A recent study shows that individuals without depression,unlike those with the condition, adapt to elevated everyday stress by changes in the response of the medial prefrontal cortex, a brain region involved in regulating the stress response.
An inability to produce an adaptive response to elevated everyday stress may lead to depression.
The extent of this inability to produce an adaptive response to stress may predict deficits in daily functioning.
Major depressive disorder (MDD), also known as clinical depression, is one of the most common mental health conditions in the United States.
According to the National Institute of Mental Health (NIMH), approximately 7.1% of adults had a depressive episode in 2017.
Furthermore, recent researchTrusted Source carried out by the Centers for Disease Control and Prevention (CDC) suggests the stress of the current COVID-19 pandemic may be associated with an increase in self-reported depression and anxiety symptoms, particularly in adults under 30 years old.
Experiencing stress over a prolonged period, such as during the pandemic, is associated with the development of depression.
One of the major symptoms of depression includes anhedonia, or the inability to anticipate or feel pleasure.
However, researchers do not have a comprehensive understanding of how chronic stress leads to depression or the accompanying symptoms of anhedonia.
Evidence suggests that the medial prefrontal cortex (mPFC), a brain region involved in processing reward and regulating the stress response, may be involved in mediating these effects of chronic stress.
While the mPFC is involved in regulating the stress response, acute and chronic stress also elicit changes in the mPFC.
Studies in rodents have shown that glutamate, an excitatory neurotransmitter, is released by neurons in the mPFC during acute stress.
However, rodents exposed to chronic stress exhibit lower levels of glutamate release in the mPFC when faced with a new acute stressful event.
Scientists think that such a reduction in the mPFC glutamate response due to chronic stress could be a protective adaptation to stress.
StudiesTrusted Source had already shown that mPFC glutamate activity is altered in depression.