The scientists met at the Stritch School of Medicine to talk about the negative side effects that the consumption of alcohol can produce on how our genes function and how all of these changes are passed down from generation to generation through our cells. These specific modifications do not include changes in our DNA patterns but rather are recognized as epigenetic changes which are caused by the consumption of alcohol.

The scientists’ discussion focused on these epigenetic changes and specifically the two key events that manifest in our genes known as DNA methylation and DNA histone deacetylation. The Director of Loyola’s Alcohol Research Program, Dr. Elizabeth J. Kovacs, says epigenetic is one of many new frontiers in the research of alcohol consumption. Kovacs points out that nearly 50 faculty members at Loyola are involved in this type of research and the group includes faculty members, postdoctoral fellows, students and technicians who are eager to explore these new findings.

The conference was sponsored by several alcohol research interest groups, including Loyola’s own Alcohol Research Program and their Dept. of Surgery and also the National Institute on Alcohol Abuse and Alcoholism and the society for Leukocyte Biology.

Dr. Linden, writing in The New York Times, said that addicts are risk-takers and novelty-seekers. They are people whose brains are wired in such a way that they actually feel less pleasure from food, drugs, gambling and other addictive activities and substances than do ordinary people. They are obsessive about seeking these things out. This obsessive part of their personality mixed with their risk-taking ability and creativity can give them star quality at work.

Some famous people Dr. Linden has studied who abused substances were Aldous Huxley, Alexander the Great, Winston Churchill, Charles Baudelaire, Sigmund Freund, and Otto Von Bismarck.

In an article published in Archives of General Psychiatry, researchers emphasized again what many addiction specialists have known for years: a person’s chances of becoming an alcoholic are closely influenced by their genetics and the type of home environment they are exposed to. Even if one parent suffers from alcoholism, a child still has a risk up to four times higher of being diagnosed as an alcoholic in adulthood.

Each family reacts to alcoholism differently, adding to the complexity of the disease. In many cases, a spouse will demonstrate protective or avoidance behaviors as a measure of protection. At the same time, these actions from the spouse set up an environment where the alcoholism continues to remain untreated.

For children who grow up in this household, several long-term consequences are noted. Some may end up with spouses who are alcoholics – an effort to recreate a home environment to which they are comfortable, even if it is painful. If they become alcoholics as adults, these children are also likely to perpetuate the family cycle, and are more likely to see their own children suffer from alcoholism.

Stopping family cycles of alcohol addiction can be done, say experts, but it is a very challenging process involving serious change, such as a spouse leaving the spouse who suffers from alcohol addiction. Members of the family from outside this immediate unit may shun the spouse for leaving, or in other cases, ignore their requests for help in order to try to maintain a sense of family balance.

As families suffer from generation to generation with alcoholism, psychologists note that children do not learn adequate ways of handling or coping with stress in their lives. In some studies, males whose fathers are alcoholics show repeated visits to physicians and more instances of depression or anxiety than boys whose fathers do not abuse alcohol. Daughters whose parents are alcoholics may show higher incidences of eating disorders and also more physical health problems as adults.

According to the American Academy of Child and Adolescent psychiatry, 20 percent – or one out of five- adults in the U.S. shared their household with someone addicted to alcohol during their childhood. The study of alcoholism as a family disease is prompting more research into intervention toward the lifelong emotional effects of alcoholism, as well as ways to use genetic technology to locate the genes responsible for the likelihood toward alcohol addiction.

If successful, this type of research could open doors toward new ways to both treat people and help prevent alcoholism in families before it occurs – advancements that could occur alongside treatments like counseling and family-centered strategies.

There’s no use going into rehab because it’s genetic.

I read that 60% of the people with genes like mine are drug addicts.

Science says that drug addiction is a hereditary brain disease so you’re stuck with it forever.

Many people addicted to drugs (or who love someone who is) become troubled when they think about the influence of genetics on substance abuse. The latest research about the human genome makes them feel doomed to lives they don’t want for themselves or their children.

However, if you think this way, it means you don’t get the full picture. The truth is that although the amount of research in this field is exploding, we still do not understand completely how genetics influences substance abuse.

