Brain Reward, Societal Trauma, and Resilience

Brain Reward, Societal Trauma, and Resilience

By Ana Duarte, Jim Stellar and Arezoo Hajighorbani 

In 2021 a paper was published that points out the long-known clinical comorbidity between trauma and substance use. The paper particularly focused on the reward systems in the brain and how trauma, and (maybe PTSD) might alter the brain’s reward circuits to make drug use (perhaps cocaine) more likely. We thought that insight gave us an entrance into the cognitive-emotional connections about which this blog series is generally about even though the series focus more on the impact of experiential education. 

This particular blog builds on three trauma-topic related blog posts, two recent posts (one by AH and one by AD) and one slightly older post. What is the main point here is how does trauma relate to stress especially when that trauma comes societally as a slow-moving and persistent effect, but no less difficult than recovering from sudden trauma and maybe worse?

In this blog, we first review two papers suggesting brain areas that are involved with tenacity and resilience to trauma. We pay special attention to reward-related impacts on trauma, looking for evidence that the functioning of the reward system might at least partially abate the brain circuits of trauma. 

Our first paper is a 2021 review paper on Post Traumatic Stress Disorder (PTSD) and Substance Use Disorder (SUD), the authors argued that these patients have suppressed reward systems. To begin, the authors discuss PTSD pointing out that many of the symptoms reflect a state of hyperarousal with increased stress hormones, such as corticotrophin releasing factor and noradrenaline, and increased function in the amygdala (fear) with decreased function in the neocortex (executive control), and that becomes a sensitized neuronal reaction. Meanwhile, for SUD, the authors point out that in reward-seeking the incentive-sensitization models predict a hyper-craving or “wanting” that unbalances and dominates normal reward processing or “liking.” The point here is that in PTSD there is a reduced processing of reward leaving the patient vulnerable to reward-enhancing (and sensitizing) drug experiences that leads to SUD on top of PTSD. PTSD patients, they say, “spend less time engaging in reward-seeking behavior compared to normals, report lower levels of reward expectation, and are less satisfied with monetized rewards.” They go on to say that studies on animals seem to agree with studies on human brain scans in this regard. What we would say here is that perhaps by increasing normal reward experiences (not to lead to drug use) or perhaps by inherently having a resilient reward-related neural function one could address some of the deficiencies created by any trauma, especially societal.

Our second paper is a slightly older 2018 comprehensive review paper on neuroimaging structure and function and focusing on traumatic events (e.g. PTSD) and resilience. In a comparison between PTSD and normals, they say “… increased amygdala and anterior cingulate cortex activities, and decreased prefrontal cortex activity as a response to external stimuli have been associated with higher vulnerability. Increased prefrontal cortex activity seemed to be a protective factor.” The focus on the anterior cingulate cortex (ACC) is interesting given its general reputation for being involved with emotional conflict. The prefrontal cortex, with its general reputation of executive functioning, is expected and was discussed above. Changes in other relevant areas such as hippocampus (memory) and insula cortex (risk) were also noted in this review. What was particularly interesting is that they also looked at the Default Mode Network (DMN) which is self-referential and was first associated with mind-wandering when no task was present. Here the authors say “weak connectivity between danger-sensitive and self referential networks might thus be a neurofunctional indicator of increased resilience.” Perhaps greater emotional regulation is part of this resilience and the “…the ability to consciously recruit brain areas associated with positive emotional experience during presentation of negative stimuli.” If the ACC plays a role in resilience from stress and it also underlies emotional intelligence (EQ) than perhaps EQ is a path out of societal stress, particularly if one can find positives in one’s life. Again, does this observation speak to the way reward experiences or a resilience within the reward system can provide.

From a personal perspective and on the duality of the hardship and hope AD writes, “There were certain safety concerns in my community that I constantly dealt with as a young child. The first, was the house of squatters that was located directly across the street from my childhood home. For the most part –  the body of drunken characters typically kept to themselves. That said, I was well aware that alcoholism could lead to outrage and unpredictable behavior. I witnessed the  destitution of alcoholism and institutional racism in my own home. My community was once the epicenter of substance abuse and the cascade of events that resulted from that institutional racism. At dusk, my neighborhood became increasingly dangerous by each passing hour, particularly at the junction of Centre and Day Street. I often visit the now gentrified Jamaica Plain area where High Low Market is now replaced by Whole Foods and a once popular Cuban Restaurant- El Oriental no longer exists. Occasionally I come across the smell of plantains and the lull brought on by Merengue music and the sight of low riders. I often notice a particular reaction that is familiar as I pass Centre and Day Street. My palms start to sweat and my heart reacts by increasing its number of beats. The rush of adrenaline and flight or fight is automatic without any particular threat.”

From a brain mechanism perspective, JS writes based on his old doctoral thesis that “Approaching and withdrawing systems in the brain seem to be in a natural oppositional balance to each other, ranging from basic reflexes to the most voluntary of operant behavior. The lateral hypothalamus, which when stimulated produces positive emotions, is clearly in a mutual neural inhibitory relationship with the medial hypothalamus, which when stimulated produces negative emotions. Higher in the brain, the cortex also seems to sort out for planning purposes what experiences are good for you and which ones are not. Finally in a dramatic demonstration of this interaction, if you are engaged fully (and having fun) it is often the case that you do not feel a small injury, like cutting your foot on a sharp shell while you are playing beach volleyball. So the hope here is that pleasurable experiences, particularly goals that you can achieve, can somehow mitigate the negative stamp put upon the brain by trauma and promotes resilience.”

From a societal perspective AH writes “When considering societal and slow-moving trauma, I reflect on the constant oppression faced by women in my home country. From an early age, witnessing the legal and social restrictions imposed on women while males enjoy greater freedom slowly shapes a deep-seated trauma. This has always fascinated me, particularly in understanding how women cope with such trauma. In Iran, young women are increasingly smoking cigarettes, a behavior linked to a sense of power and control over their bodies, which are otherwise strictly regulated by society. Reduced reward processing in PTSD patients makes them more likely to seek out substances that enhance feelings of reward. Since achieving freedom is often impossible for Iranian women, smoking cigarettes provides a form of relief from the constant fear and oppression they face in society. For many Iranian women, smoking acts as a reward-seeking behavior, a way to reclaim autonomy. Interestingly, when these women immigrate to freer countries, the urge to smoke often diminishes. This change underscores that smoking and nicotine use among these women are more than mere habits—they are responses to trauma and a means to assert control.” 

In summary, we think resilience can come from many places in psychology and the brain, but one of them could well be from reward experiences themselves. For us, that idea opens up a way to use this limbic system function to counter the other negative limbic system functions that trap a person’s thinking by the continuous and persistent brain effects of societal trauma whether episodic or the product of long societal influences from injustices such as racism and sexism. The neuroscience and psychology of this type of cognitive-emotional integration will be the subject of our future blogs.