Sep 19, 2018
Can Genetics Contribute to Substance Addiction?
Addiction is called a “family disease” because it not only affects the whole family when a member has a substance use disorder but also because there’s a hereditary link that can be passed down. An important aspect of understanding addiction as a disease is seeing how biological and environmental factors can impact addiction. Those who have a family history of addiction should pay particularly close attention to potential risks that may cause them to be more susceptible to substance use disorders. Using science-backed information can help get rid of the stigma surrounding addiction and encourage those who need help to seek it out without feeling ashamed or afraid. Genetics and Addiction Genes are units of DNA that make up the entire human body and DNA provides people with information about what the cells in our bodies are doing. Everyone has a unique set of DNA, which is inherited from their parents giving them traits like hair and eye color, height, and not-so-visible things like risk or protections from diseases like diabetes, auto-immune disorders, and more. Scientists have found that when gene mutations occur, it can pose a potential risk of health problems in the future. One of the diseases that have been extensively studied by researchers is addiction. It’s a complex disease and, genetically speaking, can impact different people in different ways. However, people who have addiction in their family history are not destined to have substance use disorders. Their fate is not sealed in their genetic disposition. Studies are being conducted to find new treatment approaches using new and emerging information that is being discovered while unraveling and studying where addiction fits within the human genome. The human genome is the full set of chromosomes in the human body which include all the inheritable traits of an organism. There will never be just one isolated addiction gene that is passed down from parents to offspring. Instead, addiction should be seen and treated as a vulnerability of complex traits. There are arrays of genes that make up the proneness to addiction, and not everyone with a substance use disorder will have the same variations of genes that carry an addiction risk. Some may end up with this gene arrangement and show no signs of being prone to addiction. Regardless of how complicated the concept of addiction and genetics may be, thorough research has determined there is a link and that addiction is influenced by genes. Family History Another reason why stigma surrounding addiction is so dangerous is the fact that many people never talk about substance use disorders in the family due to shame or fear. Most everyone would want to know if their parents, grandparents, or great-grandparents had a specific disease. In fact, when at the doctor, most people are asked to disclose any family history of illness. Considering addiction is a disease, it’s irresponsible to not disclose these health issues with family. Unfortunately, many people are never made aware that someone in their lineage actually has issues with addiction because they are often kept secret of swept under the rug. Children of people with substance use disorders are eight times more likely to develop an addiction.However, genetics only account for about 50% of the probability that the offspring of someone with a substance use disorder will develop an addiction. The other factors that can impact children of people with substance use disorders are also environmental. Poor coping skills can lead people to self-medicate with substances. Poor mental health care is also a major factor that can lead to drug misuse and potential addiction. Something parents can do for their children to prevent the “addiction gene” from negatively impacting them is helping them learn to deal with stress, emotions, and hard times. Teaching them to ask for and seek help instead of adapting self-destructive habits is crucial in early development. When a child is exposed to parents who misuse drugs or exhibit poor coping skills, they are more likely to learn and mimic this behavior. Once substance use disorders are taken more seriously, and addiction is seen as a disease, families will be better equipped to deal with family members who need help in the future. Adhering to outdated belief systems that view addiction as a character flaw or a problem of the weak-willed will only continue to allow the addiction epidemic to spread. Children deserve transparency from their parents about potential genetic predispositions to addiction they may have so they can be more aware of it as they grow into adults. Prevention Since addiction may present itself in someone with a combination of genetic and environmental factors combined, it’s best to take preventative precautions early on. Raising children in stable, drug-free environments where they are not exposed to substance misuse or very stressful situations is the ideal way to protect them. The reality is, not every child will have this kind of environment growing up, and they may have a parent or a family member who struggles with addiction. Since addiction can affect the family as a whole, these children are more at risk. There is hope, however, for these children and their parents as well. Along with treatment, scientists and genetic researchers are looking to develop improved ways to help people who are impacted by addiction. Each “addiction gene” they can identify becomes a “drug target” that researchers focus on to develop a medicine that can counteract or modify its activity. This will be an advanced way to help stabilize and improve proper brain function in those who are at a particularly high risk both genetically and environmentally. The future of treatment will be enhanced with further genetic research. Soon, people with addiction will be able to be tested to see which medications may be best for their treatment. This is why understanding the role of genetics in addiction is so important. While addiction is a very complex and complicated disease, science and research will be able to help us understand how to handle substance use disorders and treat them more effectively. Sources:https://c0.piktochart.com/v2/uploads/9774d4fb-f157-48bf-aa49-958416867f03/b67baee5b1527f89c55c11e1f463244e7b4e2902_original.jpghttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2715956/https://www.drugabuse.gov/publications/drugfacts/genetics-epigenetics-addictionhttps://pubs.niaaa.nih.gov/publications/arh312/111-118.pdf Medmark treatment Centers _________________________________________________________________________
by Viatcheslav Wlassoff, PhD | August 22, 2018
Addictive behavior is a major global health concern. Addiction is commonly defined as the repetitive use of substances or a repetitive pattern of behaviors that are harmful. It is believed that addiction is a brain disorder, meaning that it is caused by the impact of drugs or other addictive substances/influences on the brain and it can be modified by different environmental factors. The presence of specific variants of some genes may promote or decrease the chances of developing an addiction. According to scientists, genetic factors may play an important role in determining both the vulnerability to addiction and the response to treatments aimed to cure addiction.
The Brain and Genetics in Addictive Behavior
One group of researchers demonstrated that polymorphisms in the genes encoding for opioid receptors and opioid ligands, and more specifically the MOPR gene (OPRM1), is associated with drug addiction. It has been found that one variant of this gene contributes to alcoholism and heroin addiction. Another study has found that carriers of the same gene variant experience a more pronounced sensitivity to pain and decreased analgesic response to opioids, which means that they require higher doses of morphine in the management of pain, such as pain associated with cancer.
