The article “Who is at risk for alcoholism” written byForoud, T., Edenberg, H.J., and Crabbe, J.C. deals with genetic factor which may lead to alcohol dependence. The World Health Organization estimates that nowadays alcohol is the cause of 1.8 million deaths (3.2 % out of all deaths) and of 5.3 million disability adjusted life years (4% out of the total) worldwide. In many counties alcoholism is considered to be one of the major problems. The biological underpinnings of alcohol dependence have been studied by The National Institute on Alcohol Abuse and Alcoholism (NIAAA) which was founded 40 years ago. First genetic studies were concentrated on defining whether environmental and genetic factors contribute to the risk for alcohol dependence. Since it was stated that genes do play a role in alcohol dependence, NIAAA began to study humans and animals in order to understand the genetics of alcohol consumption and dependence.
Family studies have shown that alcohol dependence and other common diseases are caused by genetic factors. Several strategies were developed with the aim to identify genes which play an important role in linkage analysis, and differences in the risk of alcohol dependence. There exists more than one position form of the genes. It has been hypothesized that alcohol addicted people within a family share many alleles of risk, some of them which increase alcoholism risk are in chromosomal regions inherited by alcoholic members of the family. Chromosomal regions contained a huge number of genes which make difficulties while determining the genes which contribute to alcoholism risk.
Attempts were made to research the genes which contribute to alcohol risk. 0The study of children of fathers who are alcohol addicted has developed into a long genetic study putting an emphasis on the understanding of factors which contribute to the alcohol use initiation and the risk for alcohol dependence.
Studies which were carried out on many populations demonstrated that coding variations inherent in two genes which affect alcohol metabolism have a very strong effect of protection lowering the risk for alcohol addiction. They affect ADH1B gene and ALDH2 gene which encodes a variant of ADH and ALDH respectively.
With the development of science, it has become possible genotype even a million SNPs with the help of an approach which called studies genomewide association studies (GWASs). Being based on the assumption that variation of common genetics contributes to disease risk, the approach gives the opportunity to get a comprehensive test of association across the genome.
Since the very beginning of alcohol research, animals have been used to carry out experiments and the use of animal models provides researchers with the information about biological effects and individual dependence. Animal models allow to control environmental influences and make it possible to identify factors of genetic risk.
The major focus of NIAAA efforts of sponsored research was the high and low drinking selected lines. These studies have greatly contributed to the understanding of the effects of neurobiological bases for alcohol’s myriad effects.Animal models enable to gain understanding of highly complex mechanisms which underline effect of alcohol diverse and understanding individual differences. Models of animals were also used to identify variations of specific genes which are associated with higher sensitivity to the effect of alcohol. Being commenced in 1990s, the studies used methods which are similar to human studies. They aim to identify quantitative trait loci (QTLs). QTLs are considered to be DNA regions which are associated with a variable in the degree characteristics.
As a rule multiple genes and any QTL gene may have one or several of these genes. Studies carried out on mice and rats, in comparison with humans, show the advantage of the usage of individuals who control mating patterns and make it easier to localize the chromosome region of interest.
Classical QTL gives the opportunity to associate individual differences in the sequence of genes which have the phenomenon differences. The development of transgenic animals which was carried out in 1980s enhanced genetic animal models possibilities. Animals have been genetically modified and a single candidate gene expression was inactivated or augmented if compared with the strain of a parent. The mentioned approach makes it possible to study the influence of genes on the risk of alcohol addiction, as well as possibility of various diseases and behaviors.
Thus, the studies have shown that the risk for alcohol dependence is influenced by genetic and environmental factors and the interplay between them is critical for the determination of alcohol abuse risk and addiction. Development of genetic technologies makes it possible to explore the genome in details. But there is still a challenge how to define the environment such as a family, society, stress, and others. As gene-environment interactions are important from the exposure of adolescents to alcohol consumption, it makes the analysis more complicated.
I would say that some points of the article are controversial ones or I just hardly agree with them. The authors strongly emphasize the fact that genes play a major role in the risk for alcohol dependence. I am strongly convinced that the environment is the key factor and the cause of the addiction. I am also against scientific experiments on animals and do not think that animals are the only way to study the genes as in the case of alcohol dependence it is quite possible to trace people’s genes.
Among the most recent and widely used drugs one should mention Cannabis (contains marijuana), Solvents (inhaling substances as nail polish remover, glue, paint, lighter fuel, etc.), 4-MTA (derives from amphetamine with similar effects to ecstasy), Methylphenidate (stimulant of central nervous system), Anabolic steroids, GHB (Gamma hydroxybutyrate – depressant of central nervous system), Alkyl nitrates (commonly referred to as poppers), Khat (an amphetamine-like stimulant), and others. Most of the drugs are psychoactive (cannabis, ecstasy, heroin, etc.) and they have the ability to affect your mood arousing certain emotions or dampening down others. The result of the drug use is changes in the mood or behavior which happens because changes in the brain. Drugs have an ability to interfere with the brain chemicals. Drugs have short-term effects (anxiety disorder, mood disorder, anxiety) and long-term effects (depressions and schizophrenia) on the mental health.
Cocaine, amphetamine and other drug use lead to psychosis and schizophrenia. The researches show direct link between schizophrenia and cannabis use. If a person has a pre-exiting risk and uses cannabis, the chances that the drug use will trigger schizophrenia are very great. Young people who use cannabis are apt to this disease as well.