Contribution of Nature/Nurture to Drug and Alcohol Abuse - Essay Example

Contribution of Nature/Nurture to Drug and Alcohol Abuse Introduction Epidemiology, the distribution and determinants of disease occurrence involvingalcohol, tobacco, and other drugs (ATOD), plays an increasingly important role in planning and programs involving substance use, abuse, and dependence. Traditionally, the search for genetic influences in any complex disorder begins with studies of families, twins, and adoptees affected with the condition. These investigations can provide preliminary evidence on the probable importance of genetic factors and serve as the foundation for subsequent research. People over the age of 18 who have at least one biological parent with severe and repetitive life problems with alcohol are referred to as adult children of alcoholics. Because they have family and genetic ties to an alcoholic, these people carry an increased risk of severe alcohol problems themselves, from two to four times that of children of nonalcoholic parents (Rutter, 2002). When children of alcoholics reach adolescence or adulthood, they might be slightly more likely to have problems with marijuana-type drugs or with stimulants such as cocaine or amphetamines. In the fields of psychology and psychiatry, there is interest in tracing the origin of certain personality traits thought to be common among adult children of alcoholics. These traits may or may not come about because of specific alcohol-related experiences in the childhood home. They may instead stem from the general childhood environment, in which an individual was raised, additional psychiatric conditions among the parents, or general factors associated with a disordered childhood home (Rutter, 2002). Nature There has been steady accumulation of evidence that there is familial aggregation in alcohol abuse and dependence, which seems to be in part determined genetically. The results of more than four decades of family, twin, and adoption studies in alcoholism, although not unanimous, conjunctively provide impelling evidence that genetic influences play important roles in this and related drug abuse disorders. More specifically, 40% to 60% of the variance in heritability of alcoholism can be attributed to genetic factors (Plomin and Asbury, 2005). Family studies which draw upon the basic design of the assessment of risk for developing the disorder in relatives of probands, who are individuals manifesting the phenotype or trait with the rates in the relatives of control groups have demonstrated that that rates of alcoholism are substantially higher in relatives of alcoholics than in relatives of nonalcoholics, with children of alcoholics demonstrating a four- to fivefold increased risk for developing the disorder. This increased risk appears to be relatively specific for alcoholism, with most family studies showing an increased rate for the disorder among relatives of alcoholic probands, while the same group does not show higher rates of other mental disorders, such as schizophrenia or bipolar disorder. Several major twin studies have directly addressed the concordance rates for alcoholism in identical versus fraternal twins. These studies have found that the concordance rate for alcoholism in male monozygotic pairs was greater than that for dizygotic twins (Stallings et al., 2005). This led to search for a common genetic factor that might be inherited and would increase the epidemiologic risk of these disorders. Family, twin, and adoption studies indicate that genetic variation influences the risk of abuse on alcohol and nicotine. Studies on other illicit drug abuse indicate both genetic and familial contributions to the development of illicit substance use disorders. The commonly held hypothesis on substance use disorder is that common genetic risks may explain at least partly their comorbidities. Thus these indicate that the vulnerability to abuse and addiction is at least partly determined by a genotype, the characterization would most probably be multifocal. The question remains whether these point to vulnerability to a specific drug of abuse, or to a class or drugs, or to psychoactive substances in general. If the last possibility is true, which is in reality true for many abusers, then the same mechanism may explain the abuse of all the drugs. The phenomenon of co-occurrence of drug abuse has been studied in detail. These suggest that at least for some drug abusers, the first specific drug of abuse is just incidental, may be determined by environment or chance. The effect of the drug motivates the individual, and to obtain the desired effect, the abusers use different drugs. It has been observed that individuals to terminate abuse of alcohol often use cannabis, no risk factors have been identified for a particular drug of abuse, and there is a little chance that abuse of a particular substance is related to specific genetic factor (Goodwin, 1989). The search for specific markers of gene locations through linkage analysis and allelic association studies have revealed possibility of abuse susceptibility loci in 1, 2, 7, and 16 chromosomes, but thus far evidences are inconclusive, so specific genetic markers have not yet been recognised. Association studies have also been conducted on dopamine and serotonin receptor genes and aldehyde dehydrogenase and alcohol dehydrogenase genes. These also provide indirect proof that a genotypic link does exist in determining predisposition to addiction to alcohol (Stallings et al., 2005). Nurture Genetic influence on alcoholism has been acknowledged to be partial, and it has been suggested that a genetic predisposition may combine and interact with other factors that are determined by the environment, which has been traditionally referred to as the nurture factor in drug abuse. Substance use takes place within an evolving sociocultural environment that mediates