We do know that you do not inherit substance abuse, you inherit a susceptibility to it. There is a big difference between the two. Even if you carry the genes for it, you cannot become a drug addict in an environment where drugs are not available. For example, the daughter of Amish farmers may never be exposed to drugs and still carry the genotypes. The son of middle-class suburbanites with similar genes may never touch drugs unless he enters a drug-friendly environment, such as a college campus or military base. In environments where peers and attitudes are drug-tolerant, he could quickly develop a problem when he experiments with drugs.

This means that genetics and environments can cancel each other out when it comes to drug addiction. People with a genetic susceptibility to drug abuse can never develop a problem, and people without the gene can literally "rewire" their brains by abusing drugs excessively. Some studies on laboratory animals indicate that certain drugs, particularly cocaine, can alter genetics so that future offspring will carry genotypes for drug susceptibility.

Scientists know more about the influence of genetics on alcoholism compared to what they know about its influence on substance abuse. For one thing, it is hard for them to study the two separately because one-half the people who use drugs also abuse alcohol. However, many experts believe that common genotypes contribute to both. The new thinking is that there are "gene clusters" that work together to create a susceptibility to substance abuse. These include genes for anxiety and depression disorders, attention deficit/hyperactivity disorder (ADHD), and most frequently, conduct disorder. In one study, 40% of children who experienced depression before they were 14 years old become substance abusers. In a study of 118 identical twins, if a twin had certain personality traits, especially thrill-seeking, he was more likely to use drugs than his twin without the trait.

Males with conduct disorders are at high risk for substance abuse, and children with ADHD are at high risk for developing conduct disorders. This does not mean that ADHD causes drug addiction. What it might imply is that if a male has a gene cluster for ADHD, depression, thrill-seeking, and alcohol abuse, he is more likely to develop substance abuse disorder.

Other factors that are not necessarily genetic also put a person at higher risk for drug abuse. These may be a tolerant attitude toward drugs, bullying or peer rejection in elementary school, problems with legal authorities, academic failure, dysfunctional family, and more. Using smoked or injected drugs is also a risk factor. All these factors complicate the science of genetic influence.

People who start using drugs early, in middle school, for example, are more likely to become addicts. Identical twins separated at birth tell us that environment (including parents) influences the age you start experimenting with substances, but genetics influences how much you use once you start.

Most new research does point to a strong genetic influence on substance abuse disorder. Scientists can breed animals with drug-seeking behaviors, for example. Adopted children tend to be more similar to their biological parents, not their adoptive ones, when it comes to drug abuse. Genetics plays a strong role in your first reactions to drugs or alcohol. Some people will get nausea from just one drink, for example. Others need three or four drinks just to get a "buzz," and these differences are about genetics and the way you metabolize alcohol.

Certain studies of identical twins brought up in different environments found 66% inheritability factor for alcoholism and 33% for drugs. Some people interpret this as meaning if you have certain genes, you have a 66% chance for developing alcoholism, but this is not the case.

A scientist may have a sample of 10,000 people, and 500 of them are substance abusers. Of this group, there are nine sets of identical twins or 18 people. In six sets of these twins, both are alcoholics, but there are three sets of twins where one is alcoholic and one isn’t. This is where our scientist gets the 66% inheritability figure. The inheritability for blue eyes is 100%, meaning all twins have the same eye color. The inheritability for substance abuse is 32%. But you have to remember that our scientist has thrown out 9,500 people who are not substance abusers, and some of whom may carry the gene for susceptibility to drug abuse. So the 33% inheritability for drug abuse is only among the population of drug abusers.

Genetics no doubt plays a strong role in determining who becomes a substance abuser. If you carry these genotypes, it means you may have to be careful in how you approach recreational and pharmaceutical chemicals in our society. By no means does it condemn you to a life of addiction.

References

Agrawal, Arpana; Lynskey, Michael T. Are there genetic influences on addiction: evidence from family, adoption and twin studies. Addiction; Jul2008, Vol. 103 Issue 7, p1069-1081, 13p.

Ball, David. Addiction science and its genetics. Mar2008, Vol. 103 Issue 3, p360-367.

