It is an important hormone that helps our body fight against stress and any threatening situations. But, excess levels of stress generated by cortisol keeps the norepinephrine in high level and our body in the state of fight. As a result our immune system becomes weak making us prone to anxiety, depression and disorders like kidney damage, heart disease etc.
Excess cortisol and chronic stress reduces the dopamine levels. Dopamine is a vital chemical messenger responsible for transmitting signals between the nerve cells (neurons) of the brain. Low dopamine results in apathy, mood swings, fatigue, reduced sensation of rewards, and pleasure.
It is a chemical that boosts wellbeing and happiness. But, reduction in serotonin due to high stress and cortisol results in a bad mood, loss of appetite, fatigue, poor social behavior, and depression. Also, people with depression are found to have low serotonin levels, which is why this chemical plays a great role in the treatment of depression.
Depression also reduces certain GABA neurotransmitters with evidence pointing to an association between major depressive disorders and diverse types of GABAergic deficits.
As you can see high cortisol and stress not only affects the mind to cause depression but affects the whole body.
The Continuous cycle of stress and depression
Depression can be viewed as a vicious cycle. High stress stimulates cortisol, which leads to hormonal and chemical imbalances that affect appetite, sleep cycle, the sense of pleasure, decision-making, mood, interest in activities like exercise that can reduce depression. It means stress induces behaviors that cause depression and depression further fuels stress.
There is a need for effective intervention to manage depression because it doesn’t just affect the mind and brain but the whole body to some extent. This state of mind is more than just being sad or having low-self-esteem. If left untreated, depression can lead to suicide.