Can Control Over Stress Reactivity Lead to Prevention of Mental Disorders?

    There are numerous studies past and present that postulate the idea that stress is significantly associated with a higher risk for mental disorder development. Numerous reviews, experiments, and articles all point to the need for more research into understanding the basis for the connection between stress and increased mental disorders. The discoveries made indicate that to best be able to understand the connection, one must look to the hypothalamic-pituitary-adrenal (HPA) axis, the ventral tegmental area (VTA), as well as the mesolimbic pathway (specifically the neural reward circuit).

    In the article "Risk and Resilience in an Acute Stress Paradigm: Evidence from Salivary Cortisol and Time-Frequency Analysis of the Reward Positivity," by Ethridge et. al. (2020), the researchers looked for the association between the HPA-axis stress response and Event-Related Potentials (ERPs) that would show activity during reward-related feedback. The specific ERP used was the reward positivity (RewP), for the measure of reward processing. The researchers hypothesized that psychosocial stressors could lead to reduced RewPs, and in opposite association, awareness of reward would lead to less reactivity to stressors. The results of the study showed that it coincided with past research, and that a bidirectional relationship could be suggested between the HPA-axis response for stress as well as the reward system in the brain. However, it was important to mention that there was also an association between the stress response and losses (alongside gains). This study mentioned that dopamine neurons in the VTA were activated in both the stress response as well as reward processing of a brain. Another interesting point from this article for further study was that there was a presence of sexual dimorphism in regard to the stress response.

    In the article “Stress-induced plasticity and functioning of ventral tegmental dopamine neurons,” by Douma and Kloet (2019), the researchers provide a review as to why researching the mesolimbic pathway specifically via the VTA dopamine circuit with congruence to stress would prove beneficial. The review highlights how chronic stress can potentially lead to neurodegeneration of the dopamine neurons, which in turn would diminish the function of the behaviors associated with VTA dopamine neuronal circuits. The review also found (for further study) the significance of VTA dopamine neuronal excitation and inhibition when dealing with the reward-response behavior. Finally, this study also emphasized the importance of sexual dimorphism when researching the stress response, as the male and female brain react differently with regard to glucocorticoid production.

    Both studies “stress” the importance of studying the mesolimbic pathway through the VTA dopamine circuit and the HPA-axis for stress reactivity and the reward circuit in order to better understand the neuroscientific basis for mental disorders. While behavioral studies may help gain insight to better deal with mental disorders, if the neurological basis of these mental disorders is expanded upon, then a concurrent process may happen in which both biology and behavior can be studied to effectively diagnose and treat mental disorders before their onset becomes debilitating.

Sources Cited:

Ethridge, P., Ali, N., Racine, S. E., Pruessner, J. C., & Weinberg, A. (2020). Risk and Resilience in an    Acute Stress Paradigm: Evidence From Salivary Cortisol and Time-Frequency Analysis of the Reward Positivity. Clinical Psychological Science, 8(5), 872–889. https://doi.org/10.1177/2167702620917463

Douma, E. H., & de Kloet, E. R. (2020). Stress-induced plasticity and functioning of ventral tegmental dopamine neurons. Neuroscience & Biobehavioral Reviews, 108, 48–77. https://doi.org/10.1016/j.neubiorev.2019.10.015