Button, Tanya; Rhee, M.M.; Hyun, Soo; Hewitt, John; Young, Susan; Corley, Robin; Stallings, Michael C. The role of conduct disorder in explaining the comorbidity between alcohol and illicit drug dependence in adolescence. Drug & Alcohol Dependence; Feb2007, Vol. 87 Issue 1, p46-53.

Derringer, Jaime; Krueger, Robert F.; McGue, Matt; Iacono, William G. Genetic and environmental contributions to the diversity of substances used in adolescent twins: a longitudinal study of age and sex effects. Addiction; Oct2008, Vol. 103 Issue 10, p1744-1751.

Dick, Danielle; Agrawal, Arpana. The Genetics of Alcohol and Other Drug Dependence. The National Institute of Health publications, posted at http://pubs.niaaa.nih.gov/publications/arh312/111-118.pdf

Fowler, Tom, Lifford, Kate; Shelton, Katherine; Rice, Frances; Thapar, Anita; Neale, Michael; McBride, Andrew; van den Bree, Marianne B. Exploring the relationship between genetic and environmental influences on initiation and progression of substance use. Addiction; Mar2007, Vol. 102 Issue 3, p413-422.

Kreek, Mary; David A Nielsen, Eduardo R Butelman & K Steven LaForge. Genetic influences on impulsivity, risk taking, stress responsivity and vulnerability to drug abuse and addiction Nature Neuroscience 8, 1450 – 1457 (2005)

Lange, Leslie; Kampov-Polevoy, Alexey; Garbutt, James. Sweet Liking and High Novelty Seeking: Independent Phenotypes Associated with Alcohol-related Problems. Alcohol & Alcoholism; Sep/Oct2010, Vol. 45 Issue 5, p431-436.

Learn About the Genetics of Addiction, The University of Utah Genetic Science Learning Center, http://learn.genetics.utah.edu/content/addiction/genetics/candidate.html

Sihvola, Elina; Rose, Richard J.; Dick, Danielle M.; Pulkkinen, Lea; Marttunen, Mauri;
Kaprio, Jaakko. Early-onset depressive disorders predict the use of addictive substances in adolescence: a prospective study of adolescent Finnish twins. Addiction; Dec2008, Vol. 103 Issue 12, p2045-2053.

Uhl, George; Dragon, Tomas; Johnson, Catherine; Liu, Qing-Rong. Addiction Genetics and Pleiotropic Effects of Common Haplotypes that Make Polygenic Contributions to Vulnerability to Substance Dependence. Journal of Neurogenetics; 2009, Vol. 23 Issue 3, p272-282.
Uhl, George, Gregory I. Elmer, Michele C. LaBuda, and Roy W. Pickens. Human Substance Abuse Vulnerability and Genetic Influences. Psychopharmacology, 2000.
Vink, Jacqueline; Nawijn, Laura; Boomsma, Dorret; Willemsen, Gonneke. Personality differences in monozygotic twins discordant for cannabis use. Addiction; Dec2007, Vol. 102 Issue 12, p1942-1946.

Xian, Hong; Scherrer, Jeffrey; Grant, Julia; Eisen, Seth; True, William; Jacob, Theodore; Bucholz, Kathleen K. Genetic and environmental contributions to nicotine, alcohol and cannabis dependence in male twins. Addiction; Aug2008, Vol. 103 Issue 8, p1391-1398.
 

The first study from the National Institute of Health’s Office of Research on Women’s Health found that young women have a 60% to 70% higher rate of abusing stimulants as well as painkillers containing opium compared to young men their age. Dr. Vivienne Pinn, author of the report, said that females are using stimulants for weight control and to improve academic performance.

Young women abuse drugs more than males their age because of genetic factors, according to research by Professor Judy Silberg of the Virginia Commonwealth University. Her study involved 1070 twin adolescents, ages 12 to 17 years old, found that genetics probably influenced girls, but environmental factors were a greater determinant for boys.

"Risk factors for substance abuse are different in boys and girls," she said. "In girls, there was a significant genetic influence on all substance abuse in adolescence. With boys, environmental factors, including dysfunctional family and peers using drugs and alcohol, had a pervasive influence," said Dr. Silberg.

