Genetics and Opioid Addiction: California Drug Rehab Looks at the Connection

The Connection Between Genetics and Opioid Addiction

This entry was posted on by .

Addiction is not a moral failing; it’s a disease, and for some, it’s a genetic trait. Ocean Hills Recovery, California drug rehab, explores the connection between genetics and opioid addiction. Understanding this link can help individuals struggling with opioid addiction understand why it’s important to reach out for help.

Research Indicates a Connection Between Opioid Addiction and Genetic Factors

Opioids can produce pain relief or euphoric feelings. This is due to the chemical interaction that takes place when opioid drugs latch onto opioid receptors located throughout the body. People who misuse opioids or take them for an extended period of time risk becoming dependent on them or even addicted. For years, researchers have tried to determine why some are more susceptible to opioid addiction than others.

Several studies support the theory that variations in the genes found in opioid and dopamine receptors may connect genetics and opioid addiction. Ocean Hills Recovery, a California drug rehab facility, summarizes some of the most significant research reported to date.

Family and Twin Studies

For years, scientists have attempted to discover how genetics and environmental factors contribute to drug and alcohol addiction. By studying separated twins or adoptees (raised by non-biological parents), they’ve been able to establish that genes play a role in whether or not a person is likely to become dependent on or addicted to illicit substances.

One large twin study from 1998 examined 3,372 pairs of male twins to discover how genetic and environmental factors contribute to the co-occurrence of abuse for various illicit substances. These included heroin or opiates, marijuana, psychedelics, sedatives, and stimulants. Except for psychedelics, results showed that each type of drug had unique genetic influences. Heroin and opiates, however, showed more unique genetic effects than any of the other drugs. [1]

Another study aimed to determine whether genetics was a strong determinant of drug abuse in relatives of those with a substance use disorder. Results indicated that subjects who abused cocaine, marijuana, and opioids were likely to have relatives addicted to the same substance. But someone related to a person with an opioid use disorder was ten times more likely to be similarly afflicted, whereas the odds for cocaine and cannabis were much lower. [2]

Studies on Genetics and Opioid Addiction

Researchers have also zeroed in on particular genes that may have a high likelihood of predicting opioid use disorder. Both opioid receptor genes and dopamine receptor genes have been widely studied:

DRD2 gene

Variations in the dopamine receptor gene have been associated with the increased use of heroin and a greater vulnerability to addiction. A study followed opioid-dependent patients for over a year and found a particular allele (gene variant) in 19% of the patients. This is compared to only 4.6% of control group subjects with no personal or family history of drug or alcohol abuse. [3]

DRD4 gene

One of the first reports of the association of gene variation and opioid addiction came from examining the DRD4 dopamine receptor gene. In this experiment, the researchers – who had previously established a connection between novelty seeking and a particular variation of the DRD4 gene – wanted to determine if opioid-addicted individuals were more likely to show the gene variation. Results showed that 29.1% of the opioid-addicted subjects had the gene variation, while only 11.8% of the control group did. [4]

OPRM1 gene

This gene operates the mu-opioid receptor, the first opioid receptor discovered by the scientific community. It is the primary location for the most opioid-binding activity. The OPRM1 variant known as A1118G (rs1799971) is widely believed to be associated with opioid dependence. It also appears to impact some ethnic populations more than others. [5]

Scientists continue to study genes to determine how they might be altered or edited to improve opioid use disorder treatment. Recently, researchers mutated more than 900 genes in a class of worms. They discovered that some modifications impacted how these worms responded to morphine. They repeated the study with mice and saw that the mice lost interest in morphine when the gene was altered. This indicates that the specific gene variation could control the opioid signaling mechanism and could prevent addiction to opioids. [6]

Continued after infographic:

Genetics and Opioid Addiction: California Drug Rehab Looks at the Connection INFOGRAPHIC

California Drug Rehab Helps with Genetics and Opioid Addiction

There is strong evidence to conclude that genes may influence whether or not someone becomes addicted to opioids. However, it’s important to remember that other factors (social, economic, lifestyle) also predict the likelihood of developing an opioid use disorder. Just as the reasons for becoming addicted to opioids are varied, so are the individuals who need treatment. That’s why Ocean Hills Recovery customizes its drug rehab programs for each patient who enters our doors. This approach has helped countless patients to navigate their recovery once they complete their program successfully.

Ocean Hills Recovery offers a nurturing and supportive environment. We gently guide our clients to help them learn and practice skills they’ll need in recovery. If you or a loved one is battling an addiction to opioids, contact one of our caring staff members for more information about our programs.



[4] Kotler, M., Cohen, H., Segman, R. et al. Excess dopamine D4 receptor (D4DR) exon III seven repeat allele in opioid-dependent subjects. Mol Psychiatry 2, 251–254 (1997).,

About the author: