Researchers identify brain mechanism linking PTSD and opioid addiction

April 23, 2018, University of Western Ontario
Credit: Human Brain Project

Researchers at Western University have shown that the recall of traumatic memories enhances the rewarding effects of morphine, shedding light on the neurobiological link between post-traumatic stress disorder (PTSD) and opioid addiction.

Steven Laviolette, PhD, associate professor at Western's Schulich School of Medicine & Dentistry says the research was aimed at finding the underlying neural mechanism that might help to explain why almost 60 per cent of those who suffer from PTSD, also struggle with addiction issues.

Laviolette and his team demonstrated in a study published online today in JNeurosci that dopamine receptors in the prefrontal cortex of the brain likely play a role because of their involvement in both traumatic recall and addiction vulnerability. The researchers focused on two in the pre-frontal cortex, D1 and D4.

"What we were trying to find is a mechanism to account for why recall of , such as what you see in PTSD, make some more vulnerable to addictive effects of drugs like opioids," said Laviolette.

Using a rodent model, the researchers found that if they stimulated the D4 receptors, it made a normally non-traumatic memory become emotionally salient, or traumatic, which also led to an increased preference for morphine. They also showed that if they blocked the D1 receptor, they blocked the traumatic memory recall and lessened the rewarding effect of the morphine.

Recalling traumatic memories enhances the rewarding effects of morphine in male rats. These findings may help to explain the co-occurrence of post-traumatic stress disorder (PTSD) and addiction. Credit: Li et al., JNeurosci (2018)

The results suggest that abnormal dopamine signals in the may underlie the ability of traumatic memories to predispose individuals to addiction by increasing their sensitivity to the rewarding effects of drugs such as opioids.

"The main finding is that the D1 and D4 receptors independently control both the impact of traumatic memory recall and how that modulates the increased vulnerability to opioid addiction," said Laviolette. "So even if they've gone through the , if you can block the recall, you can simultaneously block the increased addiction vulnerability."

The researchers hope that this might provide new hope to PTSD patients by providing a clinical target that would help to not only repress traumatic memories, but also concurrently remove their vulnerability to .

Explore further: Research identifies a way to block memories associated with PTSD or drug addiction

More information: Fear Memory Recall Potentiates Opiate Reward Sensitivity through Dissociable Dopamine D1 vs. D4 Receptor-Dependent Memory Mechanisms in the Prefrontal Cortex, JNeurosci (2018). doi.org/10.1523/JNEUROSCI.3113-17.2018

Related Stories

Research identifies a way to block memories associated with PTSD or drug addiction

December 5, 2012
New research from Western University could lead to better treatments for Post-Traumatic Stress Disorder (PTSD) and drug addiction by effectively blocking memories. The research performed by Nicole Lauzon, a PhD candidate ...

Drug improves PTSD traits in rat model of explosive blasts

January 29, 2018
Male rats exposed to air blasts designed to mimic those from explosives used in recent military conflicts have symptoms of post-traumatic stress disorder (PTSD) that are improved by a drug currently being evaluated in humans ...

Hunting for the brain's opioid addiction switch

May 31, 2016
New research by Steven Laviolette's research team at Western University is contributing to a better understanding of the ways opiate-class drugs modify brain circuits to drive the addiction cycle. Using rodent models of opiate ...

Investigators identify neural circuit, genetic 'switch' that maintain memory precision

March 12, 2018
Investigators from the Massachusetts General Hospital (MGH) Center for Regenerative Medicine and the Harvard Stem Cell Institute (HSCI) have identified a neural circuit mechanism involved in preserving the specificity of ...

Fear memories made too quickly may be at heart of memory disorders

March 16, 2017
Research by neuroscientists at UTS, the University of Sydney and the Garvan Institute has revealed a new insight into fear memories that might help to explain how disorders such as post-traumatic stress disorder (PTSD) arise ...

Recommended for you

Schadenfreude sheds light on darker side of humanity

October 23, 2018
Schadenfreude, the sense of pleasure people derive from the misfortune of others, is a familiar feeling to many—perhaps especially during these times of pervasive social media.

Is big-city living eroding our nice instinct?

October 23, 2018
A new study by University of Miami psychology researchers of anonymous interactions suggests that humans switch off their automatic inclination to share in dealings with strangers.

Does putting the brakes on outrage bottle up social change?

October 23, 2018
While outrage is often generally considered a hurdle in the path to civil discourse, a team of psychologists suggest outrage—specifically, moral outrage—may have beneficial outcomes, such as inspiring people to take part ...

Brain training app helps reduce OCD symptoms, study finds

October 23, 2018
A 'brain training' app developed at the University of Cambridge could help people who suffer from obsessive compulsive disorder (OCD) manage their symptoms, which may typically include excessive handwashing and contamination ...

Closing the gender gap in competitiveness with a psychological trick

October 23, 2018
Women are still disadvantaged in society, particularly professionally. They are frequently paid less than men and find it more difficult to have a successful career. One reason for this may be the fact that women are observed ...

First impressions count, new speech research confirms

October 22, 2018
Human beings make similar judgements of the trustworthiness and dominance of an unfamiliar speaker after hearing just a single word, new research shows, suggesting the old saying that 'first impressions count' might well ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.