This study appears in the Journal of Child Psychology and Psychiatry.
 

Such signals can include advertisements, drinks placed on a bar and witnessing the surrounding people consuming alcoholic beverages. Research suggests that an individual’s genetic makeup determines their response to such cues.

For the individual who drinks, alcohol consumption is known to increase levels of dopamine. This brain chemical causes pleasure and makes the individual feel good. DRD4 (dopamine D4 receptor gene) is known to be involved in motivation to seek rewards. Carrying a specific form of DRD4 may be associated with craving caused by alcohol-related cues.

Researchers at the Radboud University in The Netherlands wanted to examine a specific variant of this gene – one that includes seven or more repeats of a certain gene section. The idea was to determine how much of a role this gene plays in alcohol-related cues.

In the process of studying the effects, findings from this study suggest that individuals who carry this specific form of DRD4 have the potential to be more sensitive to the drinking behaviors of others, than non-carriers.

The authors of the reported noted that the 7-repeat of the DRD4 has the potential to increase the risk of extensive alcohol use or abuse when time is spent with peers who also happen to be heavy drinkers.
 

Research has shown that heritable factors are a big part of dependency on alcohol and cannabis, which can influence many other areas of life. However, there has been a lack of research into how heritable influences overlap across the two substances.

A new study seeks to look at the overlap between heritable factors across the two substances and how use might be attributed to environmental or common genetic influences. Sartor, et al., of the Washington University School of Medicine, the Queensland Institute of Medical Research, and the University of the Sunshine Coast studied the relationships between these factors.

The researchers quantified cross-substance overlap in sources of variance and estimated the extent of associations between use and dependence measures and how genetic and environmental factors might be responsible.

To gather their data, the researchers used the Australian Twin Registry. The sample consisted of 2,761 sets of twins and 735 singletons, totaling 6,257 individuals. Telephone interviews were used to gather information about alcohol and cannabis use and history.

Using the data collected via telephone survey, the study employed standard genetic analysis to establish a quadrivariate model that showed estimates of overlap in genetic and environmental factors across the four phenotypes.

The results of the study showed an over 60 percent of variance in alcohol consumption, cannabis use, and cannabis dependence symptoms, and close to a 50 percent of variance in alcohol dependence symptoms were found to be from genetic sources.

The study found that common environmental influences did not contribute to the four phenotypes. The overlap in heritable influences was almost complete for within-substance measures of use and dependence.

The findings of this study indicate that common genetic factors are influential for alcohol and cannabis use and for dependence, but substance-specific influences are largely responsible for the genetic variance in the cannabis use and dependency phenotypes.

In addition, the study has suggested that measures of the frequency and heaviness of use may indicate genetic factors are also responsible for alcohol and cannabis problems, as they are for dependency measures.

In comparing twins and singletons, this study has examined the genetic influences on alcohol and cannabis dependency. The results show that genetics play a big part in determining behaviors related to substance abuse.

Science Daily recently examined the findings of this study, led by Boris Tabakoff, Laura Saba and Paula Hoffman from the University of Colorado, Denver, USA. This team found that the drinking behavior among the rats was linked to the pleasure and reward pathways in the brain and also linked to some of the same genetic systems that are involved in control satiety and appetite for food.

The next step involved comparing the genes related to these alcohol-associated pathways in rats with the human versions of these genes in two male study groups from Montreal and Sydney. The goal was to identify common genetic factors linked to alcohol use across species.

One of the key findings in this study was that the genes identified as contributors to drinking behavior in the tested populations were not the same as those genes found to predispose to alcohol dependence. In other words, the genetics that lead you to drink are not the same ones that can lead to alcoholism.

According to Tabakoff, “We know that high levels of alcohol consumption can increase the risk of becoming alcohol dependent in those who have a genetic make up that predisposes to dependence. This is a case of interaction between genes and environment. Indeed, in our study we found that, higher alcohol consumption in humans was positively correlated with alcohol dependence…individuals with a genetic predisposition to drink high amounts of alcohol may not have the genes that predispose them to become dependent.”

For those who may or may not be at a higher risk for dependence, the message is clear – the amount and frequency of alcohol consumed has more to do with developing dependence.