Binge drinking can trigger genetic changes that make people crave alcohol even more, researchers from Rutgers University have found. It’s the latest in a growing body of evidence that alcohol and drug use causes genetic changes that may reinforce addiction and can be passed down to future generations.

The study found that genes involved in controlling drinking behavior act differently in heavy drinkers. PER2, which influences the body’s biological clock, and POMC, which regulates the stress response system, show reduced gene expression, meaning they produce proteins at a lower rate than normal. Those people have a greater desire for alcohol, and often drink more.

“It’s an egg-and-chicken kind of thing,” said Dipak Sarkar, co-author of the study and director of the endocrine program at Rutgers. “You drink and you want to stop, but stopping gets harder because you have an alteration of your gene that makes you more susceptible to drink.”

The findings bolster the idea that the genetic implications of using drugs and alcohol are much broader than during conception or pregnancy. Drinking or drug use even in adolescence can create lasting genetic change that will affect future children, researchers say.

“It’s pretty amazing that stressors like drugs can create genetic change,” said Bill Jangro, medical director for the division of substance-abuse programs at Thomas Jefferson Hospital in Philadelphia. “It goes against what most people think.”

Even a substance like alcohol, which many think of as lower risk, has this effect. Most research in this area focuses on alcohol’s ability to change DNA, though studies show a similar effect from opioids, cocaine, cannabis and methamphetamine.

Researchers in the field of epigenetics, which studies how the environment can affect the way a person’s genes are expressed, are hunting for answers. The answers, they say, could change the way we think about addiction, and even suggest ways to treat substance use disorders at a genetic level.

The basic idea of genetic change centers on evolution: Genes that favor survival continue to be passed on while others die out. The process can take hundreds of thousands of years.

Epigenetics focuses instead on how environmental factors can cause more immediate change, within an individual’s lifetime and passed down to the next generation.

In the Rutgers study, researchers found the more someone drank, the more genetic change they exhibited. The alcohol influenced a process called methylation.

Methylation keeps a DNA sequence intact but uses a chemical tag to turn certain genes on or off. It’s one of the key ways environmental stressors — from alcohol and drugs to physical and emotional stress on the body — can cause genetic change.

Today, observing certain types of DNA methylation can tell us if someone has used drugs — a technique applied in forensic sciences.

Although it has long been observed that addiction can “run in families,” DNA analysis doesn’t tell us if someone is more likely to use drugs in the future. That’s the holy grail researchers are searching for, Sarkar said: a biomarker.

If certain changes in DNA methylation predispose someone to addiction, we could identify those individuals and create early interventions, Sarkar said. “Even limited exposure to opioids can have lasting effects across multiple generations,” the authors said.