The two disorders are known to be linked, although it is not clear how chronic stress leads to depression. A recent study demonstrated the response of the medial prefrontal cortex and the release of glutamate as a result of stressful situations that can lead to depression.
stress and depression
The depression It represents an important public health problem, due to its high prevalence. It is known that genetic, psychological and biological factors intervene in its genesis.
Among the psychosocial factors, it has been observed that the appearance of the first depressive manifestations becomes apparent after some stressful event, and this stress accompanying the first episode causes changes in brain physiology.
These changes are generated at the structural and functional level of different brain regions and are maintained over the long term.
Overall, it is estimated that 1 in 6 adults will experience depression at some point in their lives, as anyone is at risk of developing depression for various reasons.
Additionally, recent research by the Centers for Disease Control and Prevention (CDC) has shown that stress, as a result of the COVID-19 pandemic, may be associated with increased symptoms of stress and depression. Added to this is a heightened state of anxiety, especially in adults under 30 years of age.
Exposure to stress for a long time has been associated with the development of depression, with symptoms such as anhedonia It is the inability to anticipate or feel pleasure.
Inability to cope with stress and depression
But a recent study appeared in the journal nature, led by a team of researchers from Emory University in the US, shows that people who do not suffer from depression adapt to high daily stress through changes in their response to depression. Prefrontal medial cortisol (mPFC).
This is a brain area involved in regulating stress response, so The inability to generate an appropriate adaptive response to high levels of daily stress can lead to depression.
On the other hand, studies in rodents have shown that glutamate, a neurotransmitter with an excitatory effect, is released by neurons in the mPFC in response to acute tension.
However, when the rodents were exposed to chronic stress, they released lower levels of glutamate in the mPFC than when faced with a new acute stress event.
Although there were previous studies that showed that the glutamate activity of the mPFC protein changes in depression, this study reaffirmed the link between stress and depression, as well as finding a biochemical basis.
This decrease in the glutamate release response in the mPFC due to chronic stress could constitute an adaptive protection mechanism against stress.
It has been shown that depressed subjects cannot induce an adaptive decrease in glutamate levels from the mPFC, in the face of the recent increase in daily stress.
The researchers suggest that the lack of an adaptive change in glutamate levels in the mPFC may be related to the development of stress-related mental disorders and depression.
However, researchers do not fully understand how chronic stress leads to depression or symptoms associated with anhedonia.
Anhedonia, stress and depression
From a physiological point of view, anhedonia is caused by a change in brain chemistry, Inhibits dopamine synthesis, a neurotransmitter associated with pleasurable sensations.
In cases of depression, extreme stress or excessive anxiety, the brain cannot produce this substance, which ends up affecting all activities of daily living.
Therefore, anhedonia is one of the main symptoms to determine the diagnosis of depression.
When the loss of response to pleasurable sensations is not generalized, but affects a particular aspect, it can be explained by other causes. For example, loss of sexual pleasure or food taste can occur due to the use of certain medications, such as antidepressants.
In short, it is clear that the consequences of stress and depression can ultimately severely impact the quality of life of those who suffer from it, which has become a worrisome public health problem worldwide.
This evidence in the study of the relationship between stress and depression could represent a starting point in terms of new findings that further expand their knowledge and understanding, in order to treat these common conditions more efficiently.