California Southern University
April 26, 2011
Drug addiction is a complex disease of the brain. There are many neurological
factors that are involved in this disease. In order to understand the individual
differences that can influence one??™s propensity for this disease, I will first define
the disease and will provide physiological factors that come into play. Then I will
analyze information from recent scientific experiments and data to determine
how individual differences affect one??™s predisposition for addiction.
What exactly is addiction It is certainly not a new disease, but there has
been much research done recently, which has changed the way this disease is
viewed and has greatly improved treatment and recovery for those who suffer
from it. How do individual differences affect the incidence of addiction I plan to
present the most current information available to satisfy the answer to this
The best definition I have found for addiction is, ???the uncontrollable
compulsive drug craving, seeking, and use, even in the face of negative health
and social consequences??? (Murray, n.d., para. 1). Another definition is ???a
progressive debilitating and potentially fatal brain disease??? (Stone, 2010, para.1).
Addiction should be viewed as a recognized brain disease, which is expressed
in the form of compulsive behavior (Murray, n.d.). It is chronic,
recurring, and fatal. Many people believe addiction is a character
weakness. Research contradicts this erroneous belief. There is no cure
for addiction, but recovery is certainly possible.
What happens in the brain of an addict Long term use of drugs changes
the structure and the function of the brain in basic and also long acting
ways that often persist after the individual stops using them. When a drug , such
as cocaine, enters the body, it dissolves and is transported through the
circulatory system to all areas of the body .In the ???feeling center??? of the brain it
causes an increase in the dopamine level and also, to a lesser degree, nor-
epinephrine. This causes the brain receptors to get lots of ???hits???. This causes
much stimulation, creating a feeling of energy, or a high. As the
ingestion of the drug increases, the dopamine is used up, and more
receptors get hit, leading to dopamine depletion. As the receptors
continue to get many hits, they build a shield to protect themselves against the
effects of the dopamine, causing the addict to have to use more and more of the
drug to get the same high. Narcotics and heroin act by hitting the opiate
receptors. This causes the bypass of the natural opiate system, which uses
endorphins and enkephalins as neurotransmitters. After continued use, the body
subsides in producing its own natural endorphins as neurotransmitters. Again,
the continued use of opiates/heroin causes the receptors to become less sensitive
and more of the drug is needed to get the same high (Stone, 2010).
There is also a genetic component to addiction, mainly in the disease of
alcoholism. Prior research has shown a significant genetics influence on a person??™s
response to alcohol. New research has identified three chromosomal areas in the
human genome that holds genes that affect a person??™s low level of response to
alcohol. Three locations were found that had the largest evidence for genes that
affect the level of response to alcohol. These were chromosomes 10, 11, and
22 (???A Primer???, 2010).
There is also an element of ???survival of the species???. Actions that influence
the ???rewards center??? of the brain are necessary for human survival. Some of
these actions are the intake of nutrients and procreation. When the brain reward
system is activated, changes occur such as mood elevation, intense pleasure and
even euphoria. These affects help direct behavior toward natural rewards (???A
Primer, 2010, para.9). Caffeine, nicotine, and alcohol all activate the brain reward
system, as do addictive drugs. The difference is that with addictive drugs, the
activation is much more intense and can cause the victim to actually crave the
drug and to focus their activities around taking the drug. The complexity of
this brain disease is not abnormal. No brain diseases are simply biological
in nature. All brain diseases, including Alzheimer??™s disease, schizophrenia, stroke
and depression, include some behavioral and social aspects. (Murray, n.d.).
It is apparent that addiction is a complex disease having multiple influences
on the body. It is certainly a disease of the brain affected by genetics, brain
physiology and the survival mechanism of the reward system. There are also
differences which each individual has which can further the understanding of
addiction. Some of the differences are based on environment, genetics, culture,
family history and behavioral traits.
???All behavior, thinking, and feeling are controlled by actions of molecules in
the brain. Brain molecules can be changed by experiences in our environment,
diseases, drugs, and genes??? (???A Primer???,2010, para. 9).
One??™s environment can play a large part in the addict??™s disease. ???The social
environment can persuade normal and decent people to perform noxious and
anti-social acts??? (Stelzer, n.d., para.6). This was proven by Stanley Milgram??™s
study of obedience to authority. A person??™s environment can also trigger a
relapse. The people, places, and things that an addict associates with using, if
reintroduced, can trigger the brain??™s intense craving for the drug.
The importance of heredity cannot be overlooked. There is a lot of new
evidence that is favoring nature over nurture. Many studies on twins suggest the
importance of heredity (Stelzer, n.d.). Alcohol research has been finding that a
portion of the vulnerability to alcoholism is genetic. The researchers have
discovered that approximately 50-60 percent of the risk for developing
alcoholism is genetic. They are also learning that genes do not predetermine,
they only increase the risk (???A Primer???, 2010). No single gene is responsible
The culture in which a person is raised will also influence their tendency
toward addiction and should not be ignored. An example of this is the Asian
American culture. This culture has a much lower incidence of drug abuse
and alcoholism. This may stem from their beliefs in respect for one??™s parents,
shame as a behavioral control, and the importance of self-control within this
culture. The American Indian culture presents a different view. This culture has
a mortality rate from alcoholism which is 579% greater than all other races.
This may be attributed to the acculturative stress which this culture experiences.
This can be defined as the demands to integrate into and identify with a more
dominant culture. Combine this with the low income of most Native Americans,
the lack of education, and the loss of historical tradition, and one can began to
see the massive influence these stressors are having on this culture and their
cultural response in general is to abuse alcohol (Stevens, 2009).
Family history plays a role in that many families use alcohol with meals,
relaxation and celebrations. This becomes the norm for this family, to use
alcohol very often if not daily. This can be found in many Midwest, and Irish-
Catholic families. This seems to be the norm for one who knows only this way of
life, especially from early childhood.
Behavioral traits may also play a role in addiction. By examining the
behavior of rats, it has been shown that some rats are less cautious and self-
restrained than other rats. They exhibit the trait of unusual risk taking.
In another experiment with rats, a propensity to respond to cues may make
them susceptible to becoming conditioned to the cues associated with drug
taking (Kolb, 2011).
After studying addiction, I have learned many things. Addiction is a brain
disease. It alters the chemistry of the brain. There are many genetic factors that
predispose one to this disease. The pleasure principle of addiction can be traced
back to man??™s basic survival instinct, which has kept our species flourishing. In
addition to that, addiction is affected by an individual??™s environment. Their
culture plays a big part, too. The inner workings of their family of origin play a
role. There are certain behavioral characteristics that also come into play.
Despite all of these influences, addiction can be stopped, and recovery is then
possible. In order to help an addict in recovery, it will be important to learn all
about these individual differences and the basic definitions and workings of this
Kolb, Bryan. (2011). An Introduction to Brain and Behavior.USA, Worth Publishers.
Murray, Stephen, Rev. (n.d.). The Disease Concept and Brain Chemistry of
Alcoholism and Drug Addiction.www.nicd.us
A Primer on Drug Addiction. (2010).
Stelzer, Leigh. (n.d.) Individual Differences.
Stevens, Patricia. (2009). Substance Abuse Counseling: Theory and Practice. New Jersey, Pearson Education, Inc.
Stone, Michael MD. (2010). The Chemistry of Addiction. www.cornerstonesocal.