Addiction as One of the Major Issues of the Human Race - Essay Example

Lecture 8: Addiction Addiction is one of the major issues that the human race is dealing with. This is because of the negative effects that are associated with consumption of some of the popular addictive substances including health problems, reduced cognitive functioning, mental health issues and health problems in children. Addiction is both a physiological and a psychological problem, and thus needs to be addressed at both ends. One of the important issues in responding to addiction is to understand the mechanism by which an individual experiences addiction. If we know this, we can devise means of helping people overcome the desire to consume the product that they are addicted to effectively. Common Features of Addiction Addiction to a substance is typically caused when the person experiences positive reinforcement for consuming the substance. Positive reinforcement is the experience of positive affect as a result of doing a specific act, each time the act is committed. The faster the drug produces the experience of positive reinforcement, the more addictive it can be. Addictive drugs typically cause the increase of dopamine in the nucleus accumbens. Some drugs do this by stimulating dopamine release by dopaminergic neurons in the mesolimbic system, and others do so by inhibiting the reuptake of dopamine by terminal buttons. PET studies with different drugs have provided evidence for these claims. Often, people also obtain negative reinforcement in the form of relief from adverse stimuli when they consume the said substance. Negative reinforcement entails the reduction of adverse experiences on committing an act. Addictive substances cause both these experiences to occur, and thus the person is motivated to continue to consume the substance. Addiction is usually characterized by both tolerance to the substance and withdrawal. Tolerance is a reduced sensitivity to the substance with regular consumption. Thus, the person has to consume larger amounts of the substance to achieve the same experience. It is believed that tolerance occurs because consumption of addictive substances affects the homeostatic mechanisms. This causes the body to produce the opposite effects to those caused by the drug in an attempt to re-create a balance. Thus, larger and larger doses are required to counter these changes and achieve a ‘high’. Withdrawal is the experience of symptoms that are the opposite of what the person experiences on consuming the substance in the event that they stop consuming it. Withdrawal is basically a state in which the changes in the brain functioning become evident once the effect of the drug has worn off. The longer a person consumes a drug, the more intense is the experience of withdrawal since the body becomes used to countering the effects of the drug, and thus, preempts it. Another important factor associated with addiction is the experience of cravings by addicts. Studies have shown that addicts experience lower activity in the prefrontal cortex and anterior cingulate cortex as compared to non users when they are not consuming drugs. On the other hand, when they encounter a stimulus associated with drug consumption, these areas become more active as compared to other times. Thus, the activity of drug consumption seems to be primed as a positive experience in the brain, and thus, the person feels excited at even the thought of the drug. Drugs like cocaine seem to produce significant changes in the brain. There have been observations in animal studies that lead to the belief that cocaine causes increases in dendrites in the nucleus accumbens and the prefrontal cortex which caused a long lasting activation of neurons. This increases the release of dopamine, and thus reinforces the drug habit. Commonly Used Drugs Although there are a wide variety of drugs that are used and abused by people addicted to them, not drugs cause severe addiction. Some drugs like caffeine are addictive, but not very harmful, and others like LSD are harmful, but do not cause addiction easily. Among the most popular addictive substances, we may count the opiates, cocaine, alcohol, nicotine and cannabis. Opiates like heroin are derived from a particular poppy plant and highly habit forming. Addiction to these drugs is related to other causes for concern such as risk for AIDS, criminal behaviors and health risks to children of mothers who use these drugs during pregnancy. Opiates seem to cause activation at both ends of the mesolimbic system and are associated with rapid release of large amounts of dopamine. This could explain the rapid habit forming concerns associated with opiates. Cocaine has been found to be a rapid and potent dopamine agonist, and thus leads to experience of euphoria that set in very soon after taking the drug. Cocaine has been shown to cause increase in dopamine that lasts for a significant time after consumption of the drug. Long term use also causes reduction in the number of dopamine transporters in the brain. Besides cocaine, methamphetamine and amphetamine also produce similar changes. Methamphetamine is associated with reduced dopamine transporters in the caudate nucleus for as long as 3 years after the person stops using. Cannabis, on the other hand, causes addiction by activating the THC receptors, particularly in the hippocampus which leads to dopamine release. This affects memory while producing euphoric experiences. Although nicotine is considered an ‘acceptable drug’, it provides cause for concern since it is associated with carcinogenic products and thus an addiction to nicotine can put an individual at risk for a number of health problems. Although it does not cause significant changes in behavior, nicotine is extremely addictive and people continue to abuse it even at significant risk to health and life. It does this by stimulating acetylcholine receptors and causing increase in dopamine release. The other drug that is considered acceptable in social settings is alcohol. Although it is associated with significant health risks to adults and children as well as social and familial problems; it is still the drug of choice in most social settings. Even low doses of alcohol produce mild euphoria. They also have an inhibitory effect on social controls while reducing discomfort and anxiety. This experience of both positive and negative reinforcement encourages the habit of consuming alcohol. It does this by affecting the NDA receptors and thus causing lowered cognitive functioning at one end while affecting GABA receptors at the other. Alcohol is an indirect agonist to both these sites and thus, causes significant changes in brain functioning. Heredity and Drug Abuse Hereditary and environment both play important roles in causing addiction. Although the role of environmental variables like stress, social status and education are well known, the role of hereditary factors are less understood and often misrepresented. Research shows that the likelihood of addiction is somewhat heritable, particularly for alcohol and nicotine. Addiction is also associated with other heritable personality factors like neurosis and impulsiveness. There seems to be a genetic trait that causes people to be vulnerable so that they become dependent on some substance easily as compared to others who do not carry this trait. There is evidence for this assumption through twin studies as well as through adoption studies. In particular, steady drinking (consuming significant quantities of alcohol regularly from a young age) is heritable in males. This is not to say that the interaction between hereditary and environment is not important. In fact, it seems that for a majority of addictions besides steady drinking it is the combination of these factors that must be taken into consideration. Therapy for Drug Abuse Understanding the mechanisms by which addiction occurs can help in identifying potential cures for different substances. Possible therapies include countering the effects of the drug on brain centers, stimulating dopamine reuptake, or blocking dopamine receptors. Methadone maintenance helps reduce opiate addiction by activating and occupying opiate receptors. Since methadone takes a long time to metabolize and is absorbed slowly, it does not provide the positive reinforcement caused by opiate drugs while blocking the action of these drugs simultaneously. This causes extinction of the desire to consume these drugs. Cocaine addiction can also be reduced by giving medical compounds that block the effect of the drug and cause an extinction of the response. These techniques inhibit the drug’s ability to induce dopamine release and thus, the ‘high’ and euphoria associated with them cannot be experienced by the person. Nicotine is treated in a similar manner by providing nicotine through alternate means till the individual stops associating the effects of nicotine with the act of smoking. The dose of nicotine is then slowly reduced till the brain adjusts to lower and lower levels of the drug and finally achieves pre-addiction responses. Serotonin agonists can help counter the need for alcohol, and opiate antagonists have also been found useful in dealing with alcohol addiction. Although these medicines can provide relief from addiction when used carefully, the role of counseling in treating addiction cannot be denied as it helps in addressing the environmental problems. The most effective treatments combine medical and talk therapy to provide all round support for the addict. Read More