Heroin and Opioids
Some authors underlined that addiction to MOPR agonists, including heroin, has become epidemic in the 21st century. According to the same authors, the endogenous opioid system interacts with other neurotransmitter systems in the brain. More precisely, opioid receptors regulate the release of dopamine and serotonin, neurotransmitters with important roles in mood. Additionally, the opioid system seems to interact with noradrenergic, GABAergic, and glutamatergic pathways, as well as with neural growth factors. Furthermore, these studies indicate that chronic exposure to opiates alters gene expression in the brain, and this causes long-term changes in neuronal networks. Activation of opioid receptors leads to changes in the expression of genes in the above-mentioned neurotransmitter pathways. Variations in the genes of those pathways may determine whether someone is more prone to the development of opiate addiction.
One very recent study published this year revealed that the use of cocaine and cocaine addiction are associated with certain variants of the glucocorticoid receptor gene, along with lower expression of this gene. More specifically, the authors of the study compared the expression level of this gene in chronic cocaine users and healthy controls. Apart from significantly lower gene expression in the cocaine users, the carriers of some gene variants were at increased risk of cocaine addiction. In addition, they scored higher on depression scales.
It seems that the major challenge in understanding and treating addictive disorders is understanding why some individuals develop addiction while others do not. According to research findings, whether or not a person will become addicted depends largely on genetic factors, which contribute ~50% of the risk for addiction. The processes in our brain are also important. It is well established that the rewarding effects of drugs and addictive substances, in general, are based on their ability to increase the level of dopamine in the brain. Accordingly, imaging studies have shown that individual variations in brain circuits modulated by dopamine, including circuits involved in the mechanisms of reward, contribute to the inter-individual variability in the vulnerability to addiction. Thus, it seems that the roles of genetic factors and brain pathways in the addiction may be intertwined via dopamine.
Alcohol and tobacco
Apart from drug addiction, addiction to alcohol seems to depend on genetics and is influenced by heritage. A recent study has investigated the effects of parental drinking on the use of alcohol in young adults. More than 3500 adolescents and their parents have been included in this prospective research. As results have indicated, young adults whose parents are moderate or high alcohol consumers are more prone to alcohol consumption than those young adults whose parents don’t consume alcohol or consume it in low quantities. Alcohol and tobacco use represent leading global health risks, which are responsible for 3.3 and 6 million premature deaths per year respectively, according to the World Health Organization. Genetic factors were estimated to contribute 40-60% and 40-85% to the development of alcohol and tobacco addictions respectively. Finding out which genetic variants are associated with alcohol and tobacco addictions would be an important step in understanding their underlying mechanisms and developing the effective therapies. Over the last years, Genome-Wide Association Studies (GWAS) have been performed in order to elucidate the role of certain genes and their variants in alcohol and tobacco use. These studies have recognized that single nucleotide polymorphisms (SNP, i.e., gene variants with a difference in a single nucleotide) are important for developing these addictions. For alcohol addiction, SNPs include polymorphisms in the KLB gene, as well as in the alcohol dehydrogenase gene cluster. In the latter, different variations of genes differently influence the metabolism of alcohol. In the case of tobacco use, the most evident variations have been detected in the nicotinic acetylcholine receptor subunit genes cluster. However, only a small number of common genetic variants have been studied, and they account for a modest proportion of alcohol and nicotine addiction heritability. Thus, further investigation into the role of low frequency and rare genetic variants is required in order to fully understand the heritability of both alcohol and tobacco use.
Considering all of these facts together, it seems that genetics does indeed play an important role in the development of addiction to substances such as opioids, alcohol, and tobacco. Some of these factors include differences in gene expression and gene variants in brain neurotransmitter pathways. Further research is needed in order to develop working strategies for treating heritable addictions. References Kreek, M.J., Levran, O., Reed, B., Schlussman, S.D., Zhou, Y., Butelman, E.R. (2012). Opiate addiction and cocaine addiction: underlying molecular neurobiology and genetics. Journal of Clinical Investigation. 122(10): 3387-3393. DOI: 10.1172/JCI60390 Shi, Q., Cleeland, C.S., Klepstad, P., Miaskowski, C., Pedersen, N.L. (2010). Biological pathways and genetic variables involved in pain. Quality of Life Research. 19(10): 1407–1417. doi: 10.1007/s11136-010-9738-x Reed, B., Butelman, E.R., Yuferov, V., Randesi, M., Kreek, M.J. (2014). Genetics of opiate addiction. Current Psychiatry Reports. 16(11): 504. doi: 10.1007/s11920-014-0504-6 Schote, A.B., Jäger, K., Kroll, S.L., et al. (2018). Glucocorticoid receptor gene variants and lower expression of NR3C1 are associated with cocaine use. Addiction Biology. doi: 10.1111/adb.12632 Volkow, N.D., Wang, G.J., Fowler, J.S., Tomasi. D. (2012). Addiction circuitry in the human brain. Annual Review of Pharmacology and Toxicology. 52: 321-336. DOI: 10.1146/annurev-pharmtox-010611-134625 Mahedy, L., MacArthur, G.J., Hammerton, G., et al. (2018). The effect of parental drinking on alcohol use in young adults: the mediating role of parental monitoring and peer deviance. Addiction. doi: 10.1111/add.14280 Marees, A.T., Hammerschlag, A.R., Bastarache, L., et al. (2018). Exploring the role of low-frequency and rare exonic variants in alcohol and tobacco use. Drug and Alcohol Dependence. 188: 94-101. doi: 10.1016/j.drugalcdep.2018.03.026