TUESDAY, Dec. 10, 2024 (HealthDay News) -- “This is your brain on drugs,” the old anti-drug admonition says, and now a new study has found there’s something to that chestnut.

Opioid addicts experienced structural and functional changes in specific regions of their brains, MRI scans show.

These changes are important to understand, given that around 2.5 million adults in the U.S. have opioid use disorder, researchers said. There were more than 81,000 overdose deaths involving opioids in 2023.

“Our goal is to understand better what could have caused these alterations to inform new treatment targets,” said researcher Dr. Saloni Mehta, a postdoctoral associate with the Yale School of Medicine’s Department of Radiology and Biomedical Imaging.

For the study, published Dec. 10 in the journal Radiology, researchers compared brain scans of people addicted to opioids with those of non-addicts, using scans performed between February 2021 and May 2023.

Specifically, researchers looked at structural MRI scans for 103 people with opioid addiction and 105 non-addicts, and functional MRI scans for 74 addicts and 100 controls.

Functional MRI scans can measure brain activity by detecting changes in blood flow, while structural scans take snapshots of the shape of different brain regions.

The scans showed changes in brain regions that contain large amounts of opioid receptors, researchers said.

Some regions like the thalamus and the right medial temporal lobe of the brain were smaller in opioid addicts, while others like the cerebellum and brainstem were larger.

These brain regions also appeared to have increased functional connectivity between them, researchers said.

The results also showed some differences between men and women when it came to brain changes linked to opioid addiction.

“Previous studies have been performed on small sample sizes, many of which included no women,” Mehta explained in a journal news release. “Ours is a moderate sample size, approximately half of which is female.”

“We found that alteration patterns in the medial prefrontal cortex -- a core region involved in many mental health conditions -- were different between men and women in the group with opioid use disorder,” Mehta added. “This highlights the importance of assessing sex differences in opioid use disorder neuro-imaging studies.”

Now that these differences have been found, researchers will investigate what they mean and how they might influence a person’s behavior, Mehta said.

Future research also needs to figure out whether these brain changes are permanent, or if they subside after a person receives treatment for their addiction, he added.

“Our eventual goal is to examine how brain alterations in individuals with opioid use disorder may be linked to outcome measures,” Mehta said.

More information

The U.S. Centers for Disease Control and Prevention has more on opioid use disorder.

SOURCE: Radiological Society of North America, news release, Dec. 10, 2024