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The researchers hypothesize that this negative hedonic state, and the activation of the PVT in the brain as a response, is critical for how the brain learns and perpetuates addiction. Credit: Neuroscience News<\/p>\nSummary: A new study highlights how the brain learns to keep alcohol addiction going, not for pleasure but to escape withdrawal stress. Researchers found that a midline brain region, the PVT, became especially active when rats associated alcohol with relief from withdrawal, driving strong relapse behavior.<\/p>\n
This shows that negative reinforcement, not just positive reward, plays a key role in addiction persistence. The findings could open new avenues for treating substance use disorders and other stress-driven behaviors.<\/p>\n
Key Facts<\/p>\n
Brain Circuit Identified: The PVT lights up when alcohol is linked to relief from withdrawal stress.Relapse Driver: Addiction persists because alcohol relieves negative states, not just provides pleasure.Wider Impact: Findings may inform treatments for substance use disorders, anxiety, and stress-driven cycles.<\/p>\n
Source: Scripps Research Institute<\/p>\n
What compels someone to keep engaging in alcohol use, even if it damages their health, relationships and wellbeing? <\/p>\n
A new study from Scripps Research offers an important clue: a small midline brain region plays a key role in how animals learn to continue drinking to avoid the stress and misery of withdrawal.<\/p>\n
The researchers hypothesize that this negative hedonic state, and the activation of the PVT in the brain as a response, is critical for how the brain learns and perpetuates addiction. Credit: Neuroscience News<\/p>\n
In a new study,\u00a0published in\u00a0Biological Psychiatry: Global Open Science\u00a0on August 5, 2025, the Scripps Research\u00a0team\u00a0zeroed in on a set of brain cells in the paraventricular nucleus of the thalamus (PVT) in rats.<\/p>\n
They found that this region becomes more active, driving strong relapse behavior, when rats learn to associate environmental stimuli with the easing of withdrawal symptoms by alcohol.<\/p>\n
By illuminating this brain pathway, the research sheds light on one of the most stubborn features of addiction\u2014drinking not for pleasure, but to escape pain\u2014and could eventually lead to new treatments for substance use disorders (SUDs) as well as other maladaptive behaviors including anxiety.<\/p>\n
\u201cWhat makes addiction so hard to break is that people aren\u2019t simply chasing a high,\u201d says\u00a0Friedbert Weiss,\u00a0professor of neuroscience at Scripps Research and senior author of the study. \u201cThey\u2019re also trying to get rid of powerful negative states, like the stress and anxiety of withdrawal. This work shows us which brain systems are responsible for locking in that kind of learning, and why it can make relapse so persistent.\u201d<\/p>\n
\u201cThis brain region just lit up in every rat that had gone through withdrawal-related learning,\u201d says co-senior author Hermina Nedelescu of Scripps Research. \u201cIt shows us which circuits are recruited when the brain links alcohol with relief from stress\u2014and that could be a game-changer in how we think about relapse.\u201d<\/p>\n
From behavior to brain maps<\/p>\n
An estimated\u00a014.5 million people\u00a0in the United States have alcohol use disorder, which encompasses a range of unhealthy drinking behaviors. Like other drug addictions, alcohol addiction is characterized by cycles of withdrawal, abstinence and relapse.\u00a0<\/p>\n
In 2022, Weiss and Nedelescu used rats to study the types of learning that happen in the brain throughout this cycle. When rats initially begin drinking, they learn to associate pleasure with alcohol and seek more. However, that conditioning becomes far stronger during multiple cycles of withdrawal and relapse.<\/p>\n
After learning that alcohol eased the unpleasant feelings of withdrawal\u2014what scientists call negative reinforcement or a relief of \u2018negative hedonic state\u2019\u2014the animals sought out more alcohol and would remain persistent even when uncomfortable.<\/p>\n
\u201cWhen rats learn to associate environmental stimuli or contexts with the experience of relief, they end up with an incredibly powerful urge to seek alcohol in the presence of that stimuli \u2013even if conditions are introduced that require great effort to engage in alcohol seeking,\u201d says Weiss. \u201cThat is, these rats seek alcohol even if that behavior is punished.\u201d<\/p>\n
In the new work, the team wanted to pin down exactly what networks of cells in the brain were responsible for learning to associate environmental cues with the relief of this negative hedonic state.<\/p>\n
The researchers used advanced imaging tools to scan entire rat brains, cell by cell, and pinpoint areas that became more active in response to alcohol-related cues. They compared four groups of rats: those that had gone through withdrawal and learned that alcohol relieves a negative hedonic state, and three different control groups that had not.<\/p>\n
While several brain areas showed increased activity in the withdrawal-learned rats, one stood out: the PVT, which is known for its role in stress and anxiety.<\/p>\n
\u201cIn retrospect, this makes a lot of sense,\u201d says Nedelescu. \u201cThe unpleasant effects of alcohol withdrawal are strongly associated with stress, and alcohol is providing relief from the agony of that stressful state.\u201d<\/p>\n
The researchers hypothesize that this negative hedonic state, and the activation of the PVT in the brain as a response, is critical for how the brain learns and perpetuates addiction.<\/p>\n
A better understanding of addiction<\/p>\n
The implications of the new study extend well beyond alcohol, the researchers say. Environmental stimuli conditioned to negative reinforcement\u2014the drive to act in order to escape pain or stress\u2014is a universal feature of the brain, and can drive human behavior beyond substance use disorders such as anxiety disorders, fear-conditioning and traumatic avoidance learning.<\/p>\n
\u201cThis work has potential applications not only for alcohol addiction, but also other disorders where people get trapped in harmful cycles,\u201d says Nedelescu.<\/p>\n
Future research will zoom in even further. Nedelescu and colleagues at Scripps Research want to expand the study to females and to study neurochemicals released in the PVT when subjects encounter environments associated with the experience of this relief from a negative hedonic state. If they can pinpoint molecules that are involved, it could open new avenues for drug development by targeting those molecules.<\/p>\n
For now, the new study underscores a key shift in how basic scientists think about addiction.<\/p>\n
\u201cAs psychologists, we\u2019ve long known that addiction isn\u2019t just about chasing pleasure\u2014it\u2019s about escaping those negative hedonic states,\u201d says Weiss. \u201cThis study shows us where in the brain that learning takes root, which is a step forward.\u201d<\/p>\n
Funding: This work was supported by funding from the National Institutes of Health (Ruth L. Kirschstein Institutional National Research Service Award T32AA007456, K01 DA054449, R01 AA027555, and R01 AA023183).<\/p>\n
About this neuroscience and addiction research news<\/p>\n
Author: Press Office<\/a>
Source: Scripps Research Institute<\/a>
Contact: Press Office \u2013 Scripps Research Institute
Image: The image is credited to Neuroscience News<\/p>\n