lives. After seperating from my husband I met someone who was a user and I thought I would just try it for the fun of it. It doesn't work like that!!! Within a couple months my whole life was based around smoking coke. I had a job and was attending college but I couldn't get out of bed in the morning to go because I had been up till 5 in the morning smoking that crap.So I ended up dropping out of college and I quit my job! Luckily I wasn't too far gone. After it seems that I had hit rock bottom I found myself on my knees preying to God to forgive me for my sins and to help me outta this mess, That very same day I was healed from my coke addiction and my life is now based around the Lord.You may be able to try and heal yourself but The Lord is the only One who can truley heal you. If you do it yourself then you'll only end up substituting it for something else. You have to have faith that the Lord has (by grace) already healed you then you need to receive it and ONLY then will you be healed and delivered from that addiction or from ANY stronghold that satin may have on you. Just think about this... It's worth a try right? God Blesses! ... Cheryl, 5 March 2007