Inherited Traits, Genetics, & Epigenetics of Substance Abuse

Inheritance Traits Definition

An inherited trait is one that is genetically determined. Inherited traits are passed from parent to offspring according to the rules of Mendelian genetics. Most traits are not strictly determined by genes, but rather are influenced by both genes and the environment. The common inherited traits examples are tongue rolling, earlobe attachment, curly hair, freckles, handedness, hairline shape, and green/red colorblindness.

What Are Inherited Traits?

Genetics is the study of genes. Genes are functional units of DNA that make up the human genome. They provide the information that directs a body’s basic cellular activities. Research on the human genome has shown that, on average, the DNA sequences of any two people are 99.9 percent the same. However, that 0.1 percent variation is profoundly important—it accounts for three million differences in the nearly three billion base pairs of DNA sequence! These differences contribute to visible variations, like height and hair color, and invisible traits, such as the increased risk for or protection from certain diseases such as heart attack, stroke, diabetes, and drug addiction. [1]

In individuals who are vulnerable to addiction, repetitive exposure to the agent induces long-lasting neuroadaptive changes that further promote drug-seeking behavior and ultimately lead to persistent and uncontrolled patterns of use that constitute addiction. These neuroadaptive changes are the basis for tolerance, craving, and withdrawal and lead to a motivational shift. Motivation to drug-seeking behavior is initially driven by impulsivity and positive reward. In contrast, compulsivity and negative effect dominate the terminal stages of the pathology. Addictions are in a sense “end-stage” diagnoses because at the time diagnosis is made potentially irreversible neuroadaptive changes have occurred—changes that were preventable at an early point of the trajectory of the illness.

The use and abuse of legal and illegal psychoactive substances is a worldwide public health priority with repercussions on individuals, their families, and society. According to the World Health Organization (WHO), alcohol subtracts 69.4 million of disability-adjusted life years (DALYs); tobacco, 59.1 million; and illicit drugs, 12.2 million. From an economic perspective, the cost of substance use and SUDs in the United States is approximately $484 billion/year, which is comparable to the cost of diabetes ($131.7 billion/year) and cancer ($171.6 billion/year). [3]

What Controls Traits And Inheritance

Accumulating evidence suggests that environmental factors, such as stress, induce epigenetic changes that can trigger the development of psychiatric disorders and drug addiction. Epigenetic changes refer to regulations of gene expression that do not involve alterations in the sequence of the genetic material (DNA) itself. Practically, epigenetic changes are information that is added to already existing genetic material but can affect the expression of genes.

A stressful situation, such as the death of a significant other or the loss of a job, triggers the release of steroid hormones called glucocorticoids. Those stress hormones trigger alterations in many systems throughout the body, induce epigenetic changes, and regulate the expression of other genes in the brain. One of the systems that are affected by stress hormones is the brain’s reward circuitry. The interaction between stress hormones and the reward system can trigger the development of addiction, as well as a stress-induced relapse in drug or alcohol recovery. [4]

Is Addiction An Inherited Trait

Why do some people become addicted while others don’t? Family studies that include identical twins, fraternal twins, adoptees, and siblings suggest that as much as half of a person’s risk of becoming addicted to nicotine, alcohol, or other drugs depends on his or her genetic makeup or inherited traits. Finding the biological basis for this risk is an important avenue of research for scientists trying to solve the problem of drug addiction. 

The risk of developing drug and alcohol problems is higher in children whose parents abuse alcohol or drugs—but it is NOT a guarantee. Research shows that children with parents who abuse alcohol or drugs are more likely to try alcohol or drugs and develop alcoholism or drug addiction. Why?

Of course, most children of parents who abuse alcohol or drugs do not develop alcoholism or addiction themselves, so your genes do not write your destiny to become addicted to drugs. BUT to avoid that risk entirely, it’s best not to start, and if you’ve already tried drugs or alcohol, stop now. [5]

Addiction Treatment And The Help Of Genetics

It is not surprising that the genes discovered so far act in a variety of ways: via altered metabolism of the drug (the alcohol and nicotine metabolic gene variants), through the altered function of a drug-receptor (the nicotinic receptor, which may alter affinity for nicotine but as discussed may also alter circuitry of reward), and via general mechanisms of addiction (genes such as monoamine oxidase A and the serotonin transporter that modulate stress response, emotion, and behavioral control). Addiction medication today benefits from genetic studies that buttress the case for a neurobiological origin of addictive behavior, and some general information on familially transmitted propensity that can be used to guide prevention.

Clinicians often find substantial variability in how individual patients respond to treatment. Part of that variability is due to genetics. Genes influence the numbers and types of receptors in peoples’ brains, how quickly their bodies metabolize drugs, and how well they respond to different medications. Learning more about the genetic, epigenetic, and neurobiological bases of addiction will eventually advance the science of addiction. 

When someone has a drug problem, it’s not always easy to know what to do. Drug addiction is a complex issue that requires long-term treatment – not a quick fix. Therefore, the first step in drug abuse treatment is to seek help from your medical provider or a trained professional.

As the addiction treatment community begins to realize that addiction is itself a mental disorder, the relationship between substance abuse and inherited traits such as mental disorders becomes more complicated. The greater treatment community largely lacks a proper understanding of dually diagnosed conditions, so these conditions are still treated separately, or worse–not treated or diagnosed at all. Dual diagnosis treatment centers in We Level Up Florida, California, Texas, New Jersey are some of the facilities that have professionals trained to help treat co-occurring disorders concurrently. This type of tandem treatment provides some of the best success rates. 

Get substance abuse treatment for individuals struggling with addiction. Call us today!