Biological Aspects of Drug Addiction  Term Paper

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The process of neuroadaptation

There are two main processes that do contribute to the development of addiction as well as the reinforcement and the process of neuroadaptation. The process of reinforcement occurs when a rewarding stimulus such as alcohol or other drugs such as AOD causes induced euphoria. This could also be a relief from an unpleasant condition or state such as anxiety which usually increases the chances of a behavioral response such as the use of AOD. Neuroadaptation refers to the various compensatory moves and adjustments in which the brain makes deliberate attempts to continue with its normal function irrespective of the fact that it is under the influence of alcohol. The process of neuroadaptation and reinforcement which occurs simultaneously does appear to underline the initial acute response (short-term) to the drug under use as well as the establishment of chronic (long-term) craving that is often characteristic of addiction. It is worth pointing out that certain behaviors that are neuroadaptive makes changes could be permanent thus producing a continuous sense of discomfort that usually causes a relapse some time later after an individual stops to drink (Koob et al. 1993).A more common manifestation of the process of neuroadaptation is the experience of an acute syndrome that is consistent with withdraw which follows the abrupt stop to a heavy bout of drinking. As a reaction to the continued alcoholic content in the brain, a compensatory mechanism is initiated in an attempt to overcome the inhibition of alcohol by NMDA receptors. This is through the increase of the functions of NMDA through a process of up-regulation. At the time which the alcohol leaves the synapse, there is a combination of the up-regulated transmissions which are excitatory as well as the down regulation of the inhibitory transmission which results in the brain being hyper excited. A characteristic which is part of the withdraw syndrome as outlined by (Littleton,1998).The process of withdraw triggers the body to respond to the stress created. This leads to the elevated levels of stress hormone, cortisol in the blood stream. An excessive level of cortisol leads to the death of neurons in the hippocampus which leads to an increased risk to infection, alteration of energy metabolism and the promotion of disorders associated with mood and intellect as pointed out by intellect (Adinoff et al. 1998). The process of neuroadaptation can be thought of using the theories of counteradaptation which includes processes like tolerance that are started by the brain in order to oppose the particularly acute effects of alcohol. Neuroadaptation however includes and refers to sensitization which is referred to as an increase in the response to the effects of a drug as a result of repeated administration. Should the process of sensitization lead to an increased AOD consumption then addiction is likely to occur. The process of sensitization is more likely to result as a result of intermittent and repeated exposure to the AOD's.Tolerance however is likely to occur as a result ot continue exposure as pointed out by exposure (Robinson and Berridge, 1993). Should an addict withdraw within a short time (acute), then motivational effects are likely to occur as pointed out by (Koob and LeMo et,1997).there are various neurological structures that have an association with the reinforcing action of alcohol as well as other drugs.They may involve certain common neural circuits that form separate entity at the base of the forebrain. This is the extended amygdala as pointed out by (Alheid and Heimer,1988).Amygdala refers to a complex structure that is made up of several smaller structures and is situated near the base of a human's frontal area of the brain. The amygdale system has an extensive arrangement of connections to various brain regions that play an integral role on the reinforcement as well as the reward as pointed out by ( Diamond and Gordon, 1997).


All factors remaining constant, studies shows that the overuse of alcohol is most common among young individuals. A survey revealed that 15.9 million American are classified as "heavy" drinkers and another 27.4% of the 2009 high school classes were reported to have drunk at least one a month. The survey was annual (DINF,2010)

The addiction process of stimulants

The addiction mechanism of stimulants such as cocaine has been a subject of late scientific research. New studies such as have shown that there is a more detail regarding the way stimulants acts in the body of the users. In order to illustrate the process of cocaine addiction, we use the latest model advanced by scientists (NIH,2010).

Researchers have demonstrated how the pleasurable effects of cocaine are achieved and whuy it is so addictive. They have proven that it affects certain areas of the brain. They have shown that cocaine affects a region in the midbrain referred to as ventral tegmental area (VTA).The various nerve fibres tha originate in the VTA do extend to another region referred to as the nucleus acumens.An increased level of dopamine, a neurotransmitter increases brain activity in the brain's nucleus accumbens. During the normal process of communication, dopamine gets released by a neuron into a small gap that exists between two neutrons (synapse).This then binds to a specialized group of proteins referred to as dopamine receptors which resides on the nearby neutron and then sends the signal to the next one. The use of stimulants such as cocaine interferes with the normal process of communication. Scientists have found that cocaine works by blocking the process of removing dopamine from the synapse. This results in an accumulation of dopamine at the synapse and hence an amplification of the signal being transmitted. This causes the initial euphoria which is often reported b cocaine abusers (NIDA,2010).

Symptomology of stimulant addiction



Loss of appetite

High energy level and euphoria

Sudden depression



Loss of energy

Weight loss

Pupil dilation

Involuntary muscle twitches






The use of cocaine has sharply fallen since 1080's when it was highest. The year 2008 saw the number of Americans who admitted to using cocaine stand at 1,855,000.A figure which was just a third of the earlier 5,686,000 who were reported to be users in 1985.This figure is also about 25% below the totals for 2006 (DINF,2010)

Comparison and contrasting of the mechanism

It is clear that the process of addiction by stimulants and depressants are quite different in terms of the overall mechanisms and processes.The similarity comes in the fact that certain receptors such as dopamine are present in both processes as well as regions of the brain such as nucleus accumbens


A knowledge of the mechanisms of addiction is integral in the process of coming up with treatment of drug addiction. It is therefore crucial to come up with the best ways of treatment that is derived from the existing research work.


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