which substances are available, their desirability, and their acceptability. Accordingly, the drugs to which persons are exposed and their reactions to them are strongly influenced by the person's place in the prevailing societal environment. Drug abuse and its attendant problems are embedded within a complex evolving sociocultural context. The illicit drug-of-choice changes over time. More centrally, the impact of drug use in a person's life is strongly mediated by the person's social position. Illicit drug abuse is associated with particularly widespread devastation in disadvantaged inner-city communities. Members of these communities have limited social capital, resources to draw upon when their lives are stressed by crisis. It is to be accepted that many such environmental factors emanate from families. It has been observed that early predisposing factors active in childhood can predict future alcoholic behaviour in early adulthood. For example, parental marital conflicts, low family cohesion, and poor attachment to parents are frequently coexistent with a genetic trait if there be any, and these are pure environmental factors. Adoption studies have solved the problem somewhat, and it is currently known that environmental factors play important roles in addictive behaviours. Environment comprises of external factors that may influence of psychological status of the person. The stress and tension that arises from the environment may lead to the initial drinking episode, and the desire to have this feeling repeatedly may lead to a situation of problem drinking behaviour. There are a host of other environmental influences that contribute to the risk for alcohol independence. Although at one particular time, one specific factor seems predominant, it is highly likely that each environmental factor adds a small proportion to the vulnerability to repetitive problem with alcohol and abuse. These factors are drinking patterns of peers, higher availability and access to alcohol, liberal familial and social views about drunkenness. Peer influences have also been implicated in many other drugs. Nature/Nurture Any use of illegal substances that have no recognized medical purpose is generally regarded as abuse. Thus the best general definition of drug abuse is the use of any drug in a way that does not follow medical advice or that does not conform to a particular culture's accepted usage. Therefore it is regarded as a behaviour. To understand this behaviour it is widely accepted that both nature or heredity and nurture or environment has influences. In this context it is to be noted that natural traits are often nurtured by the environment and they reciprocate. Thus the concept is not nature versus nurture, rather it is nature and nurture. Translated into the language of chromosomes, if nature indicates genotype, the term nurture indicated phenotype (Cooper, 2001). This is an attempt to examine reality where brain and behaviour combine together through social experience. In reality, the effects of nature are dependent on the status of nurture when the human being develops. Therefore the outcome that nurture demonstrates is based on the innate nature of the individual. Thus it can be contemplated that heritability would also change with the change in the environment. Genetically, the phenotype is nothing but the product of genotype and environment, or simply expression of the genotype. Eisenberg has rightly said, "Gene effects depend on the environment in which development occurs. Environmental effects depend upon the constitution of the organism on which they act (Eisenberg, 1998)" This can be viewed with an example of alcoholism. Currently, several overlapping approaches are in use to categorize alcoholics into various clinical phenotypes or subgroups based on family history, age of onset, clinical symptoms, and personality traits. There are two forms of alcoholism that could be distinguished on the basis of the biologic parents' pattern of alcohol abuse and the degree to which postnatal environmental factors affected the inheritance of susceptibility to alcoholism. Combining results from a variety of personality, clinical, and neuropsychopharmacologic studies with the genetic epidemiologic findings, it has been proposed that gene-environment interactions play a great role in alcoholism and hence related abuse of drugs (Plomin and Asbury, 2005). Conclusion Research and advance in knowledge of alcoholism and other drug abuse in population now suggest that genetic traits of an individual predispose him to get addicted to alcohol or other drugs. But the manifestations of alcohol or drug abuse ultimately a phenomenon that needs interaction of environmental factors that determine behavioural and personality traits, and ultimately drug abuse behaviour is manifestations of all these factors conjointly operate to cause a problem drug behaviour, and knowledge about this may help in designing interventions. Reference List Cooper, B, (2001). Nature, nurture and mental disorder: old concepts in the new millennium. The British Journal of Psychiatry; 178: s91 - s101. Eisenberg, L., (1998). Nature, Niche, and Nurture: The Role of Social Experience in Transforming Genotype Into Phenotype. Academic Psychiatry; 22: 213 - 222. Goodwin DW., (1989). The gene for alcoholism. Journal of Studies in Alcoholism; 50: 397-398 Plomin, R. and Asbury, K., (2005). Nature and Nurture: Genetic and Environmental Influences on Behavior. The ANNALS of the American Academy of Political and Social Science; 600: 86 - 98. Rutter, M., ( 2002). The interplay of nature, nurture, and developmental influences. The challenge ahead for mental health. Archives of General Psychiatry; 59 :996-1000. Stallings, MC. et al., (2005). A Genome-Wide Search for Quantitative Trait Loci That Influence Antisocial Drug Dependence in Adolescence. Archives of General Psychiatry; 62: 1042 - 1